On Sat, Sep 21, 2019 at 9:31 PM Amit Kapila <amit.kapil...@gmail.com> wrote:
>
> On Fri, Jun 7, 2019 at 12:03 PM Masahiko Sawada <sawada.m...@gmail.com> wrote:
> >
> > Since the previous version patch conflicts with current HEAD, I've
> > attached the updated version patches.
> >
>
Thank you for reviewing this patch!
> Review comments:
> ------------------------------
> *
> indexes on the relation which further limited by
> + <xref linkend="guc-max-parallel-workers-maintenance"/>.
>
> /which further/which is further
>
Fixed.
> *
> + * index vacuuming or index cleanup, we launch parallel worker processes.
> Once
> + * all indexes are processed the parallel worker processes exit and the
> leader
> + * process re-initializes the DSM segment while keeping recorded dead tuples.
>
> It is not clear for this comment why it re-initializes the DSM segment
> instead of destroying it once the index work is done by workers. Can
> you elaborate a bit more in the comment?
Added more explanation.
>
> *
> + * Note that all parallel workers live during one either index vacuuming or
>
> It seems usage of 'one' is not required in the above sentence.
Removed.
>
> *
> +
> +/*
> + * Compute the number of parallel worker process to request.
>
> /process/processes
Fixed.
>
> *
> +static int
> +compute_parallel_workers(Relation onerel, int nrequested, int nindexes)
> +{
> + int parallel_workers = 0;
> +
> + Assert(nrequested >= 0);
> +
> + if (nindexes <= 1)
> + return 0;
>
> I think here, in the beginning, you can also check if
> max_parallel_maintenance_workers are 0, then return.
>
Agreed, fixed.
> *
> In function compute_parallel_workers, don't we want to cap the number
> of workers based on maintenance_work_mem as we do in
> plan_create_index_workers?
>
> The basic point is how do we want to treat maintenance_work_mem for
> this feature. Do we want all workers to use at max the
> maintenance_work_mem or each worker is allowed to use
> maintenance_work_mem? I would prefer earlier unless we have good
> reason to follow the later strategy.
>
> Accordingly, we might need to update the below paragraph in docs:
> "Note that parallel utility commands should not consume substantially
> more memory than equivalent non-parallel operations. This strategy
> differs from that of parallel query, where resource limits generally
> apply per worker process. Parallel utility commands treat the
> resource limit <varname>maintenance_work_mem</varname> as a limit to
> be applied to the entire utility command, regardless of the number of
> parallel worker processes."
I'd also prefer to use maintenance_work_mem at max during parallel
vacuum regardless of the number of parallel workers. This is current
implementation. In lazy vacuum the maintenance_work_mem is used to
record itempointer of dead tuples. This is done by leader process and
worker processes just refers them for vacuuming dead index tuples.
Even if user sets a small amount of maintenance_work_mem the parallel
vacuum would be helpful as it still would take a time for index
vacuuming. So I thought we should cap the number of parallel workers
by the number of indexes rather than maintenance_work_mem.
>
> *
> +static int
> +compute_parallel_workers(Relation onerel, int nrequested, int nindexes)
> +{
> + int parallel_workers = 0;
> +
> + Assert(nrequested >= 0);
> +
> + if (nindexes <= 1)
> + return 0;
> +
> + if (nrequested > 0)
> + {
> + /* At least one index is taken by the leader process */
> + parallel_workers = Min(nrequested, nindexes - 1);
> + }
>
> I think here we always allow the leader to participate. It seems to
> me we have some way to disable leader participation. During the
> development of previous parallel operations, we find it quite handy to
> catch bugs. We might want to mimic what has been done for index with
> DISABLE_LEADER_PARTICIPATION.
Added the way to disable leader participation.
>
> *
> +/*
> + * 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
>
> I think it would be better if these keys should be assigned numbers in
> a way we do for other similar operation like create index. See below
> defines
> in code:
> /* Magic numbers for parallel state sharing */
> #define PARALLEL_KEY_BTREE_SHARED UINT64CONST(0xA000000000000001)
>
> This will make the code consistent with other parallel operations.
I skipped this comment according to the previous your mail.
>
> *
> +begin_parallel_vacuum(LVRelStats *vacrelstats, Oid relid, BlockNumber
> nblocks,
> + int nindexes, int nrequested)
> {
> ..
> + est_deadtuples = MAXALIGN(add_size(sizeof(LVDeadTuples),
> ..
> }
>
> I think here you should use SizeOfLVDeadTuples as defined by patch.
Fixed.
>
> *
> + keys++;
> +
> + /* Estimate size for dead tuples -- PARALLEL_VACUUM_KEY_DEAD_TUPLES */
> + maxtuples = compute_max_dead_tuples(nblocks, true);
> + est_deadtuples = MAXALIGN(add_size(sizeof(LVDeadTuples),
> + mul_size(sizeof(ItemPointerData), maxtuples)));
> + shm_toc_estimate_chunk(&pcxt->estimator, est_deadtuples);
> + keys++;
> +
> + shm_toc_estimate_keys(&pcxt->estimator, keys);
> +
> + /* Finally, estimate 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);
>
> The code style looks inconsistent here. In some cases, you are
> calling shm_toc_estimate_keys immediately after shm_toc_estimate_chunk
> and in other cases, you are accumulating keys. I think it is better
> to call shm_toc_estimate_keys immediately after shm_toc_estimate_chunk
> in all cases.
Fixed. But there are some code that call shm_toc_estimate_keys for
multiple keys in for example nbtsort.c and parallel.c. What is the
difference?
>
> *
> +void
> +heap_parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
> {
> ..
> + /* Set debug_query_string for individual workers */
> + sharedquery = shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_QUERY_TEXT, true);
> ..
> }
>
> I think the last parameter in shm_toc_lookup should be false. Is
> there a reason for passing it as true?
My bad, fixed.
>
> *
> +void
> +heap_parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
> +{
> ..
> + /* Open table */
> + onerel = heap_open(lvshared->relid, ShareUpdateExclusiveLock);
> ..
> }
>
> I don't think it is a good idea to assume the lock mode as
> ShareUpdateExclusiveLock here. Tomorrow, if due to some reason there
> is a change in lock level for the vacuum process, we might forget to
> update it here. I think it is better if we can get this information
> from the master backend.
So did you mean to declare the lock mode for lazy vacuum somewhere as
a global variable and use it in both try_relation_open in the leader
process and relation_open in the worker process? Otherwise we would
end up with adding something like shared->lmode =
ShareUpdateExclusiveLock during parallel context initialization, which
seems not to resolve your concern.
>
> *
> +end_parallel_vacuum(LVParallelState *lps, Relation *Irel, int nindexes)
> {
> ..
> + /* Shutdown worker processes and destroy the parallel context */
> + WaitForParallelWorkersToFinish(lps->pcxt);
> ..
> }
>
> Do we really need to call WaitForParallelWorkersToFinish here as it
> must have been called in lazy_parallel_vacuum_or_cleanup_indexes
> before this time?
No, removed.
I've attached the updated version patch that incorporated your
comments excluding some comments that needs more discussion. After
discussion I'll update it again.
Regards,
--
Masahiko Sawada
From 80e717cd2a2a49b852f54f1e79cfd1cdd5cfa7d2 Mon Sep 17 00:00:00 2001
From: Masahiko Sawada <sawada.m...@gmail.com>
Date: Wed, 2 Oct 2019 22:46:21 +0900
Subject: [PATCH v26 1/2] 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. Indivisual 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 | 34 +
src/backend/access/heap/vacuumlazy.c | 908 +++++++++++++++++++++++---
src/backend/access/transam/parallel.c | 4 +
src/backend/commands/vacuum.c | 27 +
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 | 10 +
src/test/regress/sql/vacuum.sql | 7 +
11 files changed, 909 insertions(+), 107 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 619ac8c50c..2be71dd128 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2264,13 +2264,13 @@ 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..339ac48033 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 +224,27 @@ 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 on the relation which is further limited by
+ <xref linkend="guc-max-parallel-workers-maintenance"/>. 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 +259,18 @@ 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>
diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index a3c4a1df3b..4ae9736e92 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 is processed by one vacuum
+ * process. At 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
@@ -41,8 +56,10 @@
#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 +72,7 @@
#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 +128,101 @@
*/
#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)
+
+/*
+ * Struct for an index bulk-deletion statistic used for parallel lazy vacuum.
+ * This is allocated in the DSM segment.
+ */
+typedef struct LVSharedIndStats
+{
+ IndexBulkDeleteResult stats;
+ bool updated; /* are the stats updated? */
+} LVSharedIndStats;
+
+/*
+ * 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;
+
+ /*
+ * Variables to control parallel index vacuuming. An variable-sized field
+ * 'indstats' must come last.
+ */
+ pg_atomic_uint32 nprocessed;
+ LVSharedIndStats indstats[FLEXIBLE_ARRAY_MEMBER];
+} LVShared;
+#define SizeOfLVShared offsetof(LVShared, indstats) + sizeof(LVSharedIndStats)
+
+/* Struct for parallel lazy vacuum */
+typedef struct LVParallelState
+{
+ ParallelContext *pcxt;
+ LVShared *lvshared;
+ int nworkers_requested; /* user-requested parallel degree */
+} LVParallelState;
+
typedef struct LVRelStats
{
/* useindex = true means two-pass strategy; false means one-pass */
@@ -128,17 +241,12 @@ 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;
} LVRelStats;
-
/* A few variables that don't seem worth passing around as parameters */
static int elevel = -1;
@@ -155,12 +263,11 @@ 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 +276,33 @@ 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 void lazy_update_index_statistics(Relation indrel, IndexBulkDeleteResult *stats);
+static LVParallelState *begin_parallel_vacuum(LVRelStats *vacrelstats, Oid relid,
+ BlockNumber nblocks, int nindexes,
+ int nrequested);
+static void end_parallel_vacuum(LVParallelState *lps, Relation *Irel, int nindexes);
+static void lazy_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes,
+ IndexBulkDeleteResult **stats,
+ LVParallelState *lps, bool for_cleanup);
+static void lazy_parallel_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats,
+ Relation *Irel,
+ int nindexes,
+ IndexBulkDeleteResult **stats,
+ LVParallelState *lps,
+ bool for_cleanup);
+static void do_parallel_vacuum_or_cleanup_indexes(Relation *Irel, int nindexes,
+ IndexBulkDeleteResult **stats,
+ LVShared *lvshared,
+ LVDeadTuples *dead_tuples);
+static int compute_parallel_workers(Relation onerel, int nrequested, int nindexes);
+static long compute_max_dead_tuples(BlockNumber relblocks, bool hasindex);
/*
@@ -488,6 +616,17 @@ 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
+ * create the parallel context and the DSM segment before starting heap
+ * scan. All parallel workers are launched at beginning of index vacuuming
+ * and index cleanup and they exit once done with all indexes. At 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 +635,8 @@ 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 +659,7 @@ 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 +695,45 @@ 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(onerel,
+ params->nworkers,
+ nindexes);
+
+ if (parallel_workers > 0)
+ {
+ /*
+ * Enter parallel mode, create the parallel context and allocate the
+ * DSM segment.
+ */
+ lps = begin_parallel_vacuum(vacrelstats,
+ RelationGetRelid(onerel),
+ nblocks, nindexes,
+ parallel_workers);
+
+ /* Remember the user-requested parallel degree for reporting */
+ lps->nworkers_requested = params->nworkers;
+ }
+ 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 +911,8 @@ 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 +940,8 @@ 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_or_cleanup_indexes(vacrelstats, Irel, nindexes,
+ indstats, lps, false);
/*
* Report that we are now vacuuming the heap. We also increase
@@ -789,7 +961,7 @@ 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 +1157,7 @@ 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 +1196,7 @@ 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 +1342,7 @@ 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 +1412,7 @@ 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 +1441,7 @@ 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 +1556,7 @@ 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 +1590,7 @@ 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 +1606,8 @@ 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_or_cleanup_indexes(vacrelstats, Irel, nindexes,
+ indstats, lps, false);
/* Report that we are now vacuuming the heap */
hvp_val[0] = PROGRESS_VACUUM_PHASE_VACUUM_HEAP;
@@ -1463,11 +1633,20 @@ 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 and statistics update for each index if
+ * we're not in parallel lazy vacuum. If in parallel lazy vacuum, do
+ * only post-vacuum cleanup and will update statistics at the end of
+ * the parallel lazy vacuum.
+ */
if (vacrelstats->useindex)
+ lazy_vacuum_or_cleanup_indexes(vacrelstats, Irel, nindexes,
+ indstats, lps, true);
+
+ if (ParallelVacuumIsActive(lps))
{
- for (i = 0; i < nindexes; i++)
- lazy_cleanup_index(Irel[i], indstats[i], vacrelstats);
+ /* End parallel mode and update index statistics */
+ end_parallel_vacuum(lps, Irel, nindexes);
}
/* If no indexes, make log report that lazy_vacuum_heap would've made */
@@ -1534,7 +1713,7 @@ 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 +1722,7 @@ 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 +1770,7 @@ 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 +1781,16 @@ 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 +1911,289 @@ lazy_check_needs_freeze(Buffer buf, bool *hastup)
return false;
}
+/*
+ * Vacuum or cleanup indexes with parallel workers. This function must be used
+ * by the parallel vacuum leader process.
+ */
+static void
+lazy_parallel_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps, bool for_cleanup)
+{
+ StringInfoData buf;
+ bool leaderparticipates = true;
+
+#ifdef PARALLEL_VACUUM_DISABLE_LEADER_PARTICIPATION
+ leaderparticipates = false;
+#endif
+
+ Assert(!IsParallelWorker());
+ Assert(ParallelVacuumIsActive(lps));
+ Assert(nindexes > 0);
+
+ /* Set shared information to tell parallel workers */
+ lps->lvshared->for_cleanup = for_cleanup;
+ if (!for_cleanup)
+ {
+ /*
+ * 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;
+ }
+ else
+ {
+ /*
+ * 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);
+
+ }
+
+ LaunchParallelWorkers(lps->pcxt);
+
+ /* Create the log message to report */
+ initStringInfo(&buf);
+ if (lps->pcxt->nworkers_launched == 0)
+ {
+ /*
+ * If no workers launched, the leader process vacuums all indexes alone.
+ * Since there is hope that we can launch parallel workers in the next
+ * index vacuuming time we don't end parallel mode yet.
+ */
+ if (for_cleanup)
+ {
+ if (lps->nworkers_requested > 0)
+ appendStringInfo(&buf,
+ gettext_noop("could not launch parallel vacuum worker for index cleanup (planned: %d, requested: %d)"),
+ lps->pcxt->nworkers, lps->nworkers_requested);
+ else
+ appendStringInfo(&buf,
+ gettext_noop("could not launch parallel vacuum worker for index cleanup (planned: %d)"),
+ lps->pcxt->nworkers);
+ }
+ else
+ {
+ if (lps->nworkers_requested > 0)
+ appendStringInfo(&buf,
+ gettext_noop("could not launch parallel vacuum worker for index vacuuming (planned: %d, requested: %d)"),
+ lps->pcxt->nworkers, lps->nworkers_requested);
+ else
+ appendStringInfo(&buf,
+ gettext_noop("could not launch parallel vacuum worker for index vacuuming (planned: %d)"),
+ lps->pcxt->nworkers);
+ }
+ }
+ else
+ {
+ if (for_cleanup)
+ {
+ if (lps->nworkers_requested > 0)
+ appendStringInfo(&buf,
+ ngettext("launched %d parallel vacuum worker for index cleanup (planned: %d, requested %d)",
+ "launched %d parallel vacuum workers for index cleanup (planned: %d, requsted %d)",
+ lps->pcxt->nworkers_launched),
+ lps->pcxt->nworkers_launched,
+ lps->pcxt->nworkers,
+ lps->nworkers_requested);
+ else
+ appendStringInfo(&buf,
+ 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);
+ }
+ else
+ {
+ if (lps->nworkers_requested > 0)
+ appendStringInfo(&buf,
+ ngettext("launched %d parallel vacuum worker for index vacuuming (planned: %d, requested %d)",
+ "launched %d parallel vacuum workers for index vacuuming (planned: %d, requested %d)",
+ lps->pcxt->nworkers_launched),
+ lps->pcxt->nworkers_launched,
+ lps->pcxt->nworkers,
+ lps->nworkers_requested);
+ else
+ appendStringInfo(&buf,
+ 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);
+ }
+ }
+
+ ereport(elevel, (errmsg("%s", buf.data)));
+
+ /*
+ * Join index vacuuming or index cleanup with parallel workers. The
+ * leader process alone does that in case where no workers launched.
+ */
+ if (leaderparticipates || lps->pcxt->nworkers_launched == 0)
+ do_parallel_vacuum_or_cleanup_indexes(Irel, nindexes, stats,
+ lps->lvshared,
+ vacrelstats->dead_tuples);
+
+ /* Wait for all vacuum workers to finish */
+ WaitForParallelWorkersToFinish(lps->pcxt);
+
+ /*
+ * If we are doing index cleanup, we don't need to reinitialize the
+ * parallel context as no more index vacuuming and index cleanup will
+ * be performed after that.
+ */
+ if (!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);
+ }
+}
+
+/*
+ * Parallel Index vacuuming and index cleanup routine used by both the leader
+ * process and worker processes. Unlike single process vacuum, we don't update
+ * index statistics after cleanup index since it is not allowed during
+ * parallel mode, instead copy index bulk-deletion results from the local
+ * memory to the DSM segment and update them at the end of parallel lazy
+ * vacuum.
+ */
+static void
+do_parallel_vacuum_or_cleanup_indexes(Relation *Irel, int nindexes,
+ IndexBulkDeleteResult **stats,
+ LVShared *lvshared,
+ LVDeadTuples *dead_tuples)
+{
+ /* Loop until all indexes are vacuumed */
+ for (;;)
+ {
+ int idx;
+
+ /* Get an index number to process */
+ idx = pg_atomic_fetch_add_u32(&(lvshared->nprocessed), 1);
+
+ /* Done for all indexes? */
+ if (idx >= nindexes)
+ break;
+
+ /*
+ * Update the pointer to the corresponding bulk-deletion result
+ * if someone has already updated it.
+ */
+ if (lvshared->indstats[idx].updated &&
+ stats[idx] == NULL)
+ stats[idx] = &(lvshared->indstats[idx].stats);
+
+ /* Do vacuum or cleanup one index */
+ if (!lvshared->for_cleanup)
+ lazy_vacuum_index(Irel[idx], &stats[idx], dead_tuples,
+ lvshared->reltuples);
+ else
+ lazy_cleanup_index(Irel[idx], &stats[idx], lvshared->reltuples,
+ lvshared->estimated_count);
+
+ /*
+ * 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 (!lvshared->indstats[idx].updated && stats[idx] != NULL)
+ {
+ memcpy(&(lvshared->indstats[idx].stats),
+ stats[idx], sizeof(IndexBulkDeleteResult));
+ lvshared->indstats[idx].updated = true;
+
+ /*
+ * no longer need the locally allocated result and now stats[idx]
+ * points to the DSM segment.
+ */
+ pfree(stats[idx]);
+ stats[idx] = &(lvshared->indstats[idx].stats);
+ }
+ }
+}
+
+/*
+ * Vacuum or cleanup indexes. If we're ready for parallel lazy vacuum it's
+ * performed with parallel workers, otherwise do vacuum or cleanup indexes
+ * by itself. In parallel vacuum case, this function must be used by the
+ * parallel vacuum leader process. for_cleanup is true if the caller requests
+ * index cleanup, otherwise index vacuuming.
+ */
+static void
+lazy_vacuum_or_cleanup_indexes(LVRelStats *vacrelstats, Relation *Irel,
+ int nindexes, IndexBulkDeleteResult **stats,
+ LVParallelState *lps, bool for_cleanup)
+{
+ int idx;
+
+ Assert(!IsParallelWorker());
+
+ /* no job if the table has no index */
+ if (nindexes <= 0)
+ return;
+
+ if (ParallelVacuumIsActive(lps))
+ {
+ /* Do parallel index vacuuming or index cleanup */
+ lazy_parallel_vacuum_or_cleanup_indexes(vacrelstats, Irel,
+ nindexes, stats,
+ lps, for_cleanup);
+ return;
+ }
+
+ /* We are in single process vacuum, do index vacuuming or index cleanup */
+ for (idx = 0; idx < nindexes; idx++)
+ {
+ if (!for_cleanup)
+ lazy_vacuum_index(Irel[idx], &stats[idx], vacrelstats->dead_tuples,
+ vacrelstats->old_live_tuples);
+ else
+ {
+ /* Cleanup one index and update index statistics */
+ lazy_cleanup_index(Irel[idx], &stats[idx], vacrelstats->new_rel_tuples,
+ vacrelstats->tupcount_pages < vacrelstats->rel_pages);
+
+ lazy_update_index_statistics(Irel[idx], stats[idx]);
+
+ if (stats[idx])
+ pfree(stats[idx]);
+ }
+ }
+}
/*
* 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 +2203,38 @@ 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 +2242,55 @@ 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
+lazy_update_index_statistics(Relation indrel, IndexBulkDeleteResult *stats)
+{
+ Assert(!IsInParallelMode());
+
+ if (!stats || stats->estimated_count)
+ return;
- pfree(stats);
+ /* Update index statistics */
+ vac_update_relstats(indrel,
+ stats->num_pages,
+ stats->num_index_tuples,
+ 0,
+ false,
+ InvalidTransactionId,
+ InvalidMultiXactId,
+ false);
}
/*
@@ -2134,19 +2598,17 @@ 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 +2622,49 @@ 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 +2678,12 @@ 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 +2831,236 @@ 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 the table has.
+ */
+static int
+compute_parallel_workers(Relation onerel, int nrequested, int nindexes)
+{
+ int parallel_workers;
+ bool leaderparticipates = true;
+ int nindexes_to_vacuum = nindexes;
+
+#ifdef PARALLEL_VACUUM_DISABLE_LEADER_PARTICIPATION
+ leaderparticipates = false;
+#endif
+
+ Assert(nrequested >= 0);
+
+ /* Return immediately when parallelism disabled */
+ if (max_parallel_maintenance_workers == 0)
+ return 0;
+
+ /* The leader process takes one index */
+ if (leaderparticipates)
+ nindexes_to_vacuum--;
+
+ if (nrequested > 0)
+ {
+ /* The parallel degree is requested */
+ parallel_workers = Min(nrequested, nindexes_to_vacuum);
+ }
+ else
+ {
+ /*
+ * The parallel degree is not requested. Compute it based on the
+ * number of indexes.
+ */
+ parallel_workers = 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,
+ int nindexes, int nrequested)
+{
+ LVParallelState *lps = (LVParallelState *) palloc(sizeof(LVParallelState));
+ LVShared *shared;
+ ParallelContext *pcxt;
+ LVDeadTuples *tidmap;
+ long maxtuples;
+ char *sharedquery;
+ Size est_shared;
+ Size est_deadtuples;
+ int querylen;
+
+ Assert(nrequested > 0);
+ Assert(nindexes > 0);
+
+ 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,
+ mul_size(sizeof(LVSharedIndStats), nindexes)));
+ 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 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);
+ shared->relid = relid;
+ shared->elevel = elevel;
+ pg_atomic_init_u32(&(shared->nprocessed), 0);
+ MemSet(shared->indstats, 0, sizeof(LVSharedIndStats) * nindexes);
+ shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_SHARED, shared);
+ lps->lvshared = shared;
+
+ /* prepare the dead tuple space */
+ tidmap = (LVDeadTuples *) shm_toc_allocate(pcxt->toc, est_deadtuples);
+ tidmap->max_tuples = maxtuples;
+ tidmap->num_tuples = 0;
+ MemSet(tidmap->itemptrs, 0, sizeof(ItemPointerData) * maxtuples);
+ shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_DEAD_TUPLES, tidmap);
+ vacrelstats->dead_tuples = tidmap;
+
+ /* 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);
+
+ lps->nworkers_requested = 0;
+
+ return lps;
+}
+
+/*
+ * Shutdown workers, destroy the parallel context, and end parallel mode.
+ * Update index statistics after exited from parallel mode.
+ */
+static void
+end_parallel_vacuum(LVParallelState *lps, Relation *Irel, int nindexes)
+{
+ IndexBulkDeleteResult *copied_stats = NULL;
+ int *updated_idx = palloc(sizeof(int) * nindexes);
+ int nupdated = 0;
+ int i;
+
+ Assert(!IsParallelWorker());
+ Assert(Irel != NULL && nindexes > 0);
+
+ /*
+ * All writes are not allowed during parallel mode and it might not be
+ * safe to exit from parallel mode while keeping the parallel context.
+ * So we copy the updated index statistics to a temporary space and
+ * update them after exited from parallel mode.
+ */
+ for (i = 0; i < nindexes; i++)
+ {
+ if (lps->lvshared->indstats[i].updated)
+ updated_idx[nupdated++] = i;
+ }
+
+ copied_stats = palloc(sizeof(IndexBulkDeleteResult) * nupdated);
+
+ for (i = 0; i < nupdated; i++)
+ memcpy(&(copied_stats[i]),
+ &(lps->lvshared->indstats[updated_idx[i]].stats),
+ sizeof(IndexBulkDeleteResult));
+
+ /* Shutdown worker processes and destroy the parallel context */
+ DestroyParallelContext(lps->pcxt);
+ ExitParallelMode();
+
+ /* Update index statistics */
+ for (i = 0; i < nupdated; i++)
+ lazy_update_index_statistics(Irel[updated_idx[i]],
+ &(copied_stats[i]));
+
+ pfree(copied_stats);
+ pfree(updated_idx);
+}
+
+/*
+ * 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 */
+ onerel = heap_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 *));
+
+ /* Do either vacuuming indexes or cleaning indexes */
+ do_parallel_vacuum_or_cleanup_indexes(indrels, nindexes, stats,
+ lvshared, dead_tuples);
+
+ vac_close_indexes(nindexes, indrels, RowExclusiveLock);
+ heap_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 e154507ecd..78e2fe6c3f 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -99,6 +99,7 @@ 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 +130,27 @@ 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)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("parallel vacuum degree must be at least 1"),
+ parser_errposition(pstate, opt->location)));
+ }
+ }
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
@@ -170,6 +192,11 @@ 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.
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 073f313337..da21d62635 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2888,6 +2888,8 @@ 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;
+ /* parallel lazy vacuum is not supported for autovacuum */
+ 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..7fa981c649 100644
--- a/src/test/regress/expected/vacuum.out
+++ b/src/test/regress/expected/vacuum.out
@@ -92,6 +92,16 @@ 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 at least 1
+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
-- 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..30f4c38ac8 100644
--- a/src/test/regress/sql/vacuum.sql
+++ b/src/test/regress/sql/vacuum.sql
@@ -75,6 +75,13 @@ 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
+
-- INDEX_CLEANUP option
CREATE TABLE no_index_cleanup (i INT PRIMARY KEY, t TEXT);
-- Use uncompressed data stored in toast.
--
2.22.0
From 7085bef4caf59066ac9e09da240b03173b549d1c 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 v26 2/2] 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
