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| author | Alexander Korotkov <akorotkov@postgresql.org> | 2024-08-08 11:48:57 +0300 |
|---|---|---|
| committer | Alexander Korotkov <akorotkov@postgresql.org> | 2024-08-08 11:48:57 +0300 |
| commit | d0c8cf2a56fadb08705433bffb301559d97b0712 (patch) | |
| tree | a2631326bed9e472b342a45b4eb2ad165f9e91b9 /src | |
| parent | 49dc191bd1ae30180597c33e7f75a9950b896ccc (diff) | |
| download | postgresql-d0c8cf2a56fadb08705433bffb301559d97b0712.tar.gz postgresql-d0c8cf2a56fadb08705433bffb301559d97b0712.zip | |
Add a caveat to hash_seq_init_with_hash_value() header comment
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
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/hash/dynahash.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c index 8040416a13c..5d9c62b652a 100644 --- a/src/backend/utils/hash/dynahash.c +++ b/src/backend/utils/hash/dynahash.c @@ -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, |