On Wed, Jun 20, 2012 at 1:39 PM, Alan Hodgson <ahodgson@xxxxxxxxx> wrote:
On Wednesday, June 20, 2012 01:10:03 PM Sam Z J wrote:Indexing helps not at all. If the search string starts with a wildcard you
> Hi all
>
> I'm curious how is wildcards at both ends implemented, e.g. LIKE '%str%'
> How efficient is it if that's the only search criteria against a large
> table? how much does indexing the column help and roughly how much more
> space is needed for the index?
>
will always get a sequential scan of the whole table.
Look at the full text search documentation for a better approach.
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Zhongshi (Sam) Jiang
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