mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add a caveat to hash_seq_init_with_hash_value() header comment

Browse Source 
The typical use-case for hash_seq_init_with_hash_value() is syscache
callback.  Add a caveat that the default hash function doesn't match syscache
hash function.  So, one needs to define a custom hash function.

Reported-by: Pavel Stehule
Discussion: https://postgr.es/m/CAFj8pRAXmv6eyYx%3DE_BTfyK%3DO_%2ByOF8sXB%3D0bn9eOBt90EgWRA%40mail.gmail.com
Reviewed-by: Pavel Stehule
This commit is contained in:
Alexander Korotkov 2024-08-08 11:48:57 +03:00
parent 49dc191bd1
commit d0c8cf2a56
1 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
src/backend/utils/hash/dynahash.c
View File

@ -1395,6 +1395,11 @@ hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
/*
* Same as above but scan by the given hash value.
* See also hash_seq_search().
*
* NOTE: the default hash function doesn't match syscache hash function.
* Thus, if you're going to use this function in syscache callback, make sure
* you're using custom hash function. See relatt_cache_syshash()
* for example.
*/
void
hash_seq_init_with_hash_value(HASH_SEQ_STATUS *status, HTAB *hashp,