diff options
| author | Thomas Munro <tmunro@postgresql.org> | 2020-09-19 11:28:34 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2020-09-19 11:40:39 +1200 |
| commit | be0a6666656ec3f68eb7d8e7abab5139fcd47012 (patch) | |
| tree | 35ffd7aa1145d6b33d51c50d227a20ab410cdf77 /src/include/utils | |
| parent | 06a7c3154f5bfad65549810cc84f0e3a77b408bf (diff) | |
Remove large fill factor support from dynahash.c.
Since ancient times we have had support for a fill factor (maximum load
factor) to be set for a dynahash hash table, but:
1. It was an integer, whereas for in-memory hash tables interesting
load factor targets are probably somewhere near the 0.75-1.0 range.
2. It was implemented in a way that performed an expensive division
operation that regularly showed up in profiles.
3. We are not aware of anyone ever having used a non-default value.
Therefore, remove support, effectively fixing it at 1.
Author: Jakub Wartak <Jakub.Wartak@tomtom.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/VI1PR0701MB696044FC35013A96FECC7AC8F62D0%40VI1PR0701MB6960.eurprd07.prod.outlook.com
Diffstat (limited to 'src/include/utils')
| -rw-r--r-- | src/include/utils/hsearch.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/src/include/utils/hsearch.h b/src/include/utils/hsearch.h index f1deb9beab0..bebf89b3c45 100644 --- a/src/include/utils/hsearch.h +++ b/src/include/utils/hsearch.h @@ -68,7 +68,6 @@ typedef struct HASHCTL long ssize; /* segment size */ long dsize; /* (initial) directory size */ long max_dsize; /* limit to dsize if dir size is limited */ - long ffactor; /* fill factor */ Size keysize; /* hash key length in bytes */ Size entrysize; /* total user element size in bytes */ HashValueFunc hash; /* hash function */ @@ -83,7 +82,6 @@ typedef struct HASHCTL #define HASH_PARTITION 0x0001 /* Hashtable is used w/partitioned locking */ #define HASH_SEGMENT 0x0002 /* Set segment size */ #define HASH_DIRSIZE 0x0004 /* Set directory size (initial and max) */ -#define HASH_FFACTOR 0x0008 /* Set fill factor */ #define HASH_ELEM 0x0010 /* Set keysize and entrysize */ #define HASH_BLOBS 0x0020 /* Select support functions for binary keys */ #define HASH_FUNCTION 0x0040 /* Set user defined hash function */ |