Re: Gist indexes on int arrays

Oleg Bartunov <oleg(at)sai(dot)msu(dot)su> writes:

> > db=# CREATE INDEX cache_gist_idx on cache using gist ( foo_id , attribute_set gist__int_ops);

> what's the time to create gist indices separately ? I suppose 15m is the time
> to create btree index on *single* column ?

Unfortunately I can't run timing tests on it without invalidating whatever
timing results I get for the current index build which is still running.

postgres 30176 93.7 21.7 68964 56096 ? R 11:08 133:39 postgres: postgres slo [local] CREATE INDEX

15m was what i remember as the time to build a unique (non-gist) btree index
on (foo_id,bar_id) where foo_id is the same integer column as the leading
column in the gist index, and bar_id is another integer column.

There are 1,161,435 records, with 384 distinct values of foo_id. The number of
records per value of foo_id ranges from 1 to 11,474.

The annoying thing here is that 99% of the attribute_set columns will have
exactly one value in them. All this work is for the 1% that can have multiple
values.

--
greg