diff options
| -rw-r--r-- | src/backend/executor/spi.c | 32 | ||||
| -rw-r--r-- | src/backend/utils/adt/ri_triggers.c | 32 | ||||
| -rw-r--r-- | src/backend/utils/cache/plancache.c | 40 | ||||
| -rw-r--r-- | src/include/executor/spi.h | 3 | ||||
| -rw-r--r-- | src/include/utils/plancache.h | 3 |
5 files changed, 103 insertions, 7 deletions
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c index 443ee57e682..302109f24f2 100644 --- a/src/backend/executor/spi.c +++ b/src/backend/executor/spi.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.197 2008/07/18 20:26:06 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.198 2008/09/15 23:37:39 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1368,6 +1368,36 @@ SPI_is_cursor_plan(SPIPlanPtr plan) } /* + * SPI_plan_is_valid --- test whether a SPI plan is currently valid + * (that is, not marked as being in need of revalidation). + * + * See notes for CachedPlanIsValid before using this. + */ +bool +SPI_plan_is_valid(SPIPlanPtr plan) +{ + Assert(plan->magic == _SPI_PLAN_MAGIC); + if (plan->saved) + { + ListCell *lc; + + foreach(lc, plan->plancache_list) + { + CachedPlanSource *plansource = (CachedPlanSource *) lfirst(lc); + + if (!CachedPlanIsValid(plansource)) + return false; + } + return true; + } + else + { + /* An unsaved plan is assumed valid for its (short) lifetime */ + return true; + } +} + +/* * SPI_result_code_string --- convert any SPI return code to a string * * This is often useful in error messages. Most callers will probably diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c index 7f564e09fa0..8fe29ea260b 100644 --- a/src/backend/utils/adt/ri_triggers.c +++ b/src/backend/utils/adt/ri_triggers.c @@ -15,7 +15,7 @@ * * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * - * $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.109 2008/05/19 04:14:24 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.110 2008/09/15 23:37:39 tgl Exp $ * * ---------- */ @@ -3615,6 +3615,7 @@ static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key) { RI_QueryHashEntry *entry; + SPIPlanPtr plan; /* * On the first call initialize the hashtable @@ -3630,7 +3631,30 @@ ri_FetchPreparedPlan(RI_QueryKey *key) HASH_FIND, NULL); if (entry == NULL) return NULL; - return entry->plan; + + /* + * Check whether the plan is still valid. If it isn't, we don't want + * to simply rely on plancache.c to regenerate it; rather we should + * start from scratch and rebuild the query text too. This is to cover + * cases such as table/column renames. We depend on the plancache + * machinery to detect possible invalidations, though. + * + * CAUTION: this check is only trustworthy if the caller has already + * locked both FK and PK rels. + */ + plan = entry->plan; + if (plan && SPI_plan_is_valid(plan)) + return plan; + + /* + * Otherwise we might as well flush the cached plan now, to free a + * little memory space before we make a new one. + */ + entry->plan = NULL; + if (plan) + SPI_freeplan(plan); + + return NULL; } @@ -3653,11 +3677,13 @@ ri_HashPreparedPlan(RI_QueryKey *key, SPIPlanPtr plan) ri_InitHashTables(); /* - * Add the new plan. + * Add the new plan. We might be overwriting an entry previously + * found invalid by ri_FetchPreparedPlan. */ entry = (RI_QueryHashEntry *) hash_search(ri_query_cache, (void *) key, HASH_ENTER, &found); + Assert(!found || entry->plan == NULL); entry->plan = plan; } diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c index bf1adf16ecc..48addf3f539 100644 --- a/src/backend/utils/cache/plancache.c +++ b/src/backend/utils/cache/plancache.c @@ -35,7 +35,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.21 2008/09/09 18:58:08 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.22 2008/09/15 23:37:39 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -572,6 +572,44 @@ ReleaseCachedPlan(CachedPlan *plan, bool useResOwner) } /* + * CachedPlanIsValid: test whether the plan within a CachedPlanSource is + * currently valid (that is, not marked as being in need of revalidation). + * + * This result is only trustworthy (ie, free from race conditions) if + * the caller has acquired locks on all the relations used in the plan. + */ +bool +CachedPlanIsValid(CachedPlanSource *plansource) +{ + CachedPlan *plan; + + /* Validity check that we were given a CachedPlanSource */ + Assert(list_member_ptr(cached_plans_list, plansource)); + + plan = plansource->plan; + if (plan && !plan->dead) + { + /* + * Plan must have positive refcount because it is referenced by + * plansource; so no need to fear it disappears under us here. + */ + Assert(plan->refcount > 0); + + /* + * Although we don't want to acquire locks here, it still seems + * useful to check for expiration of a transient plan. + */ + if (TransactionIdIsValid(plan->saved_xmin) && + !TransactionIdEquals(plan->saved_xmin, TransactionXmin)) + plan->dead = true; + else + return true; + } + + return false; +} + +/* * AcquireExecutorLocks: acquire locks needed for execution of a fully-planned * cached plan; or release them if acquire is false. */ diff --git a/src/include/executor/spi.h b/src/include/executor/spi.h index 9d3f65b8cf0..82e9757f9d1 100644 --- a/src/include/executor/spi.h +++ b/src/include/executor/spi.h @@ -6,7 +6,7 @@ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/executor/spi.h,v 1.66 2008/04/01 03:09:30 tgl Exp $ + * $PostgreSQL: pgsql/src/include/executor/spi.h,v 1.67 2008/09/15 23:37:40 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -118,6 +118,7 @@ extern int SPI_freeplan(SPIPlanPtr plan); extern Oid SPI_getargtypeid(SPIPlanPtr plan, int argIndex); extern int SPI_getargcount(SPIPlanPtr plan); extern bool SPI_is_cursor_plan(SPIPlanPtr plan); +extern bool SPI_plan_is_valid(SPIPlanPtr plan); extern const char *SPI_result_code_string(int code); extern HeapTuple SPI_copytuple(HeapTuple tuple); diff --git a/src/include/utils/plancache.h b/src/include/utils/plancache.h index e19da85e93a..e84a3e742bd 100644 --- a/src/include/utils/plancache.h +++ b/src/include/utils/plancache.h @@ -8,7 +8,7 @@ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/utils/plancache.h,v 1.13 2008/09/09 18:58:09 tgl Exp $ + * $PostgreSQL: pgsql/src/include/utils/plancache.h,v 1.14 2008/09/15 23:37:40 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -109,6 +109,7 @@ extern void DropCachedPlan(CachedPlanSource *plansource); extern CachedPlan *RevalidateCachedPlan(CachedPlanSource *plansource, bool useResOwner); extern void ReleaseCachedPlan(CachedPlan *plan, bool useResOwner); +extern bool CachedPlanIsValid(CachedPlanSource *plansource); extern TupleDesc PlanCacheComputeResultDesc(List *stmt_list); extern void ResetPlanCache(void); |