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From:Michael Widenius Date:June 28 2009 2:56pm
Subject:re: feedback/review requested for fix to MySQL bug #45754
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>>>>> "Zardosht" == Zardosht Kasheff <zardosht@stripped> writes:

Zardosht> Hello,
Zardosht> I am interested to hear feedback on a patch I have submitted for a
Zardosht> feature request, bug #45754 (

Zardosht> The patch increases the maximum number of columns in a MySQL key from 16 to
> 32.

Looks ok and should be relatively safe to do.

Here is what I wrote about the patch in the bug report:


One problem with the patch is that it will unconditionally increase
the space needed for the keys in the .frm file and for people with a
lot of fields where the total length of the .frm is close to 64K after
the change they may not be able to ALTER the table again.

The way to fix the above would be to add the number of used key
segments to create_frm().

It should also be safe to increase the number of segments in MyISAM to 32 too.
(One will get a warning in debug log for old files, but this shouldn't
be critical)


feedback/review requested for fix to MySQL bug #45754Zardosht Kasheff25 Jun
  • re: feedback/review requested for fix to MySQL bug #45754Michael Widenius28 Jun