diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index c910863..b891327 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -2050,12 +2050,27 @@ heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid, tup->t_data->t_infomask &= ~(HEAP_XACT_MASK); tup->t_data->t_infomask2 &= ~(HEAP2_XACT_MASK); tup->t_data->t_infomask |= HEAP_XMAX_INVALID; - HeapTupleHeaderSetXmin(tup->t_data, xid); HeapTupleHeaderSetCmin(tup->t_data, cid); HeapTupleHeaderSetXmax(tup->t_data, 0); /* for cleanliness */ tup->t_tableOid = RelationGetRelid(relation); /* + * If we are inserting into a new relation invisible as yet to other + * backends and our session has no prior snapshots and no ready portals + * then we can also set the hint bit for the rows we are inserting. The + * last two restrictions ensure that HeapTupleSatisfiesMVCC() gives + * the right answer if the current transaction inspects the data after + * we load it. + */ + if (options & HEAP_INSERT_HINT_XMIN) + { + tup->t_data->t_infomask |= HEAP_XMIN_COMMITTED; + HeapTupleHeaderSetXmin(tup->t_data, FrozenTransactionId); + } + else + HeapTupleHeaderSetXmin(tup->t_data, xid); + + /* * If the new tuple is too big for storage or contains already toasted * out-of-line attributes from some other relation, invoke the toaster. */ diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c index 110480f..a34f072 100644 --- a/src/backend/commands/copy.c +++ b/src/backend/commands/copy.c @@ -43,6 +43,7 @@ #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/memutils.h" +#include "utils/portal.h" #include "utils/rel.h" #include "utils/snapmgr.h" @@ -1922,6 +1923,21 @@ CopyFrom(CopyState cstate) hi_options |= HEAP_INSERT_SKIP_FSM; if (!XLogIsNeeded()) hi_options |= HEAP_INSERT_SKIP_WAL; + + if (ThereAreNoPriorRegisteredSnapshots() && + ThereAreNoReadyPortals()) + { + SubTransactionId currxid = GetCurrentSubTransactionId(); + + /* + * If the relfilenode has been created in this subtransaction + * then we can further optimise the data load by setting hint + * bits and pre-freezing tuples. + */ + if (cstate->rel->rd_createSubid == currxid || + cstate->rel->rd_newRelfilenodeSubid == currxid) + hi_options |= HEAP_INSERT_HINT_XMIN; + } } /* diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c index cfb73c1..24075db 100644 --- a/src/backend/utils/mmgr/portalmem.c +++ b/src/backend/utils/mmgr/portalmem.c @@ -1055,3 +1055,22 @@ pg_cursor(PG_FUNCTION_ARGS) return (Datum) 0; } + +bool +ThereAreNoReadyPortals(void) +{ + HASH_SEQ_STATUS status; + PortalHashEnt *hentry; + + hash_seq_init(&status, PortalHashTable); + + while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL) + { + Portal portal = hentry->portal; + + if (portal->status == PORTAL_READY) + return false; + } + + return true; +} diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c index 5aebbd1..5d9e3bf 100644 --- a/src/backend/utils/time/snapmgr.c +++ b/src/backend/utils/time/snapmgr.c @@ -1183,3 +1183,12 @@ DeleteAllExportedSnapshotFiles(void) FreeDir(s_dir); } + +bool +ThereAreNoPriorRegisteredSnapshots(void) +{ + if (RegisteredSnapshots <= 1) + return true; + + return false; +} diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h index fa38803..0381785 100644 --- a/src/include/access/heapam.h +++ b/src/include/access/heapam.h @@ -26,6 +26,7 @@ /* "options" flag bits for heap_insert */ #define HEAP_INSERT_SKIP_WAL 0x0001 #define HEAP_INSERT_SKIP_FSM 0x0002 +#define HEAP_INSERT_HINT_XMIN 0x0004 typedef struct BulkInsertStateData *BulkInsertState; diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h index 4833942..bd2b133 100644 --- a/src/include/utils/portal.h +++ b/src/include/utils/portal.h @@ -219,5 +219,6 @@ extern void PortalDefineQuery(Portal portal, extern Node *PortalListGetPrimaryStmt(List *stmts); extern void PortalCreateHoldStore(Portal portal); extern void PortalHashTableDeleteAll(void); +extern bool ThereAreNoReadyPortals(void); #endif /* PORTAL_H */ diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h index f195981..789b72e 100644 --- a/src/include/utils/snapmgr.h +++ b/src/include/utils/snapmgr.h @@ -46,5 +46,6 @@ extern Datum pg_export_snapshot(PG_FUNCTION_ARGS); extern void ImportSnapshot(const char *idstr); extern bool XactHasExportedSnapshots(void); extern void DeleteAllExportedSnapshotFiles(void); +extern bool ThereAreNoPriorRegisteredSnapshots(void); #endif /* SNAPMGR_H */ diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out index 8e2bc0c..b9626e5 100644 --- a/src/test/regress/expected/copy2.out +++ b/src/test/regress/expected/copy2.out @@ -239,6 +239,70 @@ a\. \.b c\.d "\." +CREATE TABLE vistest (LIKE testeoc); +BEGIN; +TRUNCATE vistest; +COPY vistest FROM stdin CSV; +SELECT * FROM vistest; + a +--- + a + b + c +(3 rows) + +SAVEPOINT s1; +TRUNCATE vistest; +COPY vistest FROM stdin CSV; +SELECT * FROM vistest; + a +--- + d + e + f +(3 rows) + +SAVEPOINT s2; +TRUNCATE vistest; +SAVEPOINT s3; +COPY vistest FROM stdin CSV; +SELECT * FROM vistest; + a +--- + j + k + l +(3 rows) + +ROLLBACK TO SAVEPOINT s2; +SELECT * FROM vistest; + a +--- + d + e + f +(3 rows) + +TRUNCATE vistest; +COPY vistest FROM stdin CSV; +SELECT * FROM vistest; + a +--- + x + y + z +(3 rows) + +COMMIT; +SELECT * FROM vistest; + a +--- + x + y + z +(3 rows) + +DROP TABLE vistest; DROP TABLE x, y; DROP FUNCTION fn_x_before(); DROP FUNCTION fn_x_after(); diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql index 6322c8f..3d2c376 100644 --- a/src/test/regress/sql/copy2.sql +++ b/src/test/regress/sql/copy2.sql @@ -164,6 +164,45 @@ c\.d COPY testeoc TO stdout CSV; +CREATE TABLE vistest (LIKE testeoc); +BEGIN; +TRUNCATE vistest; +COPY vistest FROM stdin CSV; +a +b +c +\. +SELECT * FROM vistest; +SAVEPOINT s1; +TRUNCATE vistest; +COPY vistest FROM stdin CSV; +d +e +f +\. +SELECT * FROM vistest; +SAVEPOINT s2; +TRUNCATE vistest; +SAVEPOINT s3; +COPY vistest FROM stdin CSV; +j +k +l +\. +SELECT * FROM vistest; +ROLLBACK TO SAVEPOINT s2; +SELECT * FROM vistest; +TRUNCATE vistest; +COPY vistest FROM stdin CSV; +x +y +z +\. +SELECT * FROM vistest; +COMMIT; +SELECT * FROM vistest; + +DROP TABLE vistest; DROP TABLE x, y; DROP FUNCTION fn_x_before(); DROP FUNCTION fn_x_after();