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Revert "Fix an O(N^2) problem in foreign key references".

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Commit 5ddc72887a012f6a8b85707ef27d85c274faf53d does not actually work
because it will happily blow away ri_constraint_cache entries that are
in active use in outer call levels.  In any case, it's a very ugly,
brute-force solution to the problem of limiting the cache size.
Revert until it can be redesigned.
This commit is contained in:
Tom Lane 2015-09-15 11:08:56 -04:00
parent ca445043e7
commit be136b2430
1 changed files with 7 additions and 39 deletions
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46
src/backend/utils/adt/ri_triggers.c
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@ -182,7 +182,6 @@ typedef struct RI_CompareHashEntry
* ----------
*/
static HTAB *ri_constraint_cache = NULL;
static long ri_constraint_cache_seq_count = 0;
static HTAB *ri_query_cache = NULL;
static HTAB *ri_compare_cache = NULL;
@ -215,7 +214,6 @@ static bool ri_KeysEqual(Relation rel, HeapTuple oldtup, HeapTuple newtup,
static bool ri_AttributesEqual(Oid eq_opr, Oid typeid,
Datum oldvalue, Datum newvalue);
static void ri_InitConstraintCache(void);
static void ri_InitHashTables(void);
static void InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue);
static SPIPlanPtr ri_FetchPreparedPlan(RI_QueryKey *key);
@ -2934,20 +2932,6 @@ InvalidateConstraintCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
Assert(ri_constraint_cache != NULL);
/*
* Prevent an O(N^2) problem when creating large amounts of foreign
* key constraints with ALTER TABLE, like it happens at the end of
* a pg_dump with hundred-thousands of tables having references.
*/
ri_constraint_cache_seq_count += hash_get_num_entries(ri_constraint_cache);
if (ri_constraint_cache_seq_count > 1000000)
{
hash_destroy(ri_constraint_cache);
ri_InitConstraintCache();
ri_constraint_cache_seq_count = 0;
return;
}
hash_seq_init(&status, ri_constraint_cache);
while ((hentry = (RI_ConstraintInfo *) hash_seq_search(&status)) != NULL)
{
@ -3341,28 +3325,6 @@ ri_NullCheck(HeapTuple tup,
}
/* ----------
* ri_InitConstraintCache
*
* Initialize ri_constraint_cache when new or being rebuilt.
*
* This needs to be done from two places, so split it out to prevent drift.
* ----------
*/
static void
ri_InitConstraintCache(void)
{
HASHCTL ctl;
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(RI_ConstraintInfo);
ctl.hash = oid_hash;
ri_constraint_cache = hash_create("RI constraint cache",
RI_INIT_CONSTRAINTHASHSIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
}
/* ----------
* ri_InitHashTables -
*
@ -3374,7 +3336,13 @@ ri_InitHashTables(void)
{
HASHCTL ctl;
ri_InitConstraintCache();
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(RI_ConstraintInfo);
ctl.hash = oid_hash;
ri_constraint_cache = hash_create("RI constraint cache",
RI_INIT_CONSTRAINTHASHSIZE,
&ctl, HASH_ELEM | HASH_FUNCTION);
/* Arrange to flush cache on pg_constraint changes */
CacheRegisterSyscacheCallback(CONSTROID,