diff options
Diffstat (limited to 'src/backend/executor/nodeMemoize.c')
| -rw-r--r-- | src/backend/executor/nodeMemoize.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/src/backend/executor/nodeMemoize.c b/src/backend/executor/nodeMemoize.c index 0722e47777b..18870f10e11 100644 --- a/src/backend/executor/nodeMemoize.c +++ b/src/backend/executor/nodeMemoize.c @@ -278,11 +278,14 @@ MemoizeHash_equal(struct memoize_hash *tb, const MemoizeKey *key1, } /* - * Initialize the hash table to empty. + * Initialize the hash table to empty. The MemoizeState's hashtable field + * must point to NULL. */ static void build_hash_table(MemoizeState *mstate, uint32 size) { + Assert(mstate->hashtable == NULL); + /* Make a guess at a good size when we're not given a valid size. */ if (size == 0) size = 1024; @@ -400,8 +403,10 @@ remove_cache_entry(MemoizeState *mstate, MemoizeEntry *entry) static void cache_purge_all(MemoizeState *mstate) { - uint64 evictions = mstate->hashtable->members; - PlanState *pstate = (PlanState *) mstate; + uint64 evictions = 0; + + if (mstate->hashtable != NULL) + evictions = mstate->hashtable->members; /* * Likely the most efficient way to remove all items is to just reset the @@ -410,8 +415,8 @@ cache_purge_all(MemoizeState *mstate) */ MemoryContextReset(mstate->tableContext); - /* Make the hash table the same size as the original size */ - build_hash_table(mstate, ((Memoize *) pstate->plan)->est_entries); + /* NULLify so we recreate the table on the next call */ + mstate->hashtable = NULL; /* reset the LRU list */ dlist_init(&mstate->lru_list); @@ -707,6 +712,10 @@ ExecMemoize(PlanState *pstate) Assert(node->entry == NULL); + /* first call? we'll need a hash table. */ + if (unlikely(node->hashtable == NULL)) + build_hash_table(node, ((Memoize *) pstate->plan)->est_entries); + /* * We're only ever in this state for the first call of the * scan. Here we have a look to see if we've already seen the @@ -1051,8 +1060,11 @@ ExecInitMemoize(Memoize *node, EState *estate, int eflags) /* Zero the statistics counters */ memset(&mstate->stats, 0, sizeof(MemoizeInstrumentation)); - /* Allocate and set up the actual cache */ - build_hash_table(mstate, node->est_entries); + /* + * Because it may require a large allocation, we delay building of the + * hash table until executor run. + */ + mstate->hashtable = NULL; return mstate; } @@ -1062,6 +1074,7 @@ ExecEndMemoize(MemoizeState *node) { #ifdef USE_ASSERT_CHECKING /* Validate the memory accounting code is correct in assert builds. */ + if (node->hashtable != NULL) { int count; uint64 mem = 0; |