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From:Jan Dvorak Date:March 21 2000 8:21am
Subject:Re: LIKE '%xxx%' much faster on BLOBs than on TEXTs (Win only)
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Thimble Smith wrote:
> 
> On Fri, Mar 17, 2000 at 04:21:27PM +0100, Florian Kusche wrote:
> >Hello Jan,
> >
> >> A potential explanation is that the table with the TEXT field
> >> on your NT system is severely fragmented.  This can occurr
> >> e.g. if you add records by an insert, and then you update
> >> the contents of the TEXT field.  Or if you had some deletes.
> >
> >I don't think so. I did the following:
> >- CREATE TABLE
> >- INSERT all data
> >- do the select
> >
> >If I have TEXT-columns, it's slow and with BLOB columns it's fast.

O.k., then my explanation does not apply to your case.

> I think the problem is that with TEXT columns the comparisons are
> case insensitive, but with BLOB columns the comparisons can be
> done byte by byte.

Does the Win32 version use some library
calls to compare strings/characters?

Jan
Thread
LIKE '%xxx%' much faster on BLOBs than on TEXTs (Win only)Florian Kusche17 Mar
  • Re: LIKE '%xxx%' much faster on BLOBs than on TEXTs (Win only)Jan Dvorak17 Mar
  • Re: LIKE '%xxx%' much faster on BLOBs than on TEXTs (Win only)Florian Kusche17 Mar
    • Re: LIKE '%xxx%' much faster on BLOBs than on TEXTs (Win only)Thimble Smith17 Mar
  • Re: LIKE '%xxx%' much faster on BLOBs than on TEXTs (Win only)Jan Dvorak21 Mar