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Repair RI trigger visibility problems (this time for sure ;-)) per recent

discussion on pgsql-hackers: in READ COMMITTED mode we just have to force
a QuerySnapshot update in the trigger, but in SERIALIZABLE mode we have
to run the scan under a current snapshot and then complain if any rows
would be updated/deleted that are not visible in the transaction snapshot.
This commit is contained in:
Tom Lane
2003-10-01 21:30:53 +00:00
parent 6099bc03f3
commit 55d85f42a8
15 changed files with 210 additions and 84 deletions

View File

@ -17,7 +17,7 @@
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
*
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.60 2003/09/29 00:05:25 petere Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.61 2003/10/01 21:30:52 tgl Exp $
*
* ----------
*/
@ -157,6 +157,7 @@ static void *ri_PlanCheck(const char *querystr, int nargs, Oid *argtypes,
static bool ri_PerformCheck(RI_QueryKey *qkey, void *qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
bool detectNewRows,
int expect_OK, const char *constrname);
static void ri_ExtractValues(RI_QueryKey *qkey, int key_idx,
Relation rel, HeapTuple tuple,
@ -276,6 +277,7 @@ RI_FKey_check(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
NULL, NULL,
false,
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -433,6 +435,7 @@ RI_FKey_check(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
NULL, new_row,
false,
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -594,6 +597,7 @@ ri_Check_Pk_Match(Relation pk_rel, Relation fk_rel,
result = ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* treat like update */
SPI_OK_SELECT, NULL);
if (SPI_finish() != SPI_OK_FINISH)
@ -752,6 +756,7 @@ RI_FKey_noaction_del(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -942,6 +947,7 @@ RI_FKey_noaction_upd(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -1102,6 +1108,7 @@ RI_FKey_cascade_del(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_DELETE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -1285,6 +1292,7 @@ RI_FKey_cascade_upd(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, new_row,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -1453,6 +1461,7 @@ RI_FKey_restrict_del(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -1633,6 +1642,7 @@ RI_FKey_restrict_upd(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -1802,6 +1812,7 @@ RI_FKey_setnull_del(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -2019,6 +2030,7 @@ RI_FKey_setnull_upd(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -2188,6 +2200,7 @@ RI_FKey_setdefault_del(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -2392,6 +2405,7 @@ RI_FKey_setdefault_upd(PG_FUNCTION_ARGS)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
@ -2788,11 +2802,13 @@ static bool
ri_PerformCheck(RI_QueryKey *qkey, void *qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
bool detectNewRows,
int expect_OK, const char *constrname)
{
Relation query_rel,
source_rel;
int key_idx;
bool useCurrentSnapshot;
int limit;
int spi_result;
AclId save_uid;
@ -2842,9 +2858,25 @@ ri_PerformCheck(RI_QueryKey *qkey, void *qplan,
vals, nulls);
}
/* Switch to proper UID to perform check as */
save_uid = GetUserId();
SetUserId(RelationGetForm(query_rel)->relowner);
/*
* In READ COMMITTED mode, we just need to make sure the regular query
* snapshot is up-to-date, and we will see all rows that could be
* interesting. In SERIALIZABLE mode, we can't update the regular query
* snapshot. If the caller passes detectNewRows == false then it's okay
* to do the query with the transaction snapshot; otherwise we tell the
* executor to force a current snapshot (and error out if it finds any
* rows under current snapshot that wouldn't be visible per the
* transaction snapshot).
*/
if (XactIsoLevel == XACT_SERIALIZABLE)
{
useCurrentSnapshot = detectNewRows;
}
else
{
SetQuerySnapshot();
useCurrentSnapshot = false;
}
/*
* If this is a select query (e.g., for a 'no action' or 'restrict'
@ -2854,19 +2886,20 @@ ri_PerformCheck(RI_QueryKey *qkey, void *qplan,
*/
limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
/*
* Run the plan, using SnapshotNow time qual rules so that we can see
* all committed tuples, even those committed after our own transaction
* or query started.
*/
spi_result = SPI_execp_now(qplan, vals, nulls, limit);
/* Switch to proper UID to perform check as */
save_uid = GetUserId();
SetUserId(RelationGetForm(query_rel)->relowner);
/* Finally we can run the query. */
spi_result = SPI_execp_current(qplan, vals, nulls,
useCurrentSnapshot, limit);
/* Restore UID */
SetUserId(save_uid);
/* Check result */
if (spi_result < 0)
elog(ERROR, "SPI_execp_now returned %d", spi_result);
elog(ERROR, "SPI_execp_current returned %d", spi_result);
if (expect_OK >= 0 && spi_result != expect_OK)
ri_ReportViolation(qkey, constrname ? constrname : "",