Re: BUG #15491: index on function not being used for full text search when querying through a view

Hello,

On 07.11.2018 11:30, PG Bug reporting form wrote:
> I'm trying to implement full text search with PostgreSQL,
> I found when using a function create index in conjunction with querying
> through a view, will cause postgres not to use the index.
> Below are example for each scenario.
>
> When only using expression index, the index is used
> https://dbfiddle.uk/?rdbms=postgres_11&fiddle=16ed7a04389ebf71dc5a1fb2daa34058
>
> When only using view, the index is also used
> https://dbfiddle.uk/?rdbms=postgres_11&fiddle=e8d50181b8612421773c2da39e45c9fd
>
> view + expression, the index is NOT used
> https://dbfiddle.uk/?rdbms=postgres_11&fiddle=19d7b923514f100f6e402b54624cc972
>
> I've avoid using function in my app, but I think this should have worked.
> Thank you

I'm not strong in various function volatility categories. But it seems
that STABLE function solves this. See:

https://dbfiddle.uk/?rdbms=postgres_11&fiddle=eadfe2af10113ca53ff9698228728490

--
Arthur Zakirov
Postgres Professional: http://www.postgrespro.com
Russian Postgres Company