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| author | Robert Haas <rhaas@postgresql.org> | 2017-08-31 22:21:21 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2017-08-31 22:21:21 -0400 |
| commit | 81c5e46c490e2426db243eada186995da5bb0ba7 (patch) | |
| tree | a6cb745131c45a06fa43746a17a69e1dc9daa44a /src/backend/commands/opclasscmds.c | |
| parent | 2d44c58c79aeef2d376be0141057afbb9ec6b5bc (diff) | |
| download | postgresql-81c5e46c490e2426db243eada186995da5bb0ba7.tar.gz postgresql-81c5e46c490e2426db243eada186995da5bb0ba7.zip | |
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
Diffstat (limited to 'src/backend/commands/opclasscmds.c')
| -rw-r--r-- | src/backend/commands/opclasscmds.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/src/backend/commands/opclasscmds.c b/src/backend/commands/opclasscmds.c index a31b1acb9c6..d23e6d6f250 100644 --- a/src/backend/commands/opclasscmds.c +++ b/src/backend/commands/opclasscmds.c @@ -18,6 +18,7 @@ #include <limits.h> #include "access/genam.h" +#include "access/hash.h" #include "access/heapam.h" #include "access/nbtree.h" #include "access/htup_details.h" @@ -1129,7 +1130,8 @@ assignProcTypes(OpFamilyMember *member, Oid amoid, Oid typeoid) /* * btree comparison procs must be 2-arg procs returning int4, while btree * sortsupport procs must take internal and return void. hash support - * procs must be 1-arg procs returning int4. Otherwise we don't know. + * proc 1 must be a 1-arg proc returning int4, while proc 2 must be a + * 2-arg proc returning int8. Otherwise we don't know. */ if (amoid == BTREE_AM_OID) { @@ -1172,14 +1174,28 @@ assignProcTypes(OpFamilyMember *member, Oid amoid, Oid typeoid) } else if (amoid == HASH_AM_OID) { - if (procform->pronargs != 1) - ereport(ERROR, - (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), - errmsg("hash procedures must have one argument"))); - if (procform->prorettype != INT4OID) - ereport(ERROR, - (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), - errmsg("hash procedures must return integer"))); + if (member->number == HASHSTANDARD_PROC) + { + if (procform->pronargs != 1) + ereport(ERROR, + (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), + errmsg("hash procedure 1 must have one argument"))); + if (procform->prorettype != INT4OID) + ereport(ERROR, + (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), + errmsg("hash procedure 1 must return integer"))); + } + else if (member->number == HASHEXTENDED_PROC) + { + if (procform->pronargs != 2) + ereport(ERROR, + (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), + errmsg("hash procedure 2 must have two arguments"))); + if (procform->prorettype != INT8OID) + ereport(ERROR, + (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), + errmsg("hash procedure 2 must return bigint"))); + } /* * If lefttype/righttype isn't specified, use the proc's input type |