Re[2]: [GENERAL] Generic search - Mailing list pgsql-general

From Sferacarta Software
Subject Re[2]: [GENERAL] Generic search
Date
Msg-id 17687.981204@bo.nettuno.it
Whole thread Raw
In response to Re: [GENERAL] Generic search  (Taral <taral@cyberjunkie.com>)
List pgsql-general
Hello Taral,

venerdì, 4 dicembre 98, you wrote:

>>hygea=> explain select * from comuni where nome = 'A%';
>>NOTICE:  QUERY PLAN:
>>Index Scan using nome_comune_idx on comuni  (cost=2.05 size=2 width=84)
>>^^^^^

T> The question was about LIKE, not =. Because LIKE uses regexp-style matching and
T> we have no substring index functionality, it cannot use the index. If you're
T> always matching on the first character, you can do something like fulltextindex
T> does and use triggers and a second (indexed) table to be able to match on the
T> first character only.

Sorry, my fault.

hygea=> explain select * from comuni where nome like 'A%';
NOTICE:  QUERY PLAN:
Index Scan using nome_comune_idx on comuni  (cost=72.34 size=1 width=84)
EXPLAIN

-Jose'-



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