Jim Nasby <jim.na...@bluetreble.com> writes:
> https://commitfest.postgresql.org/action/patch_view?id=1661 (apologies for
> not replying to the thread; I can't find it in my inbox)
>
> Patch applies and passes make check. Code formatting looks good.
Jim,
> The regression test partially tests this. It does not cover 2PC, nor
> does it test rolling back a subtransaction that contains a
> truncate. The latter actually doesn't work correctly.
Thanks for pointing out the missing 2PC test, I've added one.
The test you've added for rolling back a subxact actually works
correctly, if you consider the fact that aborted (sub)xacts still
account for insert/update/delete in pgstat. I've added this test with
the corrected expected results.
> The test also adds 2.5 seconds of forced pg_sleep. I think that's both
> bad and unnecessary. When I removed the sleeps I still saw times of
> less than 0.1 seconds.
Well, I never liked that part, but the stats don't get updated if we
don't put the session to sleep for at least PGSTAT_STAT_INTERVAL (which
is 500ms).
Removing these extra sleep calls would theoretically not make a
difference as wait_for_trunc_test_stats() seems to have enough sleep
calls itself, but due to the pgstat_report_stat() being called from the
main loop only, there's no way short of placing the explicit pg_sleep at
top level, if we want to be able to check the effects reproducibly.
Another idea would be exposing pgstat_report_stat(true) at SQL level.
That would eleminate the need for explicit pg_sleep(>=0.5), but we'll
still need the wait_for_... call to make sure the collector has picked
it up.
> Also, wait_for_trunc_test_stats() should display something if it times
> out; otherwise you'll have a test failure and won't have any
> indication why.
Oh, good catch. Since I've copied this function from stats.sql, we
might want to update that one too in a separate commit.
> I've attached a patch that adds logging on timeout and contains a test
> case that demonstrates the rollback to savepoint bug.
I'm attaching the updated patch version.
Thank you for the review!
--
Alex
PS: re: your CF comment: I'm producing the patches using
git format-patch --ext-diff
where diff.external is set to '/bin/bash src/tools/git-external-diff'.
Now that I try to apply it using git, looks like git doesn't like the
copied context diff very much...
>From cc51823a01a194ef6fcd90bc763fa26498837322 Mon Sep 17 00:00:00 2001
From: Alex Shulgin <a...@commandprompt.com>
Date: Tue, 9 Dec 2014 16:35:14 +0300
Subject: [PATCH] WIP: track TRUNCATEs in pgstat transaction stats.
The n_live_tup and n_dead_tup counters need to be set to 0 after a
TRUNCATE on the relation. We can't issue a special message to the stats
collector because the xact might be later aborted, so we track the fact
that the relation was truncated during the xact (and reset this xact's
insert/update/delete counters). When xact is committed, we use the
`truncated' flag to reset the n_live_tup and n_dead_tup counters.
---
src/backend/commands/tablecmds.c | 3 +
src/backend/postmaster/pgstat.c | 52 ++++++++-
src/include/pgstat.h | 3 +
src/test/regress/expected/prepared_xacts.out | 50 ++++++++
src/test/regress/expected/truncate.out | 164 +++++++++++++++++++++++++++
src/test/regress/sql/prepared_xacts.sql | 27 +++++
src/test/regress/sql/truncate.sql | 118 +++++++++++++++++++
7 files changed, 414 insertions(+), 3 deletions(-)
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
new file mode 100644
index 1e737a0..4f0e3d8
*** a/src/backend/commands/tablecmds.c
--- b/src/backend/commands/tablecmds.c
***************
*** 71,76 ****
--- 71,77 ----
#include "parser/parse_type.h"
#include "parser/parse_utilcmd.h"
#include "parser/parser.h"
+ #include "pgstat.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteHandler.h"
#include "rewrite/rewriteManip.h"
*************** ExecuteTruncate(TruncateStmt *stmt)
*** 1224,1229 ****
--- 1225,1232 ----
*/
reindex_relation(heap_relid, REINDEX_REL_PROCESS_TOAST);
}
+
+ pgstat_count_heap_truncate(rel);
}
/*
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
new file mode 100644
index f71fdeb..b02e4a1
*** a/src/backend/postmaster/pgstat.c
--- b/src/backend/postmaster/pgstat.c
*************** typedef struct TwoPhasePgStatRecord
*** 201,206 ****
--- 201,207 ----
PgStat_Counter tuples_deleted; /* tuples deleted in xact */
Oid t_id; /* table's OID */
bool t_shared; /* is it a shared catalog? */
+ bool t_truncated; /* was the relation truncated? */
} TwoPhasePgStatRecord;
/*
*************** pgstat_count_heap_delete(Relation rel)
*** 1864,1869 ****
--- 1865,1894 ----
}
/*
+ * pgstat_count_heap_truncate - update tuple counters due to truncate
+ */
+ void
+ pgstat_count_heap_truncate(Relation rel)
+ {
+ PgStat_TableStatus *pgstat_info = rel->pgstat_info;
+
+ if (pgstat_info != NULL)
+ {
+ /* We have to log the effect at the proper transactional level */
+ int nest_level = GetCurrentTransactionNestLevel();
+
+ if (pgstat_info->trans == NULL ||
+ pgstat_info->trans->nest_level != nest_level)
+ add_tabstat_xact_level(pgstat_info, nest_level);
+
+ pgstat_info->trans->tuples_inserted = 0;
+ pgstat_info->trans->tuples_updated = 0;
+ pgstat_info->trans->tuples_deleted = 0;
+ pgstat_info->trans->truncated = true;
+ }
+ }
+
+ /*
* pgstat_update_heap_dead_tuples - update dead-tuples count
*
* The semantics of this are that we are reporting the nontransactional
*************** AtEOXact_PgStat(bool isCommit)
*** 1927,1932 ****
--- 1952,1959 ----
tabstat->t_counts.t_tuples_deleted += trans->tuples_deleted;
if (isCommit)
{
+ tabstat->t_counts.t_truncated = trans->truncated;
+
/* insert adds a live tuple, delete removes one */
tabstat->t_counts.t_delta_live_tuples +=
trans->tuples_inserted - trans->tuples_deleted;
*************** AtEOSubXact_PgStat(bool isCommit, int ne
*** 1991,1999 ****
{
if (trans->upper && trans->upper->nest_level == nestDepth - 1)
{
! trans->upper->tuples_inserted += trans->tuples_inserted;
! trans->upper->tuples_updated += trans->tuples_updated;
! trans->upper->tuples_deleted += trans->tuples_deleted;
tabstat->trans = trans->upper;
pfree(trans);
}
--- 2018,2037 ----
{
if (trans->upper && trans->upper->nest_level == nestDepth - 1)
{
! if (trans->truncated)
! {
! trans->upper->truncated = true;
! /* replace upper xact stats with ours */
! trans->upper->tuples_inserted = trans->tuples_inserted;
! trans->upper->tuples_updated = trans->tuples_updated;
! trans->upper->tuples_deleted = trans->tuples_deleted;
! }
! else
! {
! trans->upper->tuples_inserted += trans->tuples_inserted;
! trans->upper->tuples_updated += trans->tuples_updated;
! trans->upper->tuples_deleted += trans->tuples_deleted;
! }
tabstat->trans = trans->upper;
pfree(trans);
}
*************** AtPrepare_PgStat(void)
*** 2072,2077 ****
--- 2110,2116 ----
record.tuples_deleted = trans->tuples_deleted;
record.t_id = tabstat->t_id;
record.t_shared = tabstat->t_shared;
+ record.t_truncated = trans->truncated;
RegisterTwoPhaseRecord(TWOPHASE_RM_PGSTAT_ID, 0,
&record, sizeof(TwoPhasePgStatRecord));
*************** pgstat_twophase_postcommit(TransactionId
*** 2137,2142 ****
--- 2176,2183 ----
pgstat_info->t_counts.t_tuples_inserted += rec->tuples_inserted;
pgstat_info->t_counts.t_tuples_updated += rec->tuples_updated;
pgstat_info->t_counts.t_tuples_deleted += rec->tuples_deleted;
+ pgstat_info->t_counts.t_truncated = rec->t_truncated;
+
pgstat_info->t_counts.t_delta_live_tuples +=
rec->tuples_inserted - rec->tuples_deleted;
pgstat_info->t_counts.t_delta_dead_tuples +=
*************** pgstat_recv_tabstat(PgStat_MsgTabstat *m
*** 4685,4690 ****
--- 4726,4736 ----
tabentry->tuples_updated += tabmsg->t_counts.t_tuples_updated;
tabentry->tuples_deleted += tabmsg->t_counts.t_tuples_deleted;
tabentry->tuples_hot_updated += tabmsg->t_counts.t_tuples_hot_updated;
+ if (tabmsg->t_counts.t_truncated)
+ {
+ tabentry->n_live_tuples = 0;
+ tabentry->n_dead_tuples = 0;
+ }
tabentry->n_live_tuples += tabmsg->t_counts.t_delta_live_tuples;
tabentry->n_dead_tuples += tabmsg->t_counts.t_delta_dead_tuples;
tabentry->changes_since_analyze += tabmsg->t_counts.t_changed_tuples;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
new file mode 100644
index 0892533..5107f48
*** a/src/include/pgstat.h
--- b/src/include/pgstat.h
*************** typedef struct PgStat_TableCounts
*** 103,108 ****
--- 103,109 ----
PgStat_Counter t_tuples_updated;
PgStat_Counter t_tuples_deleted;
PgStat_Counter t_tuples_hot_updated;
+ bool t_truncated;
PgStat_Counter t_delta_live_tuples;
PgStat_Counter t_delta_dead_tuples;
*************** typedef struct PgStat_TableXactStatus
*** 164,169 ****
--- 165,171 ----
PgStat_Counter tuples_inserted; /* tuples inserted in (sub)xact */
PgStat_Counter tuples_updated; /* tuples updated in (sub)xact */
PgStat_Counter tuples_deleted; /* tuples deleted in (sub)xact */
+ bool truncated; /* relation got truncated in this (sub)xact */
int nest_level; /* subtransaction nest level */
/* links to other structs for same relation: */
struct PgStat_TableXactStatus *upper; /* next higher subxact if any */
*************** extern void pgstat_initstats(Relation re
*** 916,921 ****
--- 918,924 ----
extern void pgstat_count_heap_insert(Relation rel, int n);
extern void pgstat_count_heap_update(Relation rel, bool hot);
extern void pgstat_count_heap_delete(Relation rel);
+ extern void pgstat_count_heap_truncate(Relation rel);
extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
extern void pgstat_init_function_usage(FunctionCallInfoData *fcinfo,
diff --git a/src/test/regress/expected/prepared_xacts.out b/src/test/regress/expected/prepared_xacts.out
new file mode 100644
index c0b0864..9dbf874
*** a/src/test/regress/expected/prepared_xacts.out
--- b/src/test/regress/expected/prepared_xacts.out
*************** SELECT gid FROM pg_prepared_xacts;
*** 247,254 ****
--- 247,304 ----
-----
(0 rows)
+ CREATE TABLE pxtest5 (a SERIAL);
+ INSERT INTO pxtest5 DEFAULT VALUES;
+ SELECT * FROM pxtest5;
+ a
+ ---
+ 1
+ (1 row)
+
+ BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+ INSERT INTO pxtest5 DEFAULT VALUES;
+ INSERT INTO pxtest5 DEFAULT VALUES;
+ TRUNCATE pxtest5;
+ INSERT INTO pxtest5 DEFAULT VALUES;
+ PREPARE TRANSACTION 'trunc-and-pgstat';
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='pxtest5';
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 1 | 0 | 0 | 1 | 0
+ (1 row)
+
+ COMMIT PREPARED 'trunc-and-pgstat';
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='pxtest5';
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 2 | 0 | 0 | 1 | 0
+ (1 row)
+
+ SELECT * FROM pxtest5;
+ a
+ ---
+ 4
+ (1 row)
+
-- Clean up
DROP TABLE pxtest2;
DROP TABLE pxtest3; -- will still be there if prepared xacts are disabled
ERROR: table "pxtest3" does not exist
DROP TABLE pxtest4;
+ DROP TABLE pxtest5;
diff --git a/src/test/regress/expected/truncate.out b/src/test/regress/expected/truncate.out
new file mode 100644
index 5c5277e..f062e87
*** a/src/test/regress/expected/truncate.out
--- b/src/test/regress/expected/truncate.out
*************** SELECT nextval('truncate_a_id1'); -- fai
*** 420,422 ****
--- 420,586 ----
ERROR: relation "truncate_a_id1" does not exist
LINE 1: SELECT nextval('truncate_a_id1');
^
+ -- test effects of TRUNCATE on pgstat n_live_tup/n_dead_tup counters
+ CREATE TABLE trunc_stats_test(id serial);
+ CREATE TEMP TABLE prevstats AS
+ SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='trunc_stats_test';
+ create function wait_for_trunc_test_stats() returns prevstats as $$
+ declare
+ start_time timestamptz := clock_timestamp();
+ newstats prevstats;
+ updated bool;
+ begin
+ -- we don't want to wait forever; loop will exit after 30 seconds
+ for i in 1 .. 300 loop
+
+ SELECT INTO newstats
+ n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='trunc_stats_test';
+
+ SELECT INTO updated
+ row(p.*) <> newstats
+ FROM prevstats p;
+
+ exit when updated;
+
+ -- wait a little
+ perform pg_sleep(0.1);
+
+ -- reset stats snapshot so we can test again
+ perform pg_stat_clear_snapshot();
+
+ end loop;
+
+ IF NOT updated THEN
+ RAISE WARNING 'stats update never happened';
+ END IF;
+
+ TRUNCATE prevstats; -- what a pun
+ INSERT INTO prevstats SELECT newstats.*;
+
+ -- report time waited in postmaster log (where it won't change test output)
+ raise log 'wait_for_stats delayed % seconds',
+ extract(epoch from clock_timestamp() - start_time);
+
+ RETURN newstats;
+ end
+ $$ language plpgsql;
+ -- populate the table so we can check that n_live_tup is reset to 0
+ -- after truncate
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ -- wait for stats collector to update
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT * FROM wait_for_trunc_test_stats();
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 3 | 0 | 0 | 3 | 0
+ (1 row)
+
+ TRUNCATE trunc_stats_test;
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT * FROM wait_for_trunc_test_stats();
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 3 | 0 | 0 | 0 | 0
+ (1 row)
+
+ -- repopulate the table
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ UPDATE trunc_stats_test SET id = id + 10 WHERE id < 6; -- UPDATE 2
+ DELETE FROM trunc_stats_test WHERE id = 6; -- DELETE 1
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT * FROM wait_for_trunc_test_stats();
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 6 | 2 | 1 | 2 | 3
+ (1 row)
+
+ BEGIN;
+ UPDATE trunc_stats_test SET id = id + 100; -- UPDATE 2
+ TRUNCATE trunc_stats_test;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ COMMIT;
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT * FROM wait_for_trunc_test_stats();
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 7 | 2 | 1 | 1 | 0
+ (1 row)
+
+ -- now to use a savepoint: this should only count 1 insert and have 1
+ -- live tuple after commit
+ BEGIN;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ SAVEPOINT p1;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ TRUNCATE trunc_stats_test;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ RELEASE SAVEPOINT p1;
+ COMMIT;
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT * FROM wait_for_trunc_test_stats();
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 8 | 2 | 1 | 1 | 0
+ (1 row)
+
+ -- rollback a savepoint: this should only count 3 inserts and have 3
+ -- live tuples after commit (and 1 dead one due to aborted subxact)
+ BEGIN;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ SAVEPOINT p1;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ TRUNCATE trunc_stats_test;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ ROLLBACK TO SAVEPOINT p1;
+ COMMIT;
+ SELECT pg_sleep(0.5);
+ pg_sleep
+ ----------
+
+ (1 row)
+
+ SELECT * FROM wait_for_trunc_test_stats();
+ n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup
+ -----------+-----------+-----------+------------+------------
+ 11 | 2 | 1 | 3 | 1
+ (1 row)
+
+ DROP TABLE prevstats CASCADE;
+ NOTICE: drop cascades to function wait_for_trunc_test_stats()
+ DROP TABLE trunc_stats_test;
diff --git a/src/test/regress/sql/prepared_xacts.sql b/src/test/regress/sql/prepared_xacts.sql
new file mode 100644
index 7902152..56d5857
*** a/src/test/regress/sql/prepared_xacts.sql
--- b/src/test/regress/sql/prepared_xacts.sql
*************** SELECT * FROM pxtest3;
*** 152,158 ****
--- 152,185 ----
-- There should be no prepared transactions
SELECT gid FROM pg_prepared_xacts;
+ CREATE TABLE pxtest5 (a SERIAL);
+ INSERT INTO pxtest5 DEFAULT VALUES;
+
+ SELECT * FROM pxtest5;
+
+ BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+ INSERT INTO pxtest5 DEFAULT VALUES;
+ INSERT INTO pxtest5 DEFAULT VALUES;
+ TRUNCATE pxtest5;
+ INSERT INTO pxtest5 DEFAULT VALUES;
+ PREPARE TRANSACTION 'trunc-and-pgstat';
+
+ SELECT pg_sleep(0.5);
+ SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='pxtest5';
+
+ COMMIT PREPARED 'trunc-and-pgstat';
+
+ SELECT pg_sleep(0.5);
+ SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='pxtest5';
+
+ SELECT * FROM pxtest5;
+
-- Clean up
DROP TABLE pxtest2;
DROP TABLE pxtest3; -- will still be there if prepared xacts are disabled
DROP TABLE pxtest4;
+ DROP TABLE pxtest5;
diff --git a/src/test/regress/sql/truncate.sql b/src/test/regress/sql/truncate.sql
new file mode 100644
index a3d6f53..5840152
*** a/src/test/regress/sql/truncate.sql
--- b/src/test/regress/sql/truncate.sql
*************** SELECT * FROM truncate_a;
*** 215,217 ****
--- 215,335 ----
DROP TABLE truncate_a;
SELECT nextval('truncate_a_id1'); -- fail, seq should have been dropped
+
+ -- test effects of TRUNCATE on pgstat n_live_tup/n_dead_tup counters
+ CREATE TABLE trunc_stats_test(id serial);
+
+ CREATE TEMP TABLE prevstats AS
+ SELECT n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='trunc_stats_test';
+
+ create function wait_for_trunc_test_stats() returns prevstats as $$
+ declare
+ start_time timestamptz := clock_timestamp();
+ newstats prevstats;
+ updated bool;
+ begin
+ -- we don't want to wait forever; loop will exit after 30 seconds
+ for i in 1 .. 300 loop
+
+ SELECT INTO newstats
+ n_tup_ins, n_tup_upd, n_tup_del, n_live_tup, n_dead_tup
+ FROM pg_stat_user_tables
+ WHERE relname='trunc_stats_test';
+
+ SELECT INTO updated
+ row(p.*) <> newstats
+ FROM prevstats p;
+
+ exit when updated;
+
+ -- wait a little
+ perform pg_sleep(0.1);
+
+ -- reset stats snapshot so we can test again
+ perform pg_stat_clear_snapshot();
+
+ end loop;
+
+ IF NOT updated THEN
+ RAISE WARNING 'stats update never happened';
+ END IF;
+
+ TRUNCATE prevstats; -- what a pun
+ INSERT INTO prevstats SELECT newstats.*;
+
+ -- report time waited in postmaster log (where it won't change test output)
+ raise log 'wait_for_stats delayed % seconds',
+ extract(epoch from clock_timestamp() - start_time);
+
+ RETURN newstats;
+ end
+ $$ language plpgsql;
+
+ -- populate the table so we can check that n_live_tup is reset to 0
+ -- after truncate
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+
+ -- wait for stats collector to update
+ SELECT pg_sleep(0.5);
+ SELECT * FROM wait_for_trunc_test_stats();
+
+ TRUNCATE trunc_stats_test;
+ SELECT pg_sleep(0.5);
+ SELECT * FROM wait_for_trunc_test_stats();
+
+ -- repopulate the table
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ UPDATE trunc_stats_test SET id = id + 10 WHERE id < 6; -- UPDATE 2
+ DELETE FROM trunc_stats_test WHERE id = 6; -- DELETE 1
+
+ SELECT pg_sleep(0.5);
+ SELECT * FROM wait_for_trunc_test_stats();
+
+ BEGIN;
+ UPDATE trunc_stats_test SET id = id + 100; -- UPDATE 2
+ TRUNCATE trunc_stats_test;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ COMMIT;
+
+ SELECT pg_sleep(0.5);
+ SELECT * FROM wait_for_trunc_test_stats();
+
+ -- now to use a savepoint: this should only count 1 insert and have 1
+ -- live tuple after commit
+ BEGIN;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ SAVEPOINT p1;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ TRUNCATE trunc_stats_test;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ RELEASE SAVEPOINT p1;
+ COMMIT;
+
+ SELECT pg_sleep(0.5);
+ SELECT * FROM wait_for_trunc_test_stats();
+
+ -- rollback a savepoint: this should only count 3 inserts and have 3
+ -- live tuples after commit (and 1 dead one due to aborted subxact)
+ BEGIN;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ SAVEPOINT p1;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ TRUNCATE trunc_stats_test;
+ INSERT INTO trunc_stats_test DEFAULT VALUES;
+ ROLLBACK TO SAVEPOINT p1;
+ COMMIT;
+
+ SELECT pg_sleep(0.5);
+ SELECT * FROM wait_for_trunc_test_stats();
+
+ DROP TABLE prevstats CASCADE;
+ DROP TABLE trunc_stats_test;
--
2.1.0
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