Re: Using index for substring search

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Re: Using index for substring search

От:
Bruce Momjian <pgman@candle.pha.pa.us>
Дата:
Lec wrote:
> Is it possible for postgreSQL 7.2 to use index search for the following
> queries:
> 
> select name from item where substring(itemcode,1,3) = '101';
> select name from item where itemcode like '101%';
> 
> if I have an index on itemcode.
> 
> Version 6.5.3 can use index search for the first query.

Are you sure?  7.2 and I thought earlier releases could only use an
index on the second query.  There is even an FAQ item.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Using index for substring search

От:
Lec <englim@pc.jaring.my>
Дата:
Is it possible for postgreSQL 7.2 to use index search for the following
queries:

select name from item where substring(itemcode,1,3) = '101';
select name from item where itemcode like '101%';

if I have an index on itemcode.

Version 6.5.3 can use index search for the first query.

Thanks,
Thomas.
FAQ