Thread: <-> Operator on Trigram Index

<-> Operator on Trigram Index

From

Jeffrey Kamei

Date:

14 November 2018, 01:42:51

I'm trying to get the <-> operator to recognize a trigram index (GIST) I've set on a table. Using `EXPLAIN VERBOSE` I can see the query engine ignoring the trigram index when using the `<->` operator. However if I use the `%` operator, the index is found and used. Can you explain why this is happening? As far as I can tell from the documentation, the `<->` operator should be using the index as well.

Re: <-> Operator on Trigram Index

From

Arthur Zakirov

Date:

15 November 2018, 12:28:16

Hello,

On 14.11.2018 01:42, Jeffrey Kamei wrote:
> I'm trying to get the <-> operator to recognize a trigram index (GIST) 
> I've set on a table. Using `EXPLAIN VERBOSE` I can see the query engine 
> ignoring the trigram index when using the `<->` operator. However if I 
> use the `%` operator, the index is found and used. Can you explain why 
> this is happening? As far as I can tell from the documentation, the 
> `<->` operator should be using the index as well.

Yes <-> operator should use a GiST index. Can you show your query and 
its plan?

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