From 81c5e46c490e2426db243eada186995da5bb0ba7 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 31 Aug 2017 22:21:21 -0400 Subject: Introduce 64-bit hash functions with a 64-bit seed. This will be useful for hash partitioning, which needs a way to seed the hash functions to avoid problems such as a hash index on a hash partitioned table clumping all values into a small portion of the bucket space; it's also useful for anything that wants a 64-bit hash value rather than a 32-bit hash value. Just in case somebody wants a 64-bit hash value that is compatible with the existing 32-bit hash values, make the low 32-bits of the 64-bit hash value match the 32-bit hash value when the seed is 0. Robert Haas and Amul Sul Discussion: http://postgr.es/m/CA+Tgmoafx2yoJuhCQQOL5CocEi-w_uG4S2xT0EtgiJnPGcHW3g@mail.gmail.com --- src/include/utils/jsonb.h | 2 ++ src/include/utils/typcache.h | 4 ++++ 2 files changed, 6 insertions(+) (limited to 'src/include/utils') diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h index ea9dd17540d..24f491663bb 100644 --- a/src/include/utils/jsonb.h +++ b/src/include/utils/jsonb.h @@ -370,6 +370,8 @@ extern Jsonb *JsonbValueToJsonb(JsonbValue *val); extern bool JsonbDeepContains(JsonbIterator **val, JsonbIterator **mContained); extern void JsonbHashScalarValue(const JsonbValue *scalarVal, uint32 *hash); +extern void JsonbHashScalarValueExtended(const JsonbValue *scalarVal, + uint64 *hash, uint64 seed); /* jsonb.c support functions */ extern char *JsonbToCString(StringInfo out, JsonbContainer *in, diff --git a/src/include/utils/typcache.h b/src/include/utils/typcache.h index c12631dafe2..b4f75921625 100644 --- a/src/include/utils/typcache.h +++ b/src/include/utils/typcache.h @@ -56,6 +56,7 @@ typedef struct TypeCacheEntry Oid gt_opr; /* the greater-than operator */ Oid cmp_proc; /* the btree comparison function */ Oid hash_proc; /* the hash calculation function */ + Oid hash_extended_proc; /* the extended hash calculation function */ /* * Pre-set-up fmgr call info for the equality operator, the btree @@ -67,6 +68,7 @@ typedef struct TypeCacheEntry FmgrInfo eq_opr_finfo; FmgrInfo cmp_proc_finfo; FmgrInfo hash_proc_finfo; + FmgrInfo hash_extended_proc_finfo; /* * Tuple descriptor if it's a composite type (row type). NULL if not @@ -120,6 +122,8 @@ typedef struct TypeCacheEntry #define TYPECACHE_HASH_OPFAMILY 0x0400 #define TYPECACHE_RANGE_INFO 0x0800 #define TYPECACHE_DOMAIN_INFO 0x1000 +#define TYPECACHE_HASH_EXTENDED_PROC 0x2000 +#define TYPECACHE_HASH_EXTENDED_PROC_FINFO 0x4000 /* * Callers wishing to maintain a long-lived reference to a domain's constraint -- cgit v1.2.3