Re: Slow Bitmap Index Scan

On Mon, 2018-12-03 at 18:41 +0000, Scott Rankin wrote:
> Upon further analysis, this is - unsurprisingly - taking place when we have multiple prefixed search terms in a ts_query going against a tsvector index.
>
> We have roughly 30 million rows in the table, and the search column is basically a concatenation of a location's name (think "Walmart #123456") and its street address.
>
> We use these searches mostly for autocompleting of a location search. So the search for that record above might be "Walmart 123", which we change to be to_tsquery('walmart:* &123:*'). We prefix both terms to correct for misspellings or lazy typing.
>
> Is it unrealistic to think that we could have sub-1000ms searches against that size of a table?
>

We've found trigram indexes to be much faster and more useful for these
types of searches than full-text.

https://www.postgresql.org/docs/10/pgtrgm.html

Might be worth a try, if you haven't tested them before.