Updated RUM-index and support for bigint as part of index - Mailing list pgsql-general
Hi.
I see the RUM-index is updated, which is great!
I wonder, to be able to sort by timestamp one has to create the index like this:
CREATE INDEX rumidx ON origo_email_delivery USING rum (fts_all rum_tsvector_timestamp_ops, received_timestamp) WITH (attach = 'received_timestamp', TO = 'fts_all', order_by_attach = TRUE );
Then, to be able to use the index for sorting by the "received_timestamp"-column one has to issue a query like this:
EXPLAIN ANALYZE SELECT
del.entity_id, del.subject, del.received_timestamp, fts_all <=> to_tsquery('simple', 'andreas&kr') AS rank FROM origo_email_delivery del WHERE del.fts_all @@ to_tsquery('simple', 'andreas&kr') ORDER BY '2000-01-01' :: TIMESTAMP <=> del.received_timestamp LIMIT 10;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=14.40..26.47 rows=10 width=89) (actual time=10.908..10.952 rows=10 loops=1) -> Index Scan using rumidx on origo_email_delivery del (cost=14.40..3221.22 rows=2657 width=89) (actual time=10.906..10.947 rows=10 loops=1) Index Cond: (fts_all @@ '''andreas'' & ''kr'''::tsquery) Order By: (received_timestamp <=> '2000-01-01 00:00:00'::timestamp without time zone) Planning time: 0.491 ms Execution time: 11.010 ms
(6 rows)
The ORDER BY part seems strange; It seems one has to find a value "lower than any other value" to use as a kind of base, why is this necessary? It also seems that in order to be able to sort DESC one has to provide a timestamp value "higher than any other value", is this correct?
It would be great if the docs explained this.
I really miss the opportunity to include a BIGINT as part of the index, so that the WHERE-clause could be like this:
WHERE del.fts_all @@ to_tsquery('simple', 'andreas&kr') AND del.folder_id IN (1,2,3)
Having this would be perfect for my use-case searching in email in folders, sorted by received_date, and having it use ONE index.
Will this be supported?
Thanks.
-- 
Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
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