open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Revert "Handle better implicit transaction state of pipeline mode"

Browse Source 
This reverts commit d77f91214f on all stable branches, due to concerns
regarding the compatility side effects this could create in a minor
release.  The change still exists on HEAD.

Discussion: https://postgr.es/m/CA+TgmoZqRgeFTg4+Yf_CMRRXiHuNz1u6ZC4FvVk+rxw0RmOPnw@mail.gmail.com
Backpatch-through: 13
REL_15_STABLE
Michael Paquier 10 months ago
parent 3bbfa2ef78
commit 6d1183515e
4 changed files with 23 additions and 184 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 21
      doc/src/sgml/protocol.sgml
  2. 13
      src/backend/access/transam/xact.c
  3. 18
      src/backend/tcop/postgres.c
  4. 155
      src/bin/pgbench/t/001_pgbench_with_server.pl

21
doc/src/sgml/protocol.sgml
Unescape View File

@ -1088,17 +1088,16 @@ SELCT 1/0;<!-- this typo is intentional -->
<para>
If the client has not issued an explicit <command>BEGIN</command>,
then an implicit transaction block is started and each Sync ordinarily
causes an implicit <command>COMMIT</command> if the preceding step(s)
succeeded, or an implicit <command>ROLLBACK</command> if they failed.
This implicit transaction block will only be detected by the server
when the first command ends without a sync. There are a few DDL
commands (such as <command>CREATE DATABASE</command>) that cannot be
executed inside a transaction block. If one of these is executed in a
pipeline, it will fail unless it is the first command after a Sync.
Furthermore, upon success it will force an immediate commit to preserve
database consistency. Thus a Sync immediately following one of these
commands has no effect except to respond with ReadyForQuery.
then each Sync ordinarily causes an implicit <command>COMMIT</command>
if the preceding step(s) succeeded, or an
implicit <command>ROLLBACK</command> if they failed. However, there
are a few DDL commands (such as <command>CREATE DATABASE</command>)
that cannot be executed inside a transaction block. If one of
these is executed in a pipeline, it will fail unless it is the first
command in the pipeline. Furthermore, upon success it will force an
immediate commit to preserve database consistency. Thus a Sync
immediately following one of these commands has no effect except to
respond with ReadyForQuery.
</para>
<para>

13
src/backend/access/transam/xact.c
Unescape View File

@ -3489,6 +3489,16 @@ PreventInTransactionBlock(bool isTopLevel, const char *stmtType)
errmsg("%s cannot run inside a subtransaction",
stmtType)));
/*
* inside a pipeline that has started an implicit transaction?
*/
if (MyXactFlags & XACT_FLAGS_PIPELINING)
ereport(ERROR,
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
/* translator: %s represents an SQL statement name */
errmsg("%s cannot be executed within a pipeline",
stmtType)));
/*
* inside a function call?
*/
@ -3600,6 +3610,9 @@ IsInTransactionBlock(bool isTopLevel)
if (IsSubTransaction())
return true;
if (MyXactFlags & XACT_FLAGS_PIPELINING)
return true;
if (!isTopLevel)
return true;

18
src/backend/tcop/postgres.c
Unescape View File

@ -2746,17 +2746,6 @@ start_xact_command(void)
xact_started = true;
}
else if (MyXactFlags & XACT_FLAGS_PIPELINING)
{
/*
* When the first Execute message is completed, following commands
* will be done in an implicit transaction block created via
* pipelining. The transaction state needs to be updated to an
* implicit block if we're not already in a transaction block (like
* one started by an explicit BEGIN).
*/
BeginImplicitTransactionBlock();
}
/*
* Start statement timeout if necessary. Note that this'll intentionally
@ -4876,13 +4865,6 @@ PostgresMain(const char *dbname, const char *username)
case 'S': /* sync */
pq_getmsgend(&input_message);
/*
* If pipelining was used, we may be in an implicit
* transaction block. Close it before calling
* finish_xact_command.
*/
EndImplicitTransactionBlock();
finish_xact_command();
send_ready_for_query = true;
break;

155
src/bin/pgbench/t/001_pgbench_with_server.pl
Unescape View File

@ -897,161 +897,6 @@ $node->pgbench(
}
});
# Try SET LOCAL as first pipeline command. This succeeds and the first
# command is not executed inside an implicit transaction block, causing
# a WARNING.
$node->pgbench(
'-t 1 -n -M extended',
0,
[],
[qr{WARNING: SET LOCAL can only be used in transaction blocks}],
'SET LOCAL outside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_set_local_1' => q{
\startpipeline
SET LOCAL statement_timeout='1h';
\endpipeline
}
});
# Try SET LOCAL as second pipeline command. This succeeds and the second
# command does not cause a WARNING to be generated.
$node->pgbench(
'-t 1 -n -M extended',
0,
[],
[qr{^$}],
'SET LOCAL inside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_set_local_2' => q{
\startpipeline
SELECT 1;
SET LOCAL statement_timeout='1h';
\endpipeline
}
});
# Try REINDEX CONCURRENTLY as first pipeline command. This succeeds
# as the first command is outside the implicit transaction block of
# a pipeline.
$node->pgbench(
'-t 1 -n -M extended',
0,
[],
[],
'REINDEX CONCURRENTLY outside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_reindex_1' => q{
\startpipeline
REINDEX TABLE CONCURRENTLY pgbench_accounts;
SELECT 1;
\endpipeline
}
});
# Try REINDEX CONCURRENTLY as second pipeline command. This fails
# as the second command is inside an implicit transaction block.
$node->pgbench(
'-t 1 -n -M extended',
2,
[],
[],
'error: REINDEX CONCURRENTLY inside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_reindex_2' => q{
\startpipeline
SELECT 1;
REINDEX TABLE CONCURRENTLY pgbench_accounts;
\endpipeline
}
});
# Try VACUUM as first pipeline command. Like REINDEX CONCURRENTLY, this
# succeeds as this is outside the implicit transaction block of a pipeline.
$node->pgbench(
'-t 1 -n -M extended',
0,
[],
[],
'VACUUM outside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_vacuum_1' => q{
\startpipeline
VACUUM pgbench_accounts;
\endpipeline
}
});
# Try VACUUM as second pipeline command. This fails, as the second command
# of a pipeline is inside an implicit transaction block.
$node->pgbench(
'-t 1 -n -M extended',
2,
[],
[],
'error: VACUUM inside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_vacuum_2' => q{
\startpipeline
SELECT 1;
VACUUM pgbench_accounts;
\endpipeline
}
});
# Try subtransactions in a pipeline. These are forbidden in implicit
# transaction blocks.
$node->pgbench(
'-t 1 -n -M extended',
2,
[],
[],
'error: subtransactions not allowed in pipeline',
{
'001_pgbench_pipeline_subtrans' => q{
\startpipeline
SAVEPOINT a;
SELECT 1;
ROLLBACK TO SAVEPOINT a;
SELECT 2;
\endpipeline
}
});
# Try LOCK TABLE as first pipeline command. This fails as LOCK is outside
# an implicit transaction block.
$node->pgbench(
'-t 1 -n -M extended',
2,
[],
[],
'error: LOCK TABLE outside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_lock_1' => q{
\startpipeline
LOCK pgbench_accounts;
SELECT 1;
\endpipeline
}
});
# Try LOCK TABLE as second pipeline command. This succeeds as LOCK is inside
# an implicit transaction block.
$node->pgbench(
'-t 1 -n -M extended',
0,
[],
[],
'LOCK TABLE inside implicit transaction block of pipeline',
{
'001_pgbench_pipeline_lock_2' => q{
\startpipeline
SELECT 1;
LOCK pgbench_accounts;
\endpipeline
}
});
# Working \startpipeline in prepared query mode with serializable
$node->pgbench(
'-c4 -t 10 -n -M prepared',

Write Preview
Loading…
Cancel
Save