On Thu, Jun 04, 2020 at 10:30:47AM -0700, Andres Freund wrote:
> On 2020-05-08 02:25:45 -0500, Justin Pryzby wrote:
> > Seems to me it should, at least conditionally. At least if there's a
> > function
> > scan or a relation or ..
>
> Well, the problem is that this can cause very very significant
> regressions. As in 10x slower or more. The ringbuffer can cause constant
> XLogFlush() calls (due to the lsn interlock), and the eviction from
> shared_buffers (regardless of actual available) will mean future vacuums
> etc will be much slower. I think this is likely to cause pretty
> widespread regressions on upgrades.
>
> Now, it sucks that we have this problem in the general facility that's
> supposed to be used for this kind of bulk operation. But I don't really
> see it realistic as expanding use of bulk insert strategies unless we
> have some more fundamental fixes.
I made this conditional on BEGIN BULK/SET bulk, so I'll solicit comments on
that.
postgres=# \t on \\ \set QUIET \\ VACUUM FULL t; \dt+ t \\ begin ; \timing on
\\ INSERT INTO t SELECT * FROM t; rollback; SELECT COUNT(1), usagecount FROM
pg_buffercache GROUP BY 2 ORDER BY 2;
| public | t | table | pryzbyj | 35 MB |
|Time: 9497.318 ms (00:09.497)
| 33 | 1
| 3 | 2
| 18 | 3
| 5 | 4
| 4655 | 5
| 11670 |
vs
postgres=# \t on \\ \set QUIET \\ VACUUM FULL t; \dt+ t \\ begin BULK ; \timing
on \\ INSERT INTO t SELECT * FROM t; rollback; SELECT COUNT(1), usagecount FROM
pg_buffercache GROUP BY 2 ORDER BY 2;
| public | t | table | pryzbyj | 35 MB |
|Time: 8268.780 ms (00:08.269)
| 2080 | 1
| 3 | 2
| 19 | 4
| 234 | 5
| 14048 |
And:
postgres=# begin ; \x \\ \t \\ SELECT statement_timestamp(); \o /dev/null \\
SELECT 'INSERT INTO t VALUES(0)' FROM generate_series(1,999999); \set ECHO
errors \\ \set QUIET on \\ \o \\ \gexec \\ SELECT statement_timestamp(); abort;
\x \\ SELECT COUNT(1), usagecount FROM pg_buffercache GROUP BY 2 ORDER BY 2; a
|statement_timestamp | 2020-07-12 20:31:43.717328-05
|statement_timestamp | 2020-07-12 20:36:16.692469-05
|
| 52 | 1
| 24 | 2
| 17 | 3
| 6 | 4
| 4531 | 5
| 11754 |
vs
postgres=# begin BULK ; \x \\ \t \\ SELECT statement_timestamp(); \o /dev/null
\\ SELECT 'INSERT INTO t VALUES(0)' FROM generate_series(1,999999); \set ECHO
errors \\ \set QUIET on \\ \o \\ \gexec \\ SELECT statement_timestamp(); abort;
\x \\ SELECT COUNT(1), usagecount FROM pg_buffercache GROUP BY 2 ORDER BY 2; a
|statement_timestamp | 2020-07-12 20:43:47.089538-05
|statement_timestamp | 2020-07-12 20:48:04.798138-05
|
| 4456 | 1
| 22 | 2
| 1 | 3
| 7 | 4
| 79 | 5
| 11819 |
--
Justin
>From 0362537e0f3a8496ac760574931db66c59f7c1ba Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryz...@telsasoft.com>
Date: Fri, 8 May 2020 02:17:32 -0500
Subject: [PATCH v2] Allow INSERT SELECT to use a BulkInsertState
---
src/backend/executor/nodeModifyTable.c | 23 +++++++++++++++++++++--
src/backend/parser/gram.y | 6 +++++-
src/backend/tcop/utility.c | 4 ++++
src/backend/utils/misc/guc.c | 12 +++++++++++-
src/include/executor/nodeModifyTable.h | 2 ++
src/include/nodes/execnodes.h | 2 ++
src/include/parser/kwlist.h | 1 +
7 files changed, 46 insertions(+), 4 deletions(-)
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index 20a4c474cc..5ff4a2e901 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -75,6 +75,8 @@ static ResultRelInfo *getTargetResultRelInfo(ModifyTableState *node);
static void ExecSetupChildParentMapForSubplan(ModifyTableState *mtstate);
static TupleConversionMap *tupconv_map_for_subplan(ModifyTableState *node,
int whichplan);
+/* guc */
+bool insert_in_bulk = false;
/*
* Verify that the tuples to be produced by INSERT or UPDATE match the
@@ -578,7 +580,7 @@ ExecInsert(ModifyTableState *mtstate,
table_tuple_insert_speculative(resultRelationDesc, slot,
estate->es_output_cid,
0,
- NULL,
+ NULL, /* Bulk insert not supported */
specToken);
/* insert index entries for tuple */
@@ -617,7 +619,7 @@ ExecInsert(ModifyTableState *mtstate,
/* insert the tuple normally */
table_tuple_insert(resultRelationDesc, slot,
estate->es_output_cid,
- 0, NULL);
+ 0, mtstate->bistate);
/* insert index entries for tuple */
if (resultRelInfo->ri_NumIndices > 0)
@@ -2332,6 +2334,17 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
mtstate->mt_arowmarks = (List **) palloc0(sizeof(List *) * nplans);
mtstate->mt_nplans = nplans;
+ mtstate->bistate = NULL;
+ if (operation == CMD_INSERT &&
+ node->onConflictAction != ONCONFLICT_UPDATE &&
+ node->rootResultRelIndex < 0)
+ {
+ // Plan *p = linitial(node->plans);
+ Assert(nplans == 1);
+
+ if (insert_in_bulk)
+ mtstate->bistate = GetBulkInsertState();
+ }
/* set up epqstate with dummy subplan data for the moment */
EvalPlanQualInit(&mtstate->mt_epqstate, estate, NULL, NIL, node->epqParam);
@@ -2776,6 +2789,12 @@ ExecEndModifyTable(ModifyTableState *node)
resultRelInfo);
}
+ if (node->bistate)
+ {
+ FreeBulkInsertState(node->bistate);
+ table_finish_bulk_insert((getTargetResultRelInfo(node))->ri_RelationDesc, 0);
+ }
+
/*
* Close all the partitioned tables, leaf partitions, and their indices
* and release the slot used for tuple routing, if set.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index dbb47d4982..38c4d1d1e7 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -629,7 +629,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ASSERTION ASSIGNMENT ASYMMETRIC AT ATTACH ATTRIBUTE AUTHORIZATION
BACKWARD BEFORE BEGIN_P BETWEEN BIGINT BINARY BIT
- BOOLEAN_P BOTH BY
+ BOOLEAN_P BOTH BY BULK
CACHE CALL CALLED CASCADE CASCADED CASE CAST CATALOG_P CHAIN CHAR_P
CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
@@ -9841,6 +9841,9 @@ transaction_mode_item:
| NOT DEFERRABLE
{ $$ = makeDefElem("transaction_deferrable",
makeIntConst(false, @1), @1); }
+ | BULK
+ { $$ = makeDefElem("bulk",
+ makeIntConst(true, @1), @1); }
;
/* Syntax with commas is SQL-spec, without commas is Postgres historical */
@@ -15041,6 +15044,7 @@ unreserved_keyword:
| BACKWARD
| BEFORE
| BEGIN_P
+ | BULK
| BY
| CACHE
| CALL
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 9b0c376c8c..061a022374 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -611,6 +611,10 @@ standard_ProcessUtility(PlannedStmt *pstmt,
SetPGVariable("transaction_deferrable",
list_make1(item->arg),
true);
+ else if (strcmp(item->defname, "bulk") == 0)
+ SetPGVariable("bulk_insert",
+ list_make1(item->arg),
+ true);
}
}
break;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 442e5af2b2..66a7dcf5a9 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -51,6 +51,7 @@
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "optimizer/cost.h"
+#include "executor/nodeModifyTable.h"
#include "optimizer/geqo.h"
#include "optimizer/optimizer.h"
#include "optimizer/paths.h"
@@ -917,7 +918,6 @@ static const unit_conversion time_unit_conversion_table[] =
* variable_is_guc_list_quote() in src/bin/pg_dump/dumputils.c.
*/
-
/******** option records follow ********/
static struct config_bool ConfigureNamesBool[] =
@@ -2041,6 +2041,16 @@ static struct config_bool ConfigureNamesBool[] =
NULL, NULL, NULL
},
+ {
+ {"bulk_insert", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Sets the transaction to bulk insert mode."),
+ gettext_noop("A ring buffer of limited size will be used."),
+ },
+ &insert_in_bulk,
+ false,
+ NULL, NULL, NULL
+ },
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL, NULL
diff --git a/src/include/executor/nodeModifyTable.h b/src/include/executor/nodeModifyTable.h
index 4ec4ebdabc..c0a16e6098 100644
--- a/src/include/executor/nodeModifyTable.h
+++ b/src/include/executor/nodeModifyTable.h
@@ -15,6 +15,8 @@
#include "nodes/execnodes.h"
+extern PGDLLIMPORT bool insert_in_bulk;
+
extern void ExecComputeStoredGenerated(EState *estate, TupleTableSlot *slot, CmdType cmdtype);
extern ModifyTableState *ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags);
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 0187989fd1..2679cbbb9b 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -14,6 +14,7 @@
#ifndef EXECNODES_H
#define EXECNODES_H
+#include "access/heapam.h"
#include "access/tupconvert.h"
#include "executor/instrument.h"
#include "fmgr.h"
@@ -1177,6 +1178,7 @@ typedef struct ModifyTableState
List **mt_arowmarks; /* per-subplan ExecAuxRowMark lists */
EPQState mt_epqstate; /* for evaluating EvalPlanQual rechecks */
bool fireBSTriggers; /* do we need to fire stmt triggers? */
+ BulkInsertState bistate; /* State for bulk insert like INSERT SELECT */
/*
* Slot for storing tuples in the root partitioned table's rowtype during
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 08f22ce211..80dfbac702 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -60,6 +60,7 @@ PG_KEYWORD("binary", BINARY, TYPE_FUNC_NAME_KEYWORD)
PG_KEYWORD("bit", BIT, COL_NAME_KEYWORD)
PG_KEYWORD("boolean", BOOLEAN_P, COL_NAME_KEYWORD)
PG_KEYWORD("both", BOTH, RESERVED_KEYWORD)
+PG_KEYWORD("bulk", BULK, UNRESERVED_KEYWORD)
PG_KEYWORD("by", BY, UNRESERVED_KEYWORD)
PG_KEYWORD("cache", CACHE, UNRESERVED_KEYWORD)
PG_KEYWORD("call", CALL, UNRESERVED_KEYWORD)
--
2.17.0
