You wrote
Try to create a btree index on "(bench_hstore->bench_id) WHERE
(bench_hstore->bench_id) IS NOT NULL".
What do you mean exactly?
=> CREATE INDEX myhstore_kps_gin_idx ON myhstore USING gin(kvps) WHERE
??? IS NOT NULL;
My table's def is:
CREATE TABLE myhstore ( id bigint PRIMARY KEY, kvps hstore NOT NULL );
So I'm doing something like:
CREATE INDEX myhstore_kps_gin_idx ON myhstore USING gin(kvps);
Hello ;
I meant a plain old btree index like this :
CREATE INDEX foo ON myhstore((kvps->'yourkeyname')) WHERE
(kvps->'yourkeyname') IS NOT NULL;
The idea is that :
- The reason to use hstore is to have an arbitrary number of keys and use
the keys you want, not have a fixed set of columns like in a table
- Therefore, no hstore key is present in all rows (if it was, you'd make
it a table column, and maybe index it)
- You'll probably only want to index some of the keys/values (avoiding to
index values that contain serialized data or other stuff that never
appears in a WHERE clause)
So, for each key that corresponds to a searchable attribute, I'd use a
conditional index on that key, which only indexes the relevant rows. For
keys that never appear in a WHERE, no index is needed.
gist is good if you want the intersecton of a hstore with another one (for
instance), btree is good if you want simple search or range search.
--
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
