William Temperley wrote:
My problem is I have several text fields in the address data, for which postgres ignores the indexes (btree).
"Index Scan using ap_idx_pc on ap (cost= 0.00..15.30 rows=1 width=188)" " Index Cond: (((pc_)::text >= 'OX2 0'::character varying) AND ((pc_)::text < 'OX2 1'::character varying))" " Filter: ((pc_)::text ~~ 'OX2 0%'::text)" And the NEW:- "Seq Scan on ap (cost=0.00..4652339.33 rows=1 width=189)" " Filter: ((pc_)::text ~~ 'OX2 0%'::text)"
It's almost certainly a locale thing. Your old locale was "C" and the new one is "en_GB.UTF-8" or similar. This means that simple sorting has been replaced by something more library-like.
You can either dump the database, re-run initdb with the "C" locale and restore, or read up on text_pattern_ops/varchar_pattern_ops in the manual (11.8. Operator Classes). Basically it tags an index as working with pattern-matching in the current locale.
the strange thing is my btree indexes on the uk roads data work fine.
Do they use like, or explicit range-checks? -- Richard Huxton Archonet Ltd ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly