> *Note: * Testing has shown PostgreSQL's hash indexes to perform no
> better than B-tree indexes, and the index size and build time for hash
> indexes is much worse. For these reasons, hash index use is presently
> discouraged.
>
> May I know for simple "=" operation query, for "Hash index" vs.
> "B-tree" index, which can provide better performance please?
If you trust the documentation use a b-tree. If you don't trust the
documentation do your own tests.
please don't cross post.