On Wed, Mar 16, 2016 at 6:53 AM, Andreas Joseph Krogh <andr...@visena.com> wrote:
> På onsdag 16. mars 2016 kl. 14:37:27, skrev Tom Lane <t...@sss.pgh.pa.us>: > > Andreas Joseph Krogh <andr...@visena.com> writes: > > 1. Why isnt' folder_id part of the index-cond? > > Because a GIN index is useless for sorting. > > > 2. Is there a way to make it use the (same) index to sort by > > received_timestamp? > > No. > > > 3. Using a GIN-index, is there a way to use the index at all for sorting? > > No. > > > 4. It doesn't seem like ts_rank uses the index for sorting either. > > Same reason. > > regards, tom lane > > > So it's basically impossible to use FTS/GIN with sorting on large datasets? > Are there any plans to improve this situation? > I don't see why it would not be possible to create a new execution node type that does an index scan to obtain order (or just to satisfy an equality or range expression), and takes a bitmap (as produced by the FTS/GIN) to apply as a filter. But, I don't know of anyone planning on doing that. Cheers, Jeff
