diff options
Diffstat (limited to 'src/backend/optimizer/util/pathnode.c')
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 44ac5312edd..e4fd6950fad 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -17,6 +17,7 @@ #include <math.h> #include "access/htup_details.h" +#include "executor/nodeSetOp.h" #include "foreign/fdwapi.h" #include "miscadmin.h" #include "nodes/extensible.h" @@ -3461,7 +3462,7 @@ create_setop_path(PlannerInfo *root, } else { - Size hashentrysize; + Size hashtablesize; /* * In hashed mode, we must read all the input before we can emit @@ -3490,11 +3491,12 @@ create_setop_path(PlannerInfo *root, /* * Also disable if it doesn't look like the hashtable will fit into - * hash_mem. + * hash_mem. (Note: reject on equality, to ensure that an estimate of + * SIZE_MAX disables hashing regardless of the hash_mem limit.) */ - hashentrysize = MAXALIGN(leftpath->pathtarget->width) + - MAXALIGN(SizeofMinimalTupleHeader); - if (hashentrysize * numGroups > get_hash_memory_limit()) + hashtablesize = EstimateSetOpHashTableSpace(numGroups, + leftpath->pathtarget->width); + if (hashtablesize >= get_hash_memory_limit()) pathnode->path.disabled_nodes++; } pathnode->path.rows = outputRows; |