On Mon, Oct 28, 2019 at 2:13 PM Dilip Kumar <dilipbal...@gmail.com> wrote:
>
> On Thu, Oct 24, 2019 at 4:33 PM Dilip Kumar <dilipbal...@gmail.com> wrote:
> >
> > On Thu, Oct 24, 2019 at 4:21 PM Amit Kapila <amit.kapil...@gmail.com> wrote:
> > >
> > > On Thu, Oct 24, 2019 at 11:51 AM Dilip Kumar <dilipbal...@gmail.com>
> > > wrote:
> > > >
> > > > On Fri, Oct 18, 2019 at 12:18 PM Dilip Kumar <dilipbal...@gmail.com>
> > > > wrote:
> > > > >
> > > > > On Fri, Oct 18, 2019 at 11:25 AM Amit Kapila
> > > > > <amit.kapil...@gmail.com> wrote:
> > > > > >
> > > > > > I am thinking if we can write the patch for both the approaches (a.
> > > > > > compute shared costs and try to delay based on that, b. try to
> > > > > > divide
> > > > > > the I/O cost among workers as described in the email above[1]) and
> > > > > > do
> > > > > > some tests to see the behavior of throttling, that might help us in
> > > > > > deciding what is the best strategy to solve this problem, if any.
> > > > > > What do you think?
> > > > >
> > > > > I agree with this idea. I can come up with a POC patch for approach
> > > > > (b). Meanwhile, if someone is interested to quickly hack with the
> > > > > approach (a) then we can do some testing and compare. Sawada-san,
> > > > > by any chance will you be interested to write POC with approach (a)?
> > > > > Otherwise, I will try to write it after finishing the first one
> > > > > (approach b).
> > > > >
> > > > I have come up with the POC for approach (a).
>
> > > Can we compute the overall throttling (sleep time) in the operation
> > > separately for heap and index, then divide the index's sleep_time with
> > > a number of workers and add it to heap's sleep time? Then, it will be
> > > a bit easier to compare the data between parallel and non-parallel
> > > case.
> I have come up with a patch to compute the total delay during the
> vacuum. So the idea of computing the total cost delay is
>
> Total cost delay = Total dealy of heap scan + Total dealy of
> index/worker; Patch is attached for the same.
>
> I have prepared this patch on the latest patch of the parallel
> vacuum[1]. I have also rebased the patch for the approach [b] for
> dividing the vacuum cost limit and done some testing for computing the
> I/O throttling. Attached patches 0001-POC-compute-total-cost-delay
> and 0002-POC-divide-vacuum-cost-limit can be applied on top of
> v31-0005-Add-paralell-P-option-to-vacuumdb-command.patch. I haven't
> rebased on top of v31-0006, because v31-0006 is implementing the I/O
> throttling with one approach and 0002-POC-divide-vacuum-cost-limit is
> doing the same with another approach. But,
> 0001-POC-compute-total-cost-delay can be applied on top of v31-0006 as
> well (just 1-2 lines conflict).
>
> Testing: I have performed 2 tests, one with the same size indexes and
> second with the different size indexes and measured total I/O delay
> with the attached patch.
>
> Setup:
> VacuumCostDelay=10ms
> VacuumCostLimit=2000
>
> Test1 (Same size index):
> create table test(a int, b varchar, c varchar);
> create index idx1 on test(a);
> create index idx2 on test(b);
> create index idx3 on test(c);
> insert into test select i, repeat('a',30)||i, repeat('a',20)||i from
> generate_series(1,500000) as i;
> delete from test where a < 200000;
>
> Vacuum (Head) Parallel Vacuum
> Vacuum Cost Divide Patch
> Total Delay 1784 (ms) 1398(ms)
> 1938(ms)
>
>
> Test2 (Variable size dead tuple in index)
> create table test(a int, b varchar, c varchar);
> create index idx1 on test(a);
> create index idx2 on test(b) where a > 100000;
> create index idx3 on test(c) where a > 150000;
>
> insert into test select i, repeat('a',30)||i, repeat('a',20)||i from
> generate_series(1,500000) as i;
> delete from test where a < 200000;
>
> Vacuum (Head) Parallel Vacuum
> Vacuum Cost Divide Patch
> Total Delay 1438 (ms) 1029(ms)
> 1529(ms)
>
>
> Conclusion:
> 1. The tests prove that the total I/O delay is significantly less with
> the parallel vacuum.
> 2. With the vacuum cost divide the problem is solved but the delay bit
> more compared to the non-parallel version. The reason could be the
> problem discussed at[2], but it needs further investigation.
>
> Next, I will test with the v31-0006 (shared vacuum cost) patch. I
> will also try to test different types of indexes.
>
Thank you for testing!
I realized that v31-0006 patch doesn't work fine so I've attached the
updated version patch that also incorporated some comments I got so
far. Sorry for the inconvenience. I'll apply your 0001 patch and also
test the total delay time.
Regards,
--
Masahiko Sawada
From 9da5930da73a1ea10ad8e782171fb8e10a333b0a Mon Sep 17 00:00:00 2001
From: Masahiko Sawada <sawada.m...@gmail.com>
Date: Tue, 15 Oct 2019 17:03:22 +0900
Subject: [PATCH v32 1/4] Add index AM field and callback for parallel index
vacuum
---
contrib/bloom/blutils.c | 3 ++
doc/src/sgml/indexam.sgml | 21 ++++++++++++++
src/backend/access/brin/brin.c | 3 ++
src/backend/access/gin/ginutil.c | 3 ++
src/backend/access/gist/gist.c | 3 ++
src/backend/access/hash/hash.c | 3 ++
src/backend/access/index/indexam.c | 29 +++++++++++++++++++
src/backend/access/nbtree/nbtree.c | 3 ++
src/backend/access/spgist/spgutils.c | 3 ++
src/include/access/amapi.h | 13 +++++++++
src/include/access/genam.h | 1 +
.../modules/dummy_index_am/dummy_index_am.c | 3 ++
12 files changed, 88 insertions(+)
diff --git a/contrib/bloom/blutils.c b/contrib/bloom/blutils.c
index 3d44616adc..d50122d9e2 100644
--- a/contrib/bloom/blutils.c
+++ b/contrib/bloom/blutils.c
@@ -120,7 +120,9 @@ blhandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = false;
amroutine->ampredlocks = false;
amroutine->amcanparallel = false;
+ amroutine->amcanparallelvacuum = true;
amroutine->amcaninclude = false;
+ amroutine->amusemaintenanceworkmem = false;
amroutine->amkeytype = InvalidOid;
amroutine->ambuild = blbuild;
@@ -144,6 +146,7 @@ blhandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = NULL;
amroutine->aminitparallelscan = NULL;
amroutine->amparallelrescan = NULL;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
diff --git a/doc/src/sgml/indexam.sgml b/doc/src/sgml/indexam.sgml
index dd54c68802..df4cad11b3 100644
--- a/doc/src/sgml/indexam.sgml
+++ b/doc/src/sgml/indexam.sgml
@@ -120,8 +120,12 @@ typedef struct IndexAmRoutine
bool ampredlocks;
/* does AM support parallel scan? */
bool amcanparallel;
+ /* does AM support parallel vacuum? */
+ bool amcanparallelvacuum;
/* does AM support columns included with clause INCLUDE? */
bool amcaninclude;
+ /* does AM use maintenance_work_mem? */
+ bool amusemaintenanceworkmem;
/* type of data stored in index, or InvalidOid if variable */
Oid amkeytype;
@@ -149,6 +153,9 @@ typedef struct IndexAmRoutine
amestimateparallelscan_function amestimateparallelscan; /* can be NULL */
aminitparallelscan_function aminitparallelscan; /* can be NULL */
amparallelrescan_function amparallelrescan; /* can be NULL */
+
+ /* interface functions to support parallel vacuum */
+ amestimateparallelvacuum_function amestimateparallelvacuum; /* can be NULL */
} IndexAmRoutine;
</programlisting>
</para>
@@ -731,6 +738,20 @@ amparallelrescan (IndexScanDesc scan);
the beginning.
</para>
+ <para>
+<programlisting>
+void
+amestimateparallelvacuum (IndexScanDesc scan);
+</programlisting>
+ Estimate and return the number of bytes of dynamic shared memory which the
+ access method will be needed to copy the statistics to.
+ </para>
+
+ <para>
+ It is not necessary to implement this function for access methods which
+ do not support parallel vacuum or in cases where the access method does not
+ require more than size of <structname>IndexBulkDeleteResult</structname>.
+ </para>
</sect1>
<sect1 id="index-scanning">
diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index ae7b729edd..4a3286bfde 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -100,7 +100,9 @@ brinhandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = false;
amroutine->ampredlocks = false;
amroutine->amcanparallel = false;
+ amroutine->amcanparallelvacuum = true;
amroutine->amcaninclude = false;
+ amroutine->amusemaintenanceworkmem = false;
amroutine->amkeytype = InvalidOid;
amroutine->ambuild = brinbuild;
@@ -124,6 +126,7 @@ brinhandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = NULL;
amroutine->aminitparallelscan = NULL;
amroutine->amparallelrescan = NULL;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index cf9699ad18..a28a71999d 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -52,7 +52,9 @@ ginhandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = false;
amroutine->ampredlocks = true;
amroutine->amcanparallel = false;
+ amroutine->amcanparallelvacuum = true;
amroutine->amcaninclude = false;
+ amroutine->amusemaintenanceworkmem = true;
amroutine->amkeytype = InvalidOid;
amroutine->ambuild = ginbuild;
@@ -76,6 +78,7 @@ ginhandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = NULL;
amroutine->aminitparallelscan = NULL;
amroutine->amparallelrescan = NULL;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 0cc87911d6..752b5bc88c 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -74,7 +74,9 @@ gisthandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = true;
amroutine->ampredlocks = true;
amroutine->amcanparallel = false;
+ amroutine->amcanparallelvacuum = true;
amroutine->amcaninclude = true;
+ amroutine->amusemaintenanceworkmem = false;
amroutine->amkeytype = InvalidOid;
amroutine->ambuild = gistbuild;
@@ -98,6 +100,7 @@ gisthandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = NULL;
amroutine->aminitparallelscan = NULL;
amroutine->amparallelrescan = NULL;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index 5cc30dac42..dc0dc312ef 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -73,7 +73,9 @@ hashhandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = false;
amroutine->ampredlocks = true;
amroutine->amcanparallel = false;
+ amroutine->amcanparallelvacuum = true;
amroutine->amcaninclude = false;
+ amroutine->amusemaintenanceworkmem = false;
amroutine->amkeytype = INT4OID;
amroutine->ambuild = hashbuild;
@@ -97,6 +99,7 @@ hashhandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = NULL;
amroutine->aminitparallelscan = NULL;
amroutine->amparallelrescan = NULL;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index 9dfa0ddfbb..5238b9d38f 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -711,6 +711,35 @@ index_vacuum_cleanup(IndexVacuumInfo *info,
return indexRelation->rd_indam->amvacuumcleanup(info, stats);
}
+/*
+ * index_parallelvacuum_estimate - estimate shared memory for parallel vacuum
+ *
+ * Currently, we don't pass any information to the AM-specific estimator,
+ * so it can probably only return a constant. In the future, we might need
+ * to pass more information.
+ */
+Size
+index_parallelvacuum_estimate(Relation indexRelation)
+{
+ Size nbytes;
+
+ RELATION_CHECKS;
+
+ /*
+ * If amestimateparallelvacuum is not provided, assume only
+ * IndexBulkDeleteResult is needed.
+ */
+ if (indexRelation->rd_indam->amestimateparallelvacuum != NULL)
+ {
+ nbytes = indexRelation->rd_indam->amestimateparallelvacuum();
+ Assert(nbytes >= MAXALIGN(sizeof(IndexBulkDeleteResult)));
+ }
+ else
+ nbytes = MAXALIGN(sizeof(IndexBulkDeleteResult));
+
+ return nbytes;
+}
+
/* ----------------
* index_can_return
*
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 4cfd5289ad..1ea2ba3fe0 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -122,7 +122,9 @@ bthandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = true;
amroutine->ampredlocks = true;
amroutine->amcanparallel = true;
+ amroutine->amcanparallelvacuum = true;
amroutine->amcaninclude = true;
+ amroutine->amusemaintenanceworkmem = false;
amroutine->amkeytype = InvalidOid;
amroutine->ambuild = btbuild;
@@ -146,6 +148,7 @@ bthandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = btestimateparallelscan;
amroutine->aminitparallelscan = btinitparallelscan;
amroutine->amparallelrescan = btparallelrescan;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
diff --git a/src/backend/access/spgist/spgutils.c b/src/backend/access/spgist/spgutils.c
index 45472db147..4a1689859a 100644
--- a/src/backend/access/spgist/spgutils.c
+++ b/src/backend/access/spgist/spgutils.c
@@ -55,7 +55,9 @@ spghandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = false;
amroutine->ampredlocks = false;
amroutine->amcanparallel = false;
+ amroutine->amcanparallelvacuum = true;
amroutine->amcaninclude = false;
+ amroutine->amusemaintenanceworkmem = false;
amroutine->amkeytype = InvalidOid;
amroutine->ambuild = spgbuild;
@@ -79,6 +81,7 @@ spghandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = NULL;
amroutine->aminitparallelscan = NULL;
amroutine->amparallelrescan = NULL;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index 6e3db06eed..d166350bbe 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -156,6 +156,12 @@ typedef void (*aminitparallelscan_function) (void *target);
/* (re)start parallel index scan */
typedef void (*amparallelrescan_function) (IndexScanDesc scan);
+/*
+ * Callback function signatures - for parallel index vacuuming.
+ */
+/* estimate size of parallel index vacuuming memory */
+typedef Size (*amestimateparallelvacuum_function) (void);
+
/*
* API struct for an index AM. Note this must be stored in a single palloc'd
* chunk of memory.
@@ -195,8 +201,12 @@ typedef struct IndexAmRoutine
bool ampredlocks;
/* does AM support parallel scan? */
bool amcanparallel;
+ /* does AM support parallel vacuum? */
+ bool amcanparallelvacuum;
/* does AM support columns included with clause INCLUDE? */
bool amcaninclude;
+ /* does AM use maintenance_work_mem? */
+ bool amusemaintenanceworkmem;
/* type of data stored in index, or InvalidOid if variable */
Oid amkeytype;
@@ -230,6 +240,9 @@ typedef struct IndexAmRoutine
amestimateparallelscan_function amestimateparallelscan; /* can be NULL */
aminitparallelscan_function aminitparallelscan; /* can be NULL */
amparallelrescan_function amparallelrescan; /* can be NULL */
+
+ /* interface functions to support parallel vacuum */
+ amestimateparallelvacuum_function amestimateparallelvacuum; /* can be NULL */
} IndexAmRoutine;
diff --git a/src/include/access/genam.h b/src/include/access/genam.h
index a813b004be..48ed5bbac7 100644
--- a/src/include/access/genam.h
+++ b/src/include/access/genam.h
@@ -179,6 +179,7 @@ extern IndexBulkDeleteResult *index_bulk_delete(IndexVacuumInfo *info,
void *callback_state);
extern IndexBulkDeleteResult *index_vacuum_cleanup(IndexVacuumInfo *info,
IndexBulkDeleteResult *stats);
+extern Size index_parallelvacuum_estimate(Relation indexRelation);
extern bool index_can_return(Relation indexRelation, int attno);
extern RegProcedure index_getprocid(Relation irel, AttrNumber attnum,
uint16 procnum);
diff --git a/src/test/modules/dummy_index_am/dummy_index_am.c b/src/test/modules/dummy_index_am/dummy_index_am.c
index bc68767f3a..374d545f0d 100644
--- a/src/test/modules/dummy_index_am/dummy_index_am.c
+++ b/src/test/modules/dummy_index_am/dummy_index_am.c
@@ -300,7 +300,9 @@ dihandler(PG_FUNCTION_ARGS)
amroutine->amclusterable = false;
amroutine->ampredlocks = false;
amroutine->amcanparallel = false;
+ amroutine->amcanparallelvacuum = false;
amroutine->amcaninclude = false;
+ amroutine->amusemaintenanceworkmem = false;
amroutine->amkeytype = InvalidOid;
amroutine->ambuild = dibuild;
@@ -324,6 +326,7 @@ dihandler(PG_FUNCTION_ARGS)
amroutine->amestimateparallelscan = NULL;
amroutine->aminitparallelscan = NULL;
amroutine->amparallelrescan = NULL;
+ amroutine->amestimateparallelvacuum = NULL;
PG_RETURN_POINTER(amroutine);
}
--
2.22.0
From 279ebab5dc0ad2ce0569bb84a80995257a746b80 Mon Sep 17 00:00:00 2001
From: Masahiko Sawada <sawada.m...@gmail.com>
Date: Fri, 25 Oct 2019 21:56:24 +0900
Subject: [PATCH v32 4/4] PoC: shared vacuum cost balance
---
src/backend/access/heap/vacuumlazy.c | 26 +++++++++++
src/backend/commands/vacuum.c | 67 ++++++++++++++++++++++------
src/include/access/heapam.h | 1 +
3 files changed, 81 insertions(+), 13 deletions(-)
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 0cfa13b81b..a9d9f31887 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -211,6 +211,13 @@ typedef struct LVShared
/* The number of indexes that do NOT support parallel index vacuuming */
int nindexes_nonparallel;
+ /*
+ * Shared vacuum cost balance. During parallel index vacuuming
+ * VacuumSharedCostBalance points to this value and it accumulates the
+ * balance of each parallel vacuum workers.
+ */
+ pg_atomic_uint32 cost_balance;
+
/*
* Variables to control parallel index vacuuming. Index statistics
* returned from ambulkdelete and amvacuumcleanup is nullable variable
@@ -230,6 +237,9 @@ typedef struct LVShared
#define IndStatsIsNull(s, i) \
(!(((LVShared *)(s))->bitmap[(i) >> 3] & (1 << ((i) & 0x07))))
+/* Global variable for shared cost-based vacuum delay */
+pg_atomic_uint32 *VacuumSharedCostBalance = NULL;
+
/*
* Struct for an index bulk-deletion statistic used for parallel lazy
* vacuum. This is allocated in the DSM segment. IndexBulkDeleteResult
@@ -1961,6 +1971,14 @@ lazy_parallel_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
Assert(ParallelVacuumIsActive(lps));
Assert(nindexes > 0);
+ /*
+ * Move the current balance to the shared value and enable shared cost
+ * balance.
+ */
+ pg_atomic_write_u32(&(lps->lvshared->cost_balance), VacuumCostBalance);
+ VacuumCostBalance = 0;
+ VacuumSharedCostBalance = &(lps->lvshared->cost_balance);
+
LaunchParallelWorkers(lps->pcxt);
if (lps->lvshared->for_cleanup)
@@ -1987,6 +2005,12 @@ lazy_parallel_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
/* Wait for all vacuum workers to finish */
WaitForParallelWorkersToFinish(lps->pcxt);
+ /* Disable shared cost balance for vacuum delay */
+ VacuumSharedCostBalance = NULL;
+
+ /* Continue to use the shared balance value */
+ VacuumCostBalance = pg_atomic_read_u32(&(lps->lvshared->cost_balance));
+
/*
* We need to reinitialize the parallel context as no more index vacuuming and
* index cleanup will be performed after that.
@@ -3000,6 +3024,7 @@ begin_parallel_vacuum(LVRelStats *vacrelstats, Oid relid, BlockNumber nblocks,
shared->offset = add_size(SizeOfLVShared, BITMAPLEN(nindexes));
prepare_index_statistics(shared, Irel, nindexes);
pg_atomic_init_u32(&(shared->nprocessed), 0);
+ pg_atomic_init_u32(&(shared->cost_balance), 0);
shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_SHARED, shared);
lps->lvshared = shared;
@@ -3188,6 +3213,7 @@ heap_parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
VacuumPageHit = 0;
VacuumPageMiss = 0;
VacuumPageDirty = 0;
+ VacuumSharedCostBalance = &(lvshared->cost_balance);
stats = (IndexBulkDeleteResult **)
palloc0(nindexes * sizeof(IndexBulkDeleteResult *));
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 9ada501709..1b9ea9b672 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -412,6 +412,7 @@ vacuum(List *relations, VacuumParams *params,
VacuumPageHit = 0;
VacuumPageMiss = 0;
VacuumPageDirty = 0;
+ VacuumSharedCostBalance = NULL;
/*
* Loop to process each selected relation.
@@ -1990,28 +1991,68 @@ vac_close_indexes(int nindexes, Relation *Irel, LOCKMODE lockmode)
void
vacuum_delay_point(void)
{
+ double msec = 0;
+
/* Always check for interrupts */
CHECK_FOR_INTERRUPTS();
- /* Nap if appropriate */
- if (VacuumCostActive && !InterruptPending &&
- VacuumCostBalance >= VacuumCostLimit)
+ if (VacuumCostActive && !InterruptPending)
{
- double msec;
+ /*
+ * If the vacuum cost balance is shared among parallel workers we
+ * decide whether to sleep based on that.
+ */
+ if (VacuumSharedCostBalance != NULL)
+ {
+ while (true)
+ {
+ uint32 shared_balance;
+ uint32 new_balance;
- msec = VacuumCostDelay * VacuumCostBalance / VacuumCostLimit;
- if (msec > VacuumCostDelay * 4)
- msec = VacuumCostDelay * 4;
+ msec = 0;
- pg_usleep((long) (msec * 1000));
+ /* compute new balance by adding the local value */
+ shared_balance = pg_atomic_read_u32(VacuumSharedCostBalance);
+ new_balance = shared_balance + VacuumCostBalance;
- VacuumCostBalance = 0;
+ if (new_balance >= VacuumCostLimit)
+ {
+ /* compute sleep time based on the shared cost balance */
+ msec = VacuumCostDelay * new_balance / VacuumCostLimit;
+ new_balance %= VacuumCostLimit;
+ }
- /* update balance values for workers */
- AutoVacuumUpdateDelay();
+ if (pg_atomic_compare_exchange_u32(VacuumSharedCostBalance,
+ &shared_balance,
+ new_balance))
+ break;
+ }
- /* Might have gotten an interrupt while sleeping */
- CHECK_FOR_INTERRUPTS();
+ /*
+ * Reset the local balance as we accumulated it into the shared
+ * value.
+ */
+ VacuumCostBalance = 0;
+ }
+ else if (VacuumCostBalance >= VacuumCostLimit)
+ msec = VacuumCostDelay * VacuumCostBalance / VacuumCostLimit;
+
+ /* Nap if appropriate */
+ if (msec > 0)
+ {
+ if (msec > VacuumCostDelay * 4)
+ msec = VacuumCostDelay * 4;
+
+ pg_usleep((long) (msec * 1000));
+
+ VacuumCostBalance = 0;
+
+ /* update balance values for workers */
+ AutoVacuumUpdateDelay();
+
+ /* Might have gotten an interrupt while sleeping */
+ CHECK_FOR_INTERRUPTS();
+ }
}
}
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 12065cc038..ac883f67d1 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -192,6 +192,7 @@ extern void SyncScanShmemInit(void);
extern Size SyncScanShmemSize(void);
/* in heap/vacuumlazy.c */
+extern pg_atomic_uint32 *VacuumSharedCostBalance;
struct VacuumParams;
extern void heap_vacuum_rel(Relation onerel,
struct VacuumParams *params, BufferAccessStrategy bstrategy);
--
2.22.0
From d17fc1ed9c2255800f993814bb6e1502045c39e4 Mon Sep 17 00:00:00 2001
From: Masahiko Sawada <sawada.m...@gmail.com>
Date: Wed, 23 Jan 2019 16:07:53 +0900
Subject: [PATCH v32 3/4] Add --paralell, -P option to vacuumdb command
---
doc/src/sgml/ref/vacuumdb.sgml | 16 +++++++++++
src/bin/scripts/t/100_vacuumdb.pl | 10 ++++++-
src/bin/scripts/vacuumdb.c | 48 ++++++++++++++++++++++++++++++-
3 files changed, 72 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/ref/vacuumdb.sgml b/doc/src/sgml/ref/vacuumdb.sgml
index 47d93456f8..f6ac0c6e5a 100644
--- a/doc/src/sgml/ref/vacuumdb.sgml
+++ b/doc/src/sgml/ref/vacuumdb.sgml
@@ -226,6 +226,22 @@ PostgreSQL documentation
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>-P <replaceable class="parameter">workers</replaceable></option></term>
+ <term><option>--parallel=<replaceable class="parameter">workers</replaceable></option></term>
+ <listitem>
+ <para>
+ Execute parallel vacuum with <productname>PostgreSQL</productname>'s
+ <replaceable class="parameter">workers</replaceable> background workers.
+ </para>
+ <para>
+ This option will require background workers, so make sure your
+ <xref linkend="guc-max-parallel-workers-maintenance"/> setting is more
+ than one.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-q</option></term>
<term><option>--quiet</option></term>
diff --git a/src/bin/scripts/t/100_vacuumdb.pl b/src/bin/scripts/t/100_vacuumdb.pl
index b685b35282..8fe80719e8 100644
--- a/src/bin/scripts/t/100_vacuumdb.pl
+++ b/src/bin/scripts/t/100_vacuumdb.pl
@@ -3,7 +3,7 @@ use warnings;
use PostgresNode;
use TestLib;
-use Test::More tests => 44;
+use Test::More tests => 48;
program_help_ok('vacuumdb');
program_version_ok('vacuumdb');
@@ -48,6 +48,14 @@ $node->issues_sql_like(
$node->command_fails(
[ 'vacuumdb', '--analyze-only', '--disable-page-skipping', 'postgres' ],
'--analyze-only and --disable-page-skipping specified together');
+$node->issues_sql_like(
+ [ 'vacuumdb', '-P2', 'postgres' ],
+ qr/statement: VACUUM \(PARALLEL 2\).*;/,
+ 'vacuumdb -P2');
+$node->issues_sql_like(
+ [ 'vacuumdb', '-P', 'postgres' ],
+ qr/statement: VACUUM \(PARALLEL\).*;/,
+ 'vacuumdb -P');
$node->command_ok([qw(vacuumdb -Z --table=pg_am dbname=template1)],
'vacuumdb with connection string');
diff --git a/src/bin/scripts/vacuumdb.c b/src/bin/scripts/vacuumdb.c
index 2c7219239f..63bf66a70b 100644
--- a/src/bin/scripts/vacuumdb.c
+++ b/src/bin/scripts/vacuumdb.c
@@ -34,6 +34,8 @@ typedef struct vacuumingOptions
bool skip_locked;
int min_xid_age;
int min_mxid_age;
+ int parallel_workers; /* -1 disables, 0 for choosing based on the
+ * number of indexes */
} vacuumingOptions;
@@ -86,6 +88,7 @@ main(int argc, char *argv[])
{"full", no_argument, NULL, 'f'},
{"verbose", no_argument, NULL, 'v'},
{"jobs", required_argument, NULL, 'j'},
+ {"parallel", optional_argument, NULL, 'P'},
{"maintenance-db", required_argument, NULL, 2},
{"analyze-in-stages", no_argument, NULL, 3},
{"disable-page-skipping", no_argument, NULL, 4},
@@ -115,6 +118,7 @@ main(int argc, char *argv[])
/* initialize options to all false */
memset(&vacopts, 0, sizeof(vacopts));
+ vacopts.parallel_workers = -1;
pg_logging_init(argv[0]);
progname = get_progname(argv[0]);
@@ -122,7 +126,7 @@ main(int argc, char *argv[])
handle_help_version_opts(argc, argv, "vacuumdb", help);
- while ((c = getopt_long(argc, argv, "h:p:U:wWeqd:zZFat:fvj:", long_options, &optindex)) != -1)
+ while ((c = getopt_long(argc, argv, "h:p:P::U:wWeqd:zZFat:fvj:", long_options, &optindex)) != -1)
{
switch (c)
{
@@ -182,6 +186,24 @@ main(int argc, char *argv[])
exit(1);
}
break;
+ case 'P':
+ {
+ int parallel_workers = 0;
+
+ if (optarg != NULL)
+ {
+ parallel_workers = atoi(optarg);
+ if (parallel_workers <= 0)
+ {
+ pg_log_error("number of parallel workers must be at least 1");
+ exit(1);
+ }
+ }
+
+ /* allow to set 0, meaning PARALLEL without the parallel degree */
+ vacopts.parallel_workers = parallel_workers;
+ break;
+ }
case 2:
maintenance_db = pg_strdup(optarg);
break;
@@ -254,9 +276,22 @@ main(int argc, char *argv[])
"disable-page-skipping");
exit(1);
}
+ if (vacopts.parallel_workers >= 0)
+ {
+ pg_log_error("cannot use the \"%s\" option when performing only analyze",
+ "parallel");
+ exit(1);
+ }
/* allow 'and_analyze' with 'analyze_only' */
}
+ if (vacopts.full && vacopts.parallel_workers >= 0)
+ {
+ pg_log_error("cannot use the \"%s\" option with \"%s\" option",
+ "full", "parallel");
+ exit(1);
+ }
+
setup_cancel_handler();
/* Avoid opening extra connections. */
@@ -822,6 +857,16 @@ prepare_vacuum_command(PQExpBuffer sql, int serverVersion,
appendPQExpBuffer(sql, "%sANALYZE", sep);
sep = comma;
}
+ if (vacopts->parallel_workers > 0)
+ {
+ appendPQExpBuffer(sql, "%sPARALLEL %d", sep, vacopts->parallel_workers);
+ sep = comma;
+ }
+ if (vacopts->parallel_workers == 0)
+ {
+ appendPQExpBuffer(sql, "%sPARALLEL", sep);
+ sep = comma;
+ }
if (sep != paren)
appendPQExpBufferChar(sql, ')');
}
@@ -885,6 +930,7 @@ help(const char *progname)
printf(_(" -j, --jobs=NUM use this many concurrent connections to vacuum\n"));
printf(_(" --min-mxid-age=MXID_AGE minimum multixact ID age of tables to vacuum\n"));
printf(_(" --min-xid-age=XID_AGE minimum transaction ID age of tables to vacuum\n"));
+ printf(_(" -P, --parallel[=NUM] do parallel vacuuming\n"));
printf(_(" -q, --quiet don't write any messages\n"));
printf(_(" --skip-locked skip relations that cannot be immediately locked\n"));
printf(_(" -t, --table='TABLE[(COLUMNS)]' vacuum specific table(s) only\n"));
--
2.22.0
From 12a7a965a8dcb38ce79ba88afd20ea55fdeb5683 Mon Sep 17 00:00:00 2001
From: Masahiko Sawada <sawada.m...@gmail.com>
Date: Fri, 25 Oct 2019 22:47:41 +0900
Subject: [PATCH v32 2/4] Add parallel option to VACUUM command
This change adds PARALLEL option to VACUUM command that enable us to
perform index vacuuming and index cleanup with background
workers. Individual indexes is processed by one vacuum
process. Therefore parallel vacuum can be used when the table has at
least two indexes and it cannot specify larger parallel degree than
the number of indexes that the table has.
The parallel degree is either specified by user or determined based on
the number of indexes that the table has, and further limited by
max_parallel_maintenance_workers. The table size and index size don't
affect it.
---
doc/src/sgml/config.sgml | 14 +-
doc/src/sgml/ref/vacuum.sgml | 45 ++
src/backend/access/heap/vacuumlazy.c | 1048 ++++++++++++++++++++++---
src/backend/access/transam/parallel.c | 4 +
src/backend/commands/vacuum.c | 45 ++
src/backend/postmaster/autovacuum.c | 2 +
src/bin/psql/tab-complete.c | 2 +-
src/include/access/heapam.h | 3 +
src/include/commands/vacuum.h | 5 +
src/test/regress/expected/vacuum.out | 14 +
src/test/regress/sql/vacuum.sql | 10 +
11 files changed, 1084 insertions(+), 108 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 886632ff43..335a0ec752 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2265,13 +2265,13 @@ include_dir 'conf.d'
<listitem>
<para>
Sets the maximum number of parallel workers that can be
- started by a single utility command. Currently, the only
- parallel utility command that supports the use of parallel
- workers is <command>CREATE INDEX</command>, and only when
- building a B-tree index. Parallel workers are taken from the
- pool of processes established by <xref
- linkend="guc-max-worker-processes"/>, limited by <xref
- linkend="guc-max-parallel-workers"/>. Note that the requested
+ started by a single utility command. Currently, the parallel
+ utility commands that support the use of parallel workers are
+ <command>CREATE INDEX</command> only when building a B-tree index,
+ and <command>VACUUM</command> without <literal>FULL</literal>
+ option. Parallel workers are taken from the pool of processes
+ established by <xref linkend="guc-max-worker-processes"/>, limited
+ by <xref linkend="guc-max-parallel-workers"/>. Note that the requested
number of workers may not actually be available at run time.
If this occurs, the utility operation will run with fewer
workers than expected. The default value is 2. Setting this
diff --git a/doc/src/sgml/ref/vacuum.sgml b/doc/src/sgml/ref/vacuum.sgml
index f9b0fb8794..ae086b976b 100644
--- a/doc/src/sgml/ref/vacuum.sgml
+++ b/doc/src/sgml/ref/vacuum.sgml
@@ -34,6 +34,7 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet
SKIP_LOCKED [ <replaceable class="parameter">boolean</replaceable> ]
INDEX_CLEANUP [ <replaceable class="parameter">boolean</replaceable> ]
TRUNCATE [ <replaceable class="parameter">boolean</replaceable> ]
+ PARALLEL [ <replaceable class="parameter">integer</replaceable> ]
<phrase>and <replaceable class="parameter">table_and_columns</replaceable> is:</phrase>
@@ -223,6 +224,32 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>PARALLEL</literal></term>
+ <listitem>
+ <para>
+ Perform vacuum index and cleanup index phases of <command>VACUUM</command>
+ in parallel using <replaceable class="parameter">integer</replaceable>
+ background workers (for the detail of each vacuum phases, please
+ refer to <xref linkend="vacuum-phases"/>). If the parallel degree
+ <replaceable class="parameter">integer</replaceable> is omitted,
+ then <command>VACUUM</command> decides the number of workers based
+ on number of indexes that support parallel vacuum operation on the
+ relation which is further limited by
+ <xref linkend="guc-max-parallel-workers-maintenance"/>. Please note
+ that it is not guaranteed that the number of parallel worker specified
+ in <replaceable class="parameter">integer</replaceable> will be used
+ during execution. It is possible for a vacuum to run with fewer workers
+ than specified, or even with no workers at all. Only one worker can
+ be used per index. So parallel workers are launched only when there
+ are at least <literal>2</literal> indexes in the table. Workers for
+ vacuum launches before starting each phases and exit at the end of
+ the phase. These behaviors might change in a future release. This
+ option can not use with <literal>FULL</literal> option.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="parameter">boolean</replaceable></term>
<listitem>
@@ -237,6 +264,18 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><replaceable class="parameter">integer</replaceable></term>
+ <listitem>
+ <para>
+ Specifies a positive integer value passed to the selected option.
+ The <replaceable class="parameter">integer</replaceable> value can
+ also be omitted, in which case the default value of the selected
+ option is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="parameter">table_name</replaceable></term>
<listitem>
@@ -316,6 +355,12 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet
more than a plain <command>VACUUM</command> would.
</para>
+ <para>
+ The <option>PARALLEL</option> option is used for only vacuum purpose.
+ Even if this option is specified with <option>ANALYZE</option> option
+ it does not affect <option>ANALYZE</option>.
+ </para>
+
<para>
<command>VACUUM</command> causes a substantial increase in I/O traffic,
which might cause poor performance for other active sessions. Therefore,
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index a3c4a1df3b..0cfa13b81b 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -22,6 +22,21 @@
* of index scans performed. So we don't use maintenance_work_mem memory for
* the TID array, just enough to hold as many heap tuples as fit on one page.
*
+ * Lazy vacuum supports parallel execution with parallel worker processes. In
+ * parallel lazy vacuum, we perform both index vacuuming and index cleanup with
+ * parallel worker processes. Individual indexes are processed by one vacuum
+ * process. At the beginning of lazy vacuum (at lazy_scan_heap) we prepare the
+ * parallel context and initialize the DSM segment that contains shared information
+ * as well as the memory space for storing dead tuples. When starting either
+ * index vacuuming or index cleanup, we launch parallel worker processes. Once
+ * all indexes are processed the parallel worker processes exit. And then the
+ * leader process re-initializes the parallel context while keeping recorded
+ * dead tuples so that the leader can launch parallel workers again in the next
+ * time. Note that all parallel workers live during either index vacuuming or
+ * index cleanup but the leader process neither exits from the parallel mode
+ * nor destroys the parallel context. For updating the index statistics, since
+ * any updates are not allowed during parallel mode we update the index
+ * statistics after exited from the parallel mode.
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
@@ -36,13 +51,16 @@
#include <math.h>
+#include "access/amapi.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/heapam_xlog.h"
#include "access/htup_details.h"
#include "access/multixact.h"
+#include "access/parallel.h"
#include "access/transam.h"
#include "access/visibilitymap.h"
+#include "access/xact.h"
#include "access/xlog.h"
#include "catalog/storage.h"
#include "commands/dbcommands.h"
@@ -55,6 +73,7 @@
#include "storage/bufmgr.h"
#include "storage/freespace.h"
#include "storage/lmgr.h"
+#include "tcop/tcopprot.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/pg_rusage.h"
@@ -110,6 +129,139 @@
*/
#define PREFETCH_SIZE ((BlockNumber) 32)
+/*
+ * DSM keys for parallel lazy vacuum. Unlike other parallel execution code,
+ * since we don't need to worry about DSM keys conflicting with plan_node_id
+ * we can use small integers.
+ */
+#define PARALLEL_VACUUM_KEY_SHARED 1
+#define PARALLEL_VACUUM_KEY_DEAD_TUPLES 2
+#define PARALLEL_VACUUM_KEY_QUERY_TEXT 3
+
+/*
+ * PARALLEL_VACUUM_DISABLE_LEADER_PARTICIPATION disables the leader's
+ * participation in parallel lazy vacuum. This may be useful as a debugging
+ * aid.
+#undef PARALLEL_VACUUM_DISABLE_LEADER_PARTICIPATION
+ */
+
+/*
+ * Macro to check if we are in a parallel lazy vacuum. If true, we are
+ * in the parallel mode and prepared the DSM segment.
+ */
+#define ParallelVacuumIsActive(lps) (((LVParallelState *) (lps)) != NULL)
+
+/*
+ * LVDeadTuples stores the dead tuple TIDs collected during heap scan.
+ * This is allocated in the DSM segment when parallel lazy vacuum
+ * mode, otherwise allocated in a local memory.
+ */
+typedef struct LVDeadTuples
+{
+ int max_tuples; /* # slots allocated in array */
+ int num_tuples; /* current # of entries */
+ /* List of TIDs of tuples we intend to delete */
+ /* NB: this list is ordered by TID address */
+ ItemPointerData itemptrs[FLEXIBLE_ARRAY_MEMBER]; /* array of ItemPointerData */
+} LVDeadTuples;
+#define SizeOfLVDeadTuples offsetof(LVDeadTuples, itemptrs) + sizeof(ItemPointerData)
+
+/*
+ * Shared information among parallel workers. So this is allocated in
+ * the DSM segment.
+ */
+typedef struct LVShared
+{
+ /*
+ * Target table relid and log level. These fields are not modified
+ * during the lazy vacuum.
+ */
+ Oid relid;
+ int elevel;
+
+ /*
+ * An indication for vacuum workers of doing either index vacuuming or
+ * index cleanup.
+ */
+ bool for_cleanup;
+
+ /*
+ * Fields for both index vacuuming and index cleanup.
+ *
+ * reltuples is the total number of input heap tuples. We set either
+ * an old live tuples in index vacuuming case or the new live tuples in
+ * index cleanup case.
+ *
+ * estimated_count is true if the reltuples is estimated value.
+ */
+ double reltuples;
+ bool estimated_count;
+
+
+ /*
+ * In single process lazy vacuum we could consume more memory during
+ * index vacuuming or cleanup apart from the memory for heap scanning
+ * if an index consume memory during ambulkdelete and amvacuumcleanup.
+ * In parallel index vacuuming, since individual vacuum workers
+ * consumes memory we set the new maitenance_work_mem for each workers
+ * to not consume more memory than single process lazy vacuum.
+ */
+ int maintenance_work_mem_worker;
+
+ /* The number of indexes that do NOT support parallel index vacuuming */
+ int nindexes_nonparallel;
+
+ /*
+ * Variables to control parallel index vacuuming. Index statistics
+ * returned from ambulkdelete and amvacuumcleanup is nullable variable
+ * length. 'offset' is NULL bitmap. Note that a 0 indicates a null,
+ * while 1 indicates non-null. The index statistics follows at end of
+ * struct.
+ */
+ pg_atomic_uint32 nprocessed; /* counter for vacuuming and clean up */
+ uint32 offset; /* sizeof header incl. bitmap */
+ bits8 bitmap[FLEXIBLE_ARRAY_MEMBER]; /* bit map of NULLs */
+
+ /* Shared index statistics data follows at end of struct */
+} LVShared;
+#define SizeOfLVShared offsetof(LVShared, bitmap) + sizeof(bits8)
+#define GetSharedIndStats(s) \
+ ((LVSharedIndStats *)((char *)(s) + ((LVShared *)(s))->offset))
+#define IndStatsIsNull(s, i) \
+ (!(((LVShared *)(s))->bitmap[(i) >> 3] & (1 << ((i) & 0x07))))
+
+/*
+ * Struct for an index bulk-deletion statistic used for parallel lazy
+ * vacuum. This is allocated in the DSM segment. IndexBulkDeleteResult
+ * follows at end of struct.
+ */
+typedef struct LVSharedIndStats
+{
+ Size size;
+ bool updated; /* are the stats updated */
+
+ /* Index bulk-deletion result data follows at end of struct */
+} LVSharedIndStats;
+#define SizeOfSharedIndStats(s) \
+ (sizeof(LVSharedIndStats) + ((LVSharedIndStats *)(s))->size)
+#define GetIndexBulkDeleteResult(s) \
+ ((IndexBulkDeleteResult *)((char *)(s) + sizeof(LVSharedIndStats)))
+
+/* Struct for parallel lazy vacuum */
+typedef struct LVParallelState
+{
+ ParallelContext *pcxt;
+
+ /* Shared information among parallel vacuum workers */
+ LVShared *lvshared;
+
+ /*
+ * Always true except for a debugging case where
+ * PARALLEL_VACUUM_DISABLE_LEADER_PARTICIPATION are defined.
+ */
+ bool leaderparticipates;
+} LVParallelState;
+
typedef struct LVRelStats
{
/* useindex = true means two-pass strategy; false means one-pass */
@@ -128,11 +280,7 @@ typedef struct LVRelStats
BlockNumber pages_removed;
double tuples_deleted;
BlockNumber nonempty_pages; /* actually, last nonempty page + 1 */
- /* List of TIDs of tuples we intend to delete */
- /* NB: this list is ordered by TID address */
- int num_dead_tuples; /* current # of entries */
- int max_dead_tuples; /* # slots allocated in array */
- ItemPointer dead_tuples; /* array of ItemPointerData */
+ LVDeadTuples *dead_tuples;
int num_index_scans;
TransactionId latestRemovedXid;
bool lock_waiter_detected;
@@ -155,12 +303,11 @@ static void lazy_scan_heap(Relation onerel, VacuumParams *params,
bool aggressive);
static void lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats);
static bool lazy_check_needs_freeze(Buffer buf, bool *hastup);
-static void lazy_vacuum_index(Relation indrel,
- IndexBulkDeleteResult **stats,
- LVRelStats *vacrelstats);
+static void lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
+ LVDeadTuples *dead_tuples, double reltuples);
static void lazy_cleanup_index(Relation indrel,
- IndexBulkDeleteResult *stats,
- LVRelStats *vacrelstats);
+ IndexBulkDeleteResult **stats,
+ double reltuples, bool estimated_count);
static int lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
int tupindex, LVRelStats *vacrelstats, Buffer *vmbuffer);
static bool should_attempt_truncation(VacuumParams *params,
@@ -169,12 +316,36 @@ static void lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats);
static BlockNumber count_nondeletable_pages(Relation onerel,
LVRelStats *vacrelstats);
static void lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks);
-static void lazy_record_dead_tuple(LVRelStats *vacrelstats,
+static void lazy_record_dead_tuple(LVDeadTuples *dead_tuples,
ItemPointer itemptr);
static bool lazy_tid_reaped(ItemPointer itemptr, void *state);
static int vac_cmp_itemptr(const void *left, const void *right);
static bool heap_page_is_all_visible(Relation rel, Buffer buf,
TransactionId *visibility_cutoff_xid, bool *all_frozen);
+static LVParallelState *begin_parallel_vacuum(LVRelStats *vacrelstats, Oid relid,
+ BlockNumber nblocks, Relation *Irel,
+ int nindexes, int nrequested);
+static void end_parallel_vacuum(LVParallelState *lps, Relation *Irel, int nindexes,
+ IndexBulkDeleteResult **stats);
+static void prepare_index_statistics(LVShared *lvshared, Relation *Irel, int nindexes);
+static void lazy_vacuum_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps);
+static void lazy_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps);
+static void lazy_parallel_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps);
+static void vacuum_or_cleanup_indexes_worker(Relation *Irel, int nindexes,
+ IndexBulkDeleteResult **stats,
+ LVShared *lvshared,
+ LVDeadTuples *dead_tuples);
+static void update_index_statistics(Relation *Irel, IndexBulkDeleteResult **stats,
+ int nindexes);
+static LVSharedIndStats *get_indstats(LVShared *lvshared, int n);
+static int compute_parallel_workers(Relation *Irel, int nindexes, int nrequested);
+static long compute_max_dead_tuples(BlockNumber relblocks, bool hasindex);
/*
@@ -488,6 +659,18 @@ vacuum_log_cleanup_info(Relation rel, LVRelStats *vacrelstats)
* dead-tuple TIDs, invoke vacuuming of indexes and call lazy_vacuum_heap
* to reclaim dead line pointers.
*
+ * If the table has at least two indexes and parallel lazy vacuum is
+ * requested, we execute both index vacuuming and index cleanup with
+ * parallel workers. In parallel lazy vacuum, we enter parallel mode and
+ * then create both the parallel context and the DSM segment before starting
+ * heap scan so that we can record dead tuples to the DSM segment. All
+ * parallel workers are launched at beginning of index vacuuming and index
+ * cleanup and they exit once done with all indexes. At the end of this
+ * function we exit from parallel mode. Index bulk-deletion results are
+ * stored in the DSM segment and update index statistics as a whole after
+ * exited from parallel mode since all writes are not allowed during parallel
+ * mode.
+ *
* If there are no indexes then we can reclaim line pointers on the fly;
* dead line pointers need only be retained until all index pointers that
* reference them have been killed.
@@ -496,6 +679,8 @@ static void
lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
Relation *Irel, int nindexes, bool aggressive)
{
+ LVParallelState *lps = NULL;
+ LVDeadTuples *dead_tuples;
BlockNumber nblocks,
blkno;
HeapTupleData tuple;
@@ -518,6 +703,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
bool skipping_blocks;
xl_heap_freeze_tuple *frozen;
StringInfoData buf;
+ int parallel_workers = 0;
const int initprog_index[] = {
PROGRESS_VACUUM_PHASE,
PROGRESS_VACUUM_TOTAL_HEAP_BLKS,
@@ -553,13 +739,41 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
vacrelstats->nonempty_pages = 0;
vacrelstats->latestRemovedXid = InvalidTransactionId;
- lazy_space_alloc(vacrelstats, nblocks);
+ /*
+ * If parallel lazy vacuum is requested and we vacuum indexes, compute
+ * the number of parallel vacuum worker to launch.
+ */
+ if (params->nworkers >= 0 && vacrelstats->useindex)
+ parallel_workers = compute_parallel_workers(Irel, nindexes,
+ params->nworkers);
+
+ if (parallel_workers > 0)
+ {
+ /*
+ * Enter parallel mode, create the parallel context and allocate the
+ * DSM segment.
+ */
+ lps = begin_parallel_vacuum(vacrelstats,
+ RelationGetRelid(onerel),
+ nblocks, Irel, nindexes,
+ parallel_workers);
+ }
+ else
+ {
+ /*
+ * Use single process vacuum. We allocate the memory space for dead
+ * tuples locally.
+ */
+ lazy_space_alloc(vacrelstats, nblocks);
+ }
+
+ dead_tuples = vacrelstats->dead_tuples;
frozen = palloc(sizeof(xl_heap_freeze_tuple) * MaxHeapTuplesPerPage);
/* Report that we're scanning the heap, advertising total # of blocks */
initprog_val[0] = PROGRESS_VACUUM_PHASE_SCAN_HEAP;
initprog_val[1] = nblocks;
- initprog_val[2] = vacrelstats->max_dead_tuples;
+ initprog_val[2] = dead_tuples->max_tuples;
pgstat_progress_update_multi_param(3, initprog_index, initprog_val);
/*
@@ -737,8 +951,8 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
* If we are close to overrunning the available space for dead-tuple
* TIDs, pause and do a cycle of vacuuming before we tackle this page.
*/
- if ((vacrelstats->max_dead_tuples - vacrelstats->num_dead_tuples) < MaxHeapTuplesPerPage &&
- vacrelstats->num_dead_tuples > 0)
+ if ((dead_tuples->max_tuples - dead_tuples->num_tuples) < MaxHeapTuplesPerPage &&
+ dead_tuples->num_tuples > 0)
{
const int hvp_index[] = {
PROGRESS_VACUUM_PHASE,
@@ -766,10 +980,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
PROGRESS_VACUUM_PHASE_VACUUM_INDEX);
/* Remove index entries */
- for (i = 0; i < nindexes; i++)
- lazy_vacuum_index(Irel[i],
- &indstats[i],
- vacrelstats);
+ lazy_vacuum_indexes(vacrelstats, Irel, nindexes, indstats, lps);
/*
* Report that we are now vacuuming the heap. We also increase
@@ -789,7 +1000,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
* not to reset latestRemovedXid since we want that value to be
* valid.
*/
- vacrelstats->num_dead_tuples = 0;
+ dead_tuples->num_tuples = 0;
vacrelstats->num_index_scans++;
/*
@@ -985,7 +1196,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
has_dead_tuples = false;
nfrozen = 0;
hastup = false;
- prev_dead_count = vacrelstats->num_dead_tuples;
+ prev_dead_count = dead_tuples->num_tuples;
maxoff = PageGetMaxOffsetNumber(page);
/*
@@ -1024,7 +1235,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
*/
if (ItemIdIsDead(itemid))
{
- lazy_record_dead_tuple(vacrelstats, &(tuple.t_self));
+ lazy_record_dead_tuple(dead_tuples, &(tuple.t_self));
all_visible = false;
continue;
}
@@ -1170,7 +1381,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
if (tupgone)
{
- lazy_record_dead_tuple(vacrelstats, &(tuple.t_self));
+ lazy_record_dead_tuple(dead_tuples, &(tuple.t_self));
HeapTupleHeaderAdvanceLatestRemovedXid(tuple.t_data,
&vacrelstats->latestRemovedXid);
tups_vacuumed += 1;
@@ -1240,7 +1451,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
* doing a second scan. Also we don't do that but forget dead tuples
* when index cleanup is disabled.
*/
- if (!vacrelstats->useindex && vacrelstats->num_dead_tuples > 0)
+ if (!vacrelstats->useindex && dead_tuples->num_tuples > 0)
{
if (nindexes == 0)
{
@@ -1269,7 +1480,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
* not to reset latestRemovedXid since we want that value to be
* valid.
*/
- vacrelstats->num_dead_tuples = 0;
+ dead_tuples->num_tuples = 0;
/*
* Periodically do incremental FSM vacuuming to make newly-freed
@@ -1384,7 +1595,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
* page, so remember its free space as-is. (This path will always be
* taken if there are no indexes.)
*/
- if (vacrelstats->num_dead_tuples == prev_dead_count)
+ if (dead_tuples->num_tuples == prev_dead_count)
RecordPageWithFreeSpace(onerel, blkno, freespace);
}
@@ -1418,7 +1629,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
/* If any tuples need to be deleted, perform final vacuum cycle */
/* XXX put a threshold on min number of tuples here? */
- if (vacrelstats->num_dead_tuples > 0)
+ if (dead_tuples->num_tuples > 0)
{
const int hvp_index[] = {
PROGRESS_VACUUM_PHASE,
@@ -1434,10 +1645,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
PROGRESS_VACUUM_PHASE_VACUUM_INDEX);
/* Remove index entries */
- for (i = 0; i < nindexes; i++)
- lazy_vacuum_index(Irel[i],
- &indstats[i],
- vacrelstats);
+ lazy_vacuum_indexes(vacrelstats, Irel, nindexes, indstats, lps);
/* Report that we are now vacuuming the heap */
hvp_val[0] = PROGRESS_VACUUM_PHASE_VACUUM_HEAP;
@@ -1463,12 +1671,19 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
PROGRESS_VACUUM_PHASE_INDEX_CLEANUP);
- /* Do post-vacuum cleanup and statistics update for each index */
+ /* Do post-vacuum cleanup */
if (vacrelstats->useindex)
- {
- for (i = 0; i < nindexes; i++)
- lazy_cleanup_index(Irel[i], indstats[i], vacrelstats);
- }
+ lazy_cleanup_indexes(vacrelstats, Irel, nindexes, indstats, lps);
+
+ /*
+ * End parallel mode before updating index statistics as we cannot write
+ * during parallel mode.
+ */
+ if (ParallelVacuumIsActive(lps))
+ end_parallel_vacuum(lps, Irel, nindexes, indstats);
+
+ /* Update index statistics */
+ update_index_statistics(Irel, indstats, nindexes);
/* If no indexes, make log report that lazy_vacuum_heap would've made */
if (vacuumed_pages)
@@ -1534,7 +1749,7 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
npages = 0;
tupindex = 0;
- while (tupindex < vacrelstats->num_dead_tuples)
+ while (tupindex < vacrelstats->dead_tuples->num_tuples)
{
BlockNumber tblk;
Buffer buf;
@@ -1543,7 +1758,7 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
vacuum_delay_point();
- tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples[tupindex]);
+ tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples->itemptrs[tupindex]);
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, tblk, RBM_NORMAL,
vac_strategy);
if (!ConditionalLockBufferForCleanup(buf))
@@ -1591,6 +1806,7 @@ static int
lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
int tupindex, LVRelStats *vacrelstats, Buffer *vmbuffer)
{
+ LVDeadTuples *dead_tuples = vacrelstats->dead_tuples;
Page page = BufferGetPage(buffer);
OffsetNumber unused[MaxOffsetNumber];
int uncnt = 0;
@@ -1601,16 +1817,16 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
START_CRIT_SECTION();
- for (; tupindex < vacrelstats->num_dead_tuples; tupindex++)
+ for (; tupindex < dead_tuples->num_tuples; tupindex++)
{
BlockNumber tblk;
OffsetNumber toff;
ItemId itemid;
- tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples[tupindex]);
+ tblk = ItemPointerGetBlockNumber(&dead_tuples->itemptrs[tupindex]);
if (tblk != blkno)
break; /* past end of tuples for this block */
- toff = ItemPointerGetOffsetNumber(&vacrelstats->dead_tuples[tupindex]);
+ toff = ItemPointerGetOffsetNumber(&dead_tuples->itemptrs[tupindex]);
itemid = PageGetItemId(page, toff);
ItemIdSetUnused(itemid);
unused[uncnt++] = toff;
@@ -1731,19 +1947,290 @@ lazy_check_needs_freeze(Buffer buf, bool *hastup)
return false;
}
+/*
+ * Perform index vacuuming or index cleanup with parallel workers. This function
+ * must be used by the parallel vacuum leader process. The caller must set
+ * lps->lvshared->for_cleanup to indicate whether vacuuming or cleanup.
+ */
+static void
+lazy_parallel_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps)
+{
+ Assert(!IsParallelWorker());
+ Assert(ParallelVacuumIsActive(lps));
+ Assert(nindexes > 0);
+
+ LaunchParallelWorkers(lps->pcxt);
+
+ if (lps->lvshared->for_cleanup)
+ ereport(elevel,
+ (errmsg(ngettext("launched %d parallel vacuum worker for index vacuuming (planned: %d)",
+ "launched %d parallel vacuum workers for index vacuuming (planned: %d)",
+ lps->pcxt->nworkers_launched),
+ lps->pcxt->nworkers_launched, lps->pcxt->nworkers)));
+ else
+ ereport(elevel,
+ (errmsg(ngettext("launched %d parallel vacuum worker for index cleanup (planned: %d)",
+ "launched %d parallel vacuum workers for index cleanup (planned: %d)",
+ lps->pcxt->nworkers_launched),
+ lps->pcxt->nworkers_launched, lps->pcxt->nworkers)));
+
+ /*
+ * Join as parallel workers. The leader process alone does that in case where
+ * no workers launched.
+ */
+ if (lps->leaderparticipates || lps->pcxt->nworkers_launched == 0)
+ vacuum_or_cleanup_indexes_worker(Irel, nindexes, stats, lps->lvshared,
+ vacrelstats->dead_tuples);
+
+ /* Wait for all vacuum workers to finish */
+ WaitForParallelWorkersToFinish(lps->pcxt);
+
+ /*
+ * We need to reinitialize the parallel context as no more index vacuuming and
+ * index cleanup will be performed after that.
+ */
+ if (!lps->lvshared->for_cleanup)
+ {
+ /* Reset the processing count */
+ pg_atomic_write_u32(&(lps->lvshared->nprocessed), 0);
+
+ /*
+ * Reinitialize the parallel context to relaunch parallel workers
+ * for the next execution.
+ */
+ ReinitializeParallelDSM(lps->pcxt);
+ }
+}
+
+/*
+ * Index vacuuming and index cleanup routine used by parallel vacuum
+ * worker processes including the leader process. After finished each
+ * indexes this function copies the index statistics returned from
+ * ambulkdelete and amvacuumcleanup to the DSM segment.
+ */
+static void
+vacuum_or_cleanup_indexes_worker(Relation *Irel, int nindexes,
+ IndexBulkDeleteResult **stats,
+ LVShared *lvshared,
+ LVDeadTuples *dead_tuples)
+{
+ /* Loop until all indexes are vacuumed */
+ for (;;)
+ {
+ int idx;
+ LVSharedIndStats *shared_indstats;
+ IndexBulkDeleteResult *bulkdelete_res;
+
+ /* Get an index number to process */
+ idx = pg_atomic_fetch_add_u32(&(lvshared->nprocessed), 1);
+
+ /* Done for all indexes? */
+ if (idx >= nindexes)
+ break;
+
+ /* Get index statistics struct of this index */
+ shared_indstats = get_indstats(lvshared, idx);
+
+ /* Skip if this index doesn't support parallel index vacuuming */
+ if (shared_indstats == NULL)
+ continue;
+
+ /* Get the space for IndexBulkDeleteResult */
+ bulkdelete_res = GetIndexBulkDeleteResult(shared_indstats);
+
+ /*
+ * Update the pointer to the corresponding bulk-deletion result
+ * if someone has already updated it.
+ */
+ if (shared_indstats->updated && stats[idx] == NULL)
+ stats[idx] = bulkdelete_res;
+
+ /* Do vacuum or cleanup one index */
+ if (lvshared->for_cleanup)
+ lazy_cleanup_index(Irel[idx], &(stats[idx]), lvshared->reltuples,
+ lvshared->estimated_count);
+ else
+ lazy_vacuum_index(Irel[idx], &(stats[idx]), dead_tuples,
+ lvshared->reltuples);
+
+ /*
+ * Copy the index bulk-deletion result returned from ambulkdelete
+ * and amvacuumcleanup to the DSM segment if it's the first time to
+ * get it from them, because they allocate it locally and it's
+ * possible that an index will be vacuumed by the different vacuum
+ * process at the next time. The copying the result normally
+ * happens only after the first time of index vacuuming. From the
+ * second time, we pass the result on the DSM segment so that they
+ * then update it directly.
+ *
+ * Since all vacuum workers write the bulk-deletion result at
+ * different slots we can write them without locking.
+ */
+ if (!shared_indstats->updated && stats[idx] != NULL)
+ {
+ memcpy(bulkdelete_res, stats[idx], shared_indstats->size);
+ shared_indstats->updated = true;
+
+ /*
+ * no longer need the locally allocated result and now
+ * stats[idx] points to the DSM segment.
+ */
+ pfree(stats[idx]);
+ stats[idx] = bulkdelete_res;
+ }
+ }
+}
+
+/*
+ * Cleanup indexes. This function must be used by the parallel vacuum
+ * leader process in parallel vacuum case.
+ */
+static void
+lazy_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps)
+{
+ int idx;
+
+ Assert(!IsParallelWorker());
+ Assert(nindexes > 0);
+
+ /*
+ * If parallel vacuum is active we perform index cleanup with parallel
+ * workers.
+ */
+ if (ParallelVacuumIsActive(lps))
+ {
+ /* Tell parallel workers to do index cleanup */
+ lps->lvshared->for_cleanup = true;
+
+ /*
+ * Now we can provide a better estimate of total number of
+ * surviving tuples (we assume indexes are more interested in that
+ * than in the number of nominally live tuples).
+ */
+ lps->lvshared->reltuples = vacrelstats->new_rel_tuples;
+ lps->lvshared->estimated_count =
+ (vacrelstats->tupcount_pages < vacrelstats->rel_pages);
+
+ /*
+ * Generally index cleanup does not scan the index when index
+ * vacuuming (ambulkdelete) was already performed. So we perform
+ * index cleanup with parallel workers only if we have not
+ * performed index vacuuming yet. Otherwise, we do it in the
+ * leader process alone.
+ */
+ if (vacrelstats->num_index_scans == 0)
+ lazy_parallel_vacuum_or_cleanup_indexes(vacrelstats, Irel, nindexes,
+ stats, lps);
+ else
+ {
+ /*
+ * Do cleanup by the leader process alone. Since we need to
+ * copy the index statistics to the DSM segment we cannot use
+ * lazy_index_cleanup instead.
+ */
+ vacuum_or_cleanup_indexes_worker(Irel, nindexes, stats,
+ lps->lvshared,
+ vacrelstats->dead_tuples);
+ }
+
+ /*
+ * Done if there is no indexes that do not support parallel index
+ * vacuuming. Otherwise fall through to do single process vacuum
+ * on such indexes.
+ */
+ if (lps->lvshared->nindexes_nonparallel == 0)
+ return;
+ }
+
+ for (idx = 0; idx < nindexes; idx++)
+ {
+ /*
+ * Skip indexes that we have already cleaned up during parallel
+ * index vacuuming.
+ */
+ if (ParallelVacuumIsActive(lps) && !IndStatsIsNull(lps->lvshared,idx))
+ continue;
+
+ lazy_cleanup_index(Irel[idx], &stats[idx],
+ vacrelstats->new_rel_tuples,
+ vacrelstats->tupcount_pages < vacrelstats->rel_pages);
+ }
+}
+
+/*
+ * Vacuum indexes. This function must be used by the parallel vacuum leader
+ * process in parallel vacuum case.
+ */
+static void
+lazy_vacuum_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps)
+{
+ int idx;
+
+ Assert(!IsParallelWorker());
+ Assert(nindexes > 0);
+
+ /*
+ * If parallel vacuum is active we perform index vacuuming with
+ * parallel workers.
+ */
+ if (ParallelVacuumIsActive(lps))
+ {
+ /* Tell parallel workers to do index vacuuming */
+ lps->lvshared->for_cleanup = false;
+
+ /*
+ * We can only provide an approximate value of num_heap_tuples in
+ * vacuum cases.
+ */
+ lps->lvshared->reltuples = vacrelstats->old_live_tuples;
+ lps->lvshared->estimated_count = true;
+
+ lazy_parallel_vacuum_or_cleanup_indexes(vacrelstats, Irel, nindexes,
+ stats, lps);
+
+ /*
+ * Done if there is no indexes that do not support parallel index
+ * vacuuming. Otherwise fall through to do single process vacuum
+ * on such indexes.
+ */
+ if (lps->lvshared->nindexes_nonparallel == 0)
+ return;
+ }
+
+ for (idx = 0; idx < nindexes; idx++)
+ {
+ /*
+ * Skip indexes that we have already vacuumed during parallel index
+ * vacuuming.
+ */
+ if (ParallelVacuumIsActive(lps) && !IndStatsIsNull(lps->lvshared, idx))
+ continue;
+
+ lazy_vacuum_index(Irel[idx], &stats[idx], vacrelstats->dead_tuples,
+ vacrelstats->old_live_tuples);
+ }
+}
/*
* lazy_vacuum_index() -- vacuum one index relation.
*
* Delete all the index entries pointing to tuples listed in
* vacrelstats->dead_tuples, and update running statistics.
+ * reltuples is the number of heap tuples to be passed to the
+ * bulk delete callback.
*/
static void
-lazy_vacuum_index(Relation indrel,
- IndexBulkDeleteResult **stats,
- LVRelStats *vacrelstats)
+lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
+ LVDeadTuples *dead_tuples, double reltuples)
{
IndexVacuumInfo ivinfo;
+ char *msgfmt;
PGRUsage ru0;
pg_rusage_init(&ru0);
@@ -1753,30 +2240,38 @@ lazy_vacuum_index(Relation indrel,
ivinfo.report_progress = false;
ivinfo.estimated_count = true;
ivinfo.message_level = elevel;
- /* We can only provide an approximate value of num_heap_tuples here */
- ivinfo.num_heap_tuples = vacrelstats->old_live_tuples;
+ ivinfo.num_heap_tuples = reltuples;
ivinfo.strategy = vac_strategy;
/* Do bulk deletion */
*stats = index_bulk_delete(&ivinfo, *stats,
- lazy_tid_reaped, (void *) vacrelstats);
+ lazy_tid_reaped, (void *) dead_tuples);
+
+ if (IsParallelWorker())
+ msgfmt = gettext_noop("scanned index \"%s\" to remove %d row versions by parallel vacuum worker");
+ else
+ msgfmt = gettext_noop("scanned index \"%s\" to remove %d row versions");
ereport(elevel,
- (errmsg("scanned index \"%s\" to remove %d row versions",
+ (errmsg(msgfmt,
RelationGetRelationName(indrel),
- vacrelstats->num_dead_tuples),
+ dead_tuples->num_tuples),
errdetail_internal("%s", pg_rusage_show(&ru0))));
}
/*
* lazy_cleanup_index() -- do post-vacuum cleanup for one index relation.
+ *
+ * reltuples is the number of heap tuples and estimated_count is true
+ * if the reltuples is an estimated value.
*/
static void
lazy_cleanup_index(Relation indrel,
- IndexBulkDeleteResult *stats,
- LVRelStats *vacrelstats)
+ IndexBulkDeleteResult **stats,
+ double reltuples, bool estimated_count)
{
IndexVacuumInfo ivinfo;
+ char *msgfmt;
PGRUsage ru0;
pg_rusage_init(&ru0);
@@ -1784,49 +2279,62 @@ lazy_cleanup_index(Relation indrel,
ivinfo.index = indrel;
ivinfo.analyze_only = false;
ivinfo.report_progress = false;
- ivinfo.estimated_count = (vacrelstats->tupcount_pages < vacrelstats->rel_pages);
+ ivinfo.estimated_count = estimated_count;
ivinfo.message_level = elevel;
- /*
- * Now we can provide a better estimate of total number of surviving
- * tuples (we assume indexes are more interested in that than in the
- * number of nominally live tuples).
- */
- ivinfo.num_heap_tuples = vacrelstats->new_rel_tuples;
+ ivinfo.num_heap_tuples = reltuples;
ivinfo.strategy = vac_strategy;
- stats = index_vacuum_cleanup(&ivinfo, stats);
+ *stats = index_vacuum_cleanup(&ivinfo, *stats);
- if (!stats)
+ if (!(*stats))
return;
- /*
- * Now update statistics in pg_class, but only if the index says the count
- * is accurate.
- */
- if (!stats->estimated_count)
- vac_update_relstats(indrel,
- stats->num_pages,
- stats->num_index_tuples,
- 0,
- false,
- InvalidTransactionId,
- InvalidMultiXactId,
- false);
+ if (IsParallelWorker())
+ msgfmt = gettext_noop("index \"%s\" now contains %.0f row versions in %u pages, reported by parallel vacuum worker");
+ else
+ msgfmt = gettext_noop("index \"%s\" now contains %.0f row versions in %u pages");
ereport(elevel,
- (errmsg("index \"%s\" now contains %.0f row versions in %u pages",
+ (errmsg(msgfmt,
RelationGetRelationName(indrel),
- stats->num_index_tuples,
- stats->num_pages),
+ (*stats)->num_index_tuples,
+ (*stats)->num_pages),
errdetail("%.0f index row versions were removed.\n"
"%u index pages have been deleted, %u are currently reusable.\n"
"%s.",
- stats->tuples_removed,
- stats->pages_deleted, stats->pages_free,
+ (*stats)->tuples_removed,
+ (*stats)->pages_deleted, (*stats)->pages_free,
pg_rusage_show(&ru0))));
+}
+
+/*
+ * Update index statistics in pg_class if the statistics is accurate.
+ */
+static void
+update_index_statistics(Relation *Irel, IndexBulkDeleteResult **stats,
+ int nindexes)
+{
+ int i;
+
+ Assert(!IsInParallelMode());
- pfree(stats);
+ for (i = 0; i < nindexes; i++)
+ {
+ if (stats[i] == NULL || stats[i]->estimated_count)
+ continue;
+
+ /* Update index statistics */
+ vac_update_relstats(Irel[i],
+ stats[i]->num_pages,
+ stats[i]->num_index_tuples,
+ 0,
+ false,
+ InvalidTransactionId,
+ InvalidMultiXactId,
+ false);
+ pfree(stats[i]);
+ }
}
/*
@@ -2134,19 +2642,17 @@ count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats)
}
/*
- * lazy_space_alloc - space allocation decisions for lazy vacuum
- *
- * See the comments at the head of this file for rationale.
+ * Return the maximum number of dead tuples we can record.
*/
-static void
-lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
+static long
+compute_max_dead_tuples(BlockNumber relblocks, bool useindex)
{
long maxtuples;
int vac_work_mem = IsAutoVacuumWorkerProcess() &&
autovacuum_work_mem != -1 ?
autovacuum_work_mem : maintenance_work_mem;
- if (vacrelstats->useindex)
+ if (useindex)
{
maxtuples = (vac_work_mem * 1024L) / sizeof(ItemPointerData);
maxtuples = Min(maxtuples, INT_MAX);
@@ -2160,34 +2666,49 @@ lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
maxtuples = Max(maxtuples, MaxHeapTuplesPerPage);
}
else
- {
maxtuples = MaxHeapTuplesPerPage;
- }
- vacrelstats->num_dead_tuples = 0;
- vacrelstats->max_dead_tuples = (int) maxtuples;
- vacrelstats->dead_tuples = (ItemPointer)
- palloc(maxtuples * sizeof(ItemPointerData));
+ return maxtuples;
+}
+
+/*
+ * lazy_space_alloc - space allocation decisions for lazy vacuum
+ *
+ * See the comments at the head of this file for rationale.
+ */
+static void
+lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
+{
+ LVDeadTuples *dead_tuples = NULL;
+ long maxtuples;
+
+ maxtuples = compute_max_dead_tuples(relblocks, vacrelstats->useindex);
+
+ dead_tuples = (LVDeadTuples *)
+ palloc(SizeOfLVDeadTuples + maxtuples * sizeof(ItemPointerData));
+ dead_tuples->num_tuples = 0;
+ dead_tuples->max_tuples = (int) maxtuples;
+
+ vacrelstats->dead_tuples = dead_tuples;
}
/*
* lazy_record_dead_tuple - remember one deletable tuple
*/
static void
-lazy_record_dead_tuple(LVRelStats *vacrelstats,
- ItemPointer itemptr)
+lazy_record_dead_tuple(LVDeadTuples *dead_tuples, ItemPointer itemptr)
{
/*
* The array shouldn't overflow under normal behavior, but perhaps it
* could if we are given a really small maintenance_work_mem. In that
* case, just forget the last few tuples (we'll get 'em next time).
*/
- if (vacrelstats->num_dead_tuples < vacrelstats->max_dead_tuples)
+ if (dead_tuples->num_tuples < dead_tuples->max_tuples)
{
- vacrelstats->dead_tuples[vacrelstats->num_dead_tuples] = *itemptr;
- vacrelstats->num_dead_tuples++;
+ dead_tuples->itemptrs[dead_tuples->num_tuples] = *itemptr;
+ dead_tuples->num_tuples++;
pgstat_progress_update_param(PROGRESS_VACUUM_NUM_DEAD_TUPLES,
- vacrelstats->num_dead_tuples);
+ dead_tuples->num_tuples);
}
}
@@ -2201,12 +2722,12 @@ lazy_record_dead_tuple(LVRelStats *vacrelstats,
static bool
lazy_tid_reaped(ItemPointer itemptr, void *state)
{
- LVRelStats *vacrelstats = (LVRelStats *) state;
+ LVDeadTuples *dead_tuples = (LVDeadTuples *) state;
ItemPointer res;
res = (ItemPointer) bsearch((void *) itemptr,
- (void *) vacrelstats->dead_tuples,
- vacrelstats->num_dead_tuples,
+ (void *) dead_tuples->itemptrs,
+ dead_tuples->num_tuples,
sizeof(ItemPointerData),
vac_cmp_itemptr);
@@ -2354,3 +2875,330 @@ heap_page_is_all_visible(Relation rel, Buffer buf,
return all_visible;
}
+
+/*
+ * Compute the number of parallel worker processes to request. Both index
+ * vacuuming and index cleanup can be executed together with parallel workers.
+ * The relation sizes of table and indexes don't affect to the parallel
+ * degree for now. nrequested is the number of parallel workers that user
+ * requested. If nrequested is 0 we compute the parallel degree based on
+ * nindexes that is the number of indexes that support parallel index
+ * vacuuming.
+ */
+static int
+compute_parallel_workers(Relation *Irel, int nindexes, int nrequested)
+{
+ bool leaderparticipates = true;
+ int nindexes_to_vacuum = 0;
+ int parallel_workers;
+ int i;
+
+ Assert(nrequested >= 0);
+
+ /* Return immediately when parallelism disabled */
+ if (max_parallel_maintenance_workers == 0)
+ return 0;
+
+ /*
+ * Compute the number of indexes that can participate to parallel index
+ * vacuuming.
+ */
+ for (i = 0; i < nindexes; i++)
+ {
+ IndexAmRoutine *amroutine = GetIndexAmRoutine(Irel[i]->rd_amhandler);
+
+ if (amroutine->amcanparallelvacuum)
+ nindexes_to_vacuum++;
+ }
+
+ /* No index supports parallel index vacuuming */
+ if (nindexes_to_vacuum == 0)
+ return 0;
+
+#ifdef PARALLEL_VACUUM_DISABLE_LEADER_PARTICIPATION
+ leaderparticipates = false;
+#endif
+
+ /* The leader process takes one index */
+ if (leaderparticipates)
+ nindexes_to_vacuum--;
+
+ /* Compute the parallel degree */
+ parallel_workers = (nrequested > 0) ?
+ Min(nrequested, nindexes_to_vacuum) : nindexes_to_vacuum;
+
+ /* cap by max_parallel_maintenace_workers */
+ parallel_workers = Min(parallel_workers, max_parallel_maintenance_workers);
+
+ return parallel_workers;
+}
+
+/*
+ * Enter parallel mode, allocate and initialize the DSM segment.
+ */
+static LVParallelState *
+begin_parallel_vacuum(LVRelStats *vacrelstats, Oid relid, BlockNumber nblocks,
+ Relation *Irel, int nindexes, int nrequested)
+{
+ LVParallelState *lps = (LVParallelState *) palloc(sizeof(LVParallelState));
+ ParallelContext *pcxt;
+ LVShared *shared;
+ LVDeadTuples *dead_tuples;
+ long maxtuples;
+ char *sharedquery;
+ Size est_shared;
+ Size est_deadtuples;
+ int querylen;
+ int i;
+
+ Assert(nrequested > 0);
+ Assert(nindexes > 0);
+
+ lps->leaderparticipates = true;
+
+#ifdef PARALLEL_VACUUM_DISABLE_LEADER_PARTICIPATION
+ lps->leaderparticipates = false;
+#endif
+
+ EnterParallelMode();
+ pcxt = CreateParallelContext("postgres", "heap_parallel_vacuum_main",
+ nrequested);
+ lps->pcxt = pcxt;
+ Assert(pcxt->nworkers > 0);
+
+ /* Estimate size for shared information -- PARALLEL_VACUUM_KEY_SHARED */
+ est_shared = MAXALIGN(add_size(SizeOfLVShared, BITMAPLEN(nindexes)));
+ for (i = 0; i < nindexes; i++)
+ {
+ if (Irel[i]->rd_indam->amcanparallelvacuum)
+ est_shared = add_size(est_shared,
+ add_size(sizeof(LVSharedIndStats),
+ index_parallelvacuum_estimate(Irel[i])));
+ }
+ shm_toc_estimate_chunk(&pcxt->estimator, est_shared);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
+ /* Estimate size for dead tuples -- PARALLEL_VACUUM_KEY_DEAD_TUPLES */
+ maxtuples = compute_max_dead_tuples(nblocks, true);
+ est_deadtuples = MAXALIGN(add_size(SizeOfLVDeadTuples,
+ mul_size(sizeof(ItemPointerData), maxtuples)));
+ shm_toc_estimate_chunk(&pcxt->estimator, est_deadtuples);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
+ /* Finally, estimate PARALLEL_VACUUM_KEY_QUERY_TEXT space */
+ querylen = strlen(debug_query_string);
+ shm_toc_estimate_chunk(&pcxt->estimator, querylen + 1);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
+ InitializeParallelDSM(pcxt);
+
+ /* Prepare shared information */
+ shared = (LVShared *) shm_toc_allocate(pcxt->toc, est_shared);
+ MemSet(shared, 0, est_shared);
+ shared->relid = relid;
+ shared->elevel = elevel;
+ shared->offset = add_size(SizeOfLVShared, BITMAPLEN(nindexes));
+ prepare_index_statistics(shared, Irel, nindexes);
+ pg_atomic_init_u32(&(shared->nprocessed), 0);
+
+ shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_SHARED, shared);
+ lps->lvshared = shared;
+
+ /* Prepare the dead tuple space */
+ dead_tuples = (LVDeadTuples *) shm_toc_allocate(pcxt->toc, est_deadtuples);
+ dead_tuples->max_tuples = maxtuples;
+ dead_tuples->num_tuples = 0;
+ MemSet(dead_tuples->itemptrs, 0, sizeof(ItemPointerData) * maxtuples);
+ shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_DEAD_TUPLES, dead_tuples);
+ vacrelstats->dead_tuples = dead_tuples;
+
+ /* Store query string for workers */
+ sharedquery = (char *) shm_toc_allocate(pcxt->toc, querylen + 1);
+ memcpy(sharedquery, debug_query_string, querylen + 1);
+ sharedquery[querylen] = '\0';
+ shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_QUERY_TEXT, sharedquery);
+
+ return lps;
+}
+
+/*
+ * Initialize variables for shared index statistics, set NULL bitmap and
+ * the struct size of each indexes. Also this function sets the number of
+ * indexes that do not support parallel index vacuuming and that use
+ * maintenance_work_mem. Since currently we don't support parallel vacuum
+ * for autovacuum we don't need to care about autovacuum_work_mem.
+ */
+static void
+prepare_index_statistics(LVShared *lvshared, Relation *Irel, int nindexes)
+{
+ char *p = (char *) GetSharedIndStats(lvshared);
+ int nindexes_mwm = 0;
+ int i;
+
+ Assert(!IsAutoVacuumWorkerProcess());
+
+ for (i = 0; i < nindexes; i++)
+ {
+ LVSharedIndStats *indstats;
+
+ if (!Irel[i]->rd_indam->amcanparallelvacuum)
+ {
+ /* Set NULL as this index does not support parallel vacuum */
+ lvshared->bitmap[i >> 3] |= 0 << (i & 0x07);
+ lvshared->nindexes_nonparallel++;
+ continue;
+ }
+
+ if (Irel[i]->rd_indam->amusemaintenanceworkmem)
+ nindexes_mwm++;
+
+ /* Set the size for index statistics */
+ indstats = (LVSharedIndStats *) p;
+ lvshared->bitmap[i >> 3] |= 1 << (i & 0x07);
+ indstats->size = index_parallelvacuum_estimate(Irel[i]);
+
+ p += SizeOfSharedIndStats(indstats);
+ }
+
+ /* Compute the new maitenance_work_mem value for index vacuuming */
+ lvshared->maintenance_work_mem_worker =
+ (nindexes_mwm > 0) ? maintenance_work_mem / nindexes_mwm : maintenance_work_mem;
+}
+
+/*
+ * Destroy the parallel context, and end parallel mode.
+ *
+ * All writes are not allowed during parallel mode and it might not be
+ * safe to exit from the parallel mode while keeping the parallel context.
+ * So we copy the updated index statistics to a local memory and then later
+ * use that to update the index statistics.
+ */
+static void
+end_parallel_vacuum(LVParallelState *lps, Relation *Irel, int nindexes,
+ IndexBulkDeleteResult **stats)
+{
+ int i;
+
+ Assert(!IsParallelWorker());
+
+ /* copy the updated statistics */
+ for (i = 0; i < nindexes; i++)
+ {
+ LVSharedIndStats *indstats = get_indstats(lps->lvshared, i);
+
+ /*
+ * Skip unused slot. The statistics of this index are already
+ * stored in local memory.
+ */
+ if (indstats == NULL)
+ continue;
+
+ if (indstats->updated)
+ {
+ stats[i] = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
+ memcpy(stats[i],
+ GetIndexBulkDeleteResult(indstats),
+ sizeof(IndexBulkDeleteResult));
+ }
+ else
+ stats[i] = NULL;
+ }
+
+ DestroyParallelContext(lps->pcxt);
+ ExitParallelMode();
+
+ /* Deactivate parallel vacuum */
+ pfree(lps);
+ lps = NULL;
+}
+
+/* Return the Nth index statistics or NULL */
+static LVSharedIndStats *
+get_indstats(LVShared *lvshared, int n)
+{
+ int i;
+ char *p = (char *) GetSharedIndStats(lvshared);;
+
+ if (IndStatsIsNull(lvshared, n))
+ return NULL;
+
+ for (i = 0; i < (n - 1); i++)
+ {
+ if (IndStatsIsNull(lvshared, i))
+ continue;
+
+ p += SizeOfSharedIndStats(p);
+ }
+
+ return (LVSharedIndStats *) p;
+}
+
+/*
+ * Perform work within a launched parallel process.
+ *
+ * Since parallel vacuum workers work only within index vacuuming and index
+ * cleanup, no need to report the progress information.
+ */
+void
+heap_parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
+{
+ Relation onerel;
+ Relation *indrels;
+ LVShared *lvshared;
+ LVDeadTuples *dead_tuples;
+ int nindexes;
+ char *sharedquery;
+ IndexBulkDeleteResult **stats;
+
+ lvshared = (LVShared *) shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_SHARED,
+ false);
+ elevel = lvshared->elevel;
+
+ ereport(DEBUG1,
+ (errmsg("starting parallel lazy vacuum worker for %s",
+ lvshared->for_cleanup ? "cleanup" : "vacuuming")));
+
+ /* Set debug_query_string for individual workers */
+ sharedquery = shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_QUERY_TEXT, false);
+ debug_query_string = sharedquery;
+ pgstat_report_activity(STATE_RUNNING, debug_query_string);
+
+ /*
+ * Open table. The lock mode is the same as the leader process. It's
+ * okay because The lockmode does not conflict among the parallel
+ * workers.
+ */
+ onerel = table_open(lvshared->relid, ShareUpdateExclusiveLock);
+
+ /*
+ * Open all indexes. indrels are sorted in order by OID, which should
+ * be matched to the leader's one.
+ */
+ vac_open_indexes(onerel, RowExclusiveLock, &nindexes, &indrels);
+ Assert(nindexes > 0);
+
+ /* Set dead tuple space */
+ dead_tuples = (LVDeadTuples *) shm_toc_lookup(toc,
+ PARALLEL_VACUUM_KEY_DEAD_TUPLES,
+ false);
+
+ /* Set cost-based vacuum delay */
+ VacuumCostActive = (VacuumCostDelay > 0);
+ VacuumCostBalance = 0;
+ VacuumPageHit = 0;
+ VacuumPageMiss = 0;
+ VacuumPageDirty = 0;
+
+ stats = (IndexBulkDeleteResult **)
+ palloc0(nindexes * sizeof(IndexBulkDeleteResult *));
+
+ if (lvshared->maintenance_work_mem_worker > 0)
+ maintenance_work_mem = lvshared->maintenance_work_mem_worker;
+
+ /* Do either vacuuming indexes or cleaning indexes */
+ vacuum_or_cleanup_indexes_worker(indrels, nindexes, stats, lvshared,
+ dead_tuples);
+
+ vac_close_indexes(nindexes, indrels, RowExclusiveLock);
+ table_close(onerel, ShareUpdateExclusiveLock);
+}
diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 55d129a64f..86511b2703 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -14,6 +14,7 @@
#include "postgres.h"
+#include "access/heapam.h"
#include "access/nbtree.h"
#include "access/parallel.h"
#include "access/session.h"
@@ -140,6 +141,9 @@ static const struct
},
{
"_bt_parallel_build_main", _bt_parallel_build_main
+ },
+ {
+ "heap_parallel_vacuum_main", heap_parallel_vacuum_main
}
};
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 4b67b40b28..9ada501709 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -42,6 +42,7 @@
#include "nodes/makefuncs.h"
#include "pgstat.h"
#include "postmaster/autovacuum.h"
+#include "postmaster/bgworker_internals.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
@@ -99,6 +100,7 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
/* Set default value */
params.index_cleanup = VACOPT_TERNARY_DEFAULT;
params.truncate = VACOPT_TERNARY_DEFAULT;
+ params.nworkers = -1;
/* Parse options list */
foreach(lc, vacstmt->options)
@@ -129,6 +131,28 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
params.index_cleanup = get_vacopt_ternary_value(opt);
else if (strcmp(opt->defname, "truncate") == 0)
params.truncate = get_vacopt_ternary_value(opt);
+ else if (strcmp(opt->defname, "parallel") == 0)
+ {
+ if (opt->arg == NULL)
+ {
+ /*
+ * Parallel lazy vacuum is requested but user didn't specify
+ * the parallel degree. The parallel degree will be determined
+ * at the start of lazy vacuum.
+ */
+ params.nworkers = 0;
+ }
+ else
+ {
+ params.nworkers = defGetInt32(opt);
+ if (params.nworkers < 1 || params.nworkers > MAX_PARALLEL_WORKER_LIMIT)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("parallel vacuum degree must be between 1 and %d",
+ MAX_PARALLEL_WORKER_LIMIT),
+ parser_errposition(pstate, opt->location)));
+ }
+ }
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -170,6 +194,11 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
}
}
+ if ((params.options & VACOPT_FULL) && params.nworkers >= 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot specify FULL option with PARALLEL option")));
+
/*
* All freeze ages are zero if the FREEZE option is given; otherwise pass
* them as -1 which means to use the default values.
@@ -1742,6 +1771,22 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
return false;
}
+ /*
+ * Since parallel workers cannot access data in temporary tables, parallel
+ * vacuum is not allowed for temporary relation.
+ */
+ if (RelationUsesLocalBuffers(onerel) && params->nworkers >= 0)
+ {
+ ereport(WARNING,
+ (errmsg("skipping vacuum on \"%s\" --- cannot vacuum temporary tables in parallel",
+ RelationGetRelationName(onerel))));
+ relation_close(onerel, lmode);
+ PopActiveSnapshot();
+ CommitTransactionCommand();
+ /* It's OK to proceed with ANALYZE on this table */
+ return true;
+ }
+
/*
* Silently ignore partitioned tables as there is no work to be done. The
* useful work is on their child partitions, which have been queued up for
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index c1dd8168ca..c3690f9c41 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2891,6 +2891,8 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map,
(!wraparound ? VACOPT_SKIP_LOCKED : 0);
tab->at_params.index_cleanup = VACOPT_TERNARY_DEFAULT;
tab->at_params.truncate = VACOPT_TERNARY_DEFAULT;
+ /* We don't support parallel vacuum for autovacuum for now */
+ tab->at_params.nworkers = -1;
tab->at_params.freeze_min_age = freeze_min_age;
tab->at_params.freeze_table_age = freeze_table_age;
tab->at_params.multixact_freeze_min_age = multixact_freeze_min_age;
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index e00dbab5aa..321a1511a8 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -3556,7 +3556,7 @@ psql_completion(const char *text, int start, int end)
if (ends_with(prev_wd, '(') || ends_with(prev_wd, ','))
COMPLETE_WITH("FULL", "FREEZE", "ANALYZE", "VERBOSE",
"DISABLE_PAGE_SKIPPING", "SKIP_LOCKED",
- "INDEX_CLEANUP", "TRUNCATE");
+ "INDEX_CLEANUP", "TRUNCATE", "PARALLEL");
else if (TailMatches("FULL|FREEZE|ANALYZE|VERBOSE|DISABLE_PAGE_SKIPPING|SKIP_LOCKED|INDEX_CLEANUP|TRUNCATE"))
COMPLETE_WITH("ON", "OFF");
}
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 858bcb6bc9..12065cc038 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -24,6 +24,8 @@
#include "nodes/primnodes.h"
#include "storage/bufpage.h"
#include "storage/lockdefs.h"
+#include "storage/shm_toc.h"
+#include "storage/dsm.h"
#include "utils/relcache.h"
#include "utils/snapshot.h"
@@ -193,6 +195,7 @@ extern Size SyncScanShmemSize(void);
struct VacuumParams;
extern void heap_vacuum_rel(Relation onerel,
struct VacuumParams *params, BufferAccessStrategy bstrategy);
+extern void heap_parallel_vacuum_main(dsm_segment *seg, shm_toc *toc);
/* in heap/heapam_visibility.c */
extern bool HeapTupleSatisfiesVisibility(HeapTuple stup, Snapshot snapshot,
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index 128f7ae65d..43702f2f86 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -184,6 +184,11 @@ typedef struct VacuumParams
* default value depends on reloptions */
VacOptTernaryValue truncate; /* Truncate empty pages at the end,
* default value depends on reloptions */
+ /*
+ * The number of parallel vacuum workers. -1 by default for no workers
+ * and 0 for choosing based on the number of indexes.
+ */
+ int nworkers;
} VacuumParams;
/* GUC parameters */
diff --git a/src/test/regress/expected/vacuum.out b/src/test/regress/expected/vacuum.out
index aff0b10a93..91db6a10b0 100644
--- a/src/test/regress/expected/vacuum.out
+++ b/src/test/regress/expected/vacuum.out
@@ -92,6 +92,20 @@ CONTEXT: SQL function "do_analyze" statement 1
SQL function "wrap_do_analyze" statement 1
VACUUM FULL vactst;
VACUUM (DISABLE_PAGE_SKIPPING) vaccluster;
+-- PARALLEL option
+VACUUM (PARALLEL) vaccluster;
+VACUUM (PARALLEL 2) vaccluster;
+VACUUM (PARALLEL 0) vaccluster; -- error
+ERROR: parallel vacuum degree must be between 1 and 1024
+LINE 1: VACUUM (PARALLEL 0) vaccluster;
+ ^
+VACUUM (PARALLEL 2, INDEX_CLEANUP FALSE) vaccluster;
+VACUUM (PARALLEL 2, FULL TRUE) vaccluster; -- error, cannot use both PARALLEL and FULL
+ERROR: cannot specify FULL option with PARALLEL option
+CREATE TEMPORARY TABLE tmp (a int PRIMARY KEY);
+CREATE INDEX tmp_idx1 ON tmp (a);
+VACUUM (PARALLEL 1) tmp; -- error, cannot parallel vacuum temporary tables
+WARNING: skipping vacuum on "tmp" --- cannot vacuum temporary tables in parallel
-- INDEX_CLEANUP option
CREATE TABLE no_index_cleanup (i INT PRIMARY KEY, t TEXT);
-- Use uncompressed data stored in toast.
diff --git a/src/test/regress/sql/vacuum.sql b/src/test/regress/sql/vacuum.sql
index f0fee3af2b..66a9b110fe 100644
--- a/src/test/regress/sql/vacuum.sql
+++ b/src/test/regress/sql/vacuum.sql
@@ -75,6 +75,16 @@ VACUUM FULL vactst;
VACUUM (DISABLE_PAGE_SKIPPING) vaccluster;
+-- PARALLEL option
+VACUUM (PARALLEL) vaccluster;
+VACUUM (PARALLEL 2) vaccluster;
+VACUUM (PARALLEL 0) vaccluster; -- error
+VACUUM (PARALLEL 2, INDEX_CLEANUP FALSE) vaccluster;
+VACUUM (PARALLEL 2, FULL TRUE) vaccluster; -- error, cannot use both PARALLEL and FULL
+CREATE TEMPORARY TABLE tmp (a int PRIMARY KEY);
+CREATE INDEX tmp_idx1 ON tmp (a);
+VACUUM (PARALLEL 1) tmp; -- error, cannot parallel vacuum temporary tables
+
-- INDEX_CLEANUP option
CREATE TABLE no_index_cleanup (i INT PRIMARY KEY, t TEXT);
-- Use uncompressed data stored in toast.
--
2.22.0
