Hello, Yura. Test results look promising. But it seems like the naming and dynahash API change is a little confusing.
1) I think it is better to split the main part and atomic nentries optimization into separate commits. 2) Also, it would be nice to also fix hash_update_hash_key bug :) 3) Do we really need a SIZEOF_LONG check? I think pg_atomic_uint64 is fine these days. 4) Looks like hash_insert_with_hash_nocheck could potentially break the hash table. Is it better to replace it with hash_search_with_hash_value with HASH_ATTACH action? 5) In such a case hash_delete_skip_freelist with hash_search_with_hash_value with HASH_DETTACH. 6) And then hash_return_to_freelist -> hash_dispose_dettached_entry? Another approach is a new version of hash_update_hash_key with callbacks. Probably it is the most "correct" way to keep a hash table implementation details closed. It should be doable, I think. Thanks, Michail.
