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From:Paul DuBois Date:January 23 2001 3:56am
Subject:Re: INSERT/UPDATE and MyISAM table
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At 12:00 PM +0900 1/23/01, Nat Sakimura wrote:
>?Hi.
>
>In the MyISAM table without any deleted rows,
>I read in the documentation that INSERT and
>SELECT can occur concurrently.
>
>What about UPDATE? I presume update will
>issue exclusive lock to the table unlike
>insert, but I wanted to know for sure.

In a table with no deleted rows, INSERTS happen by adding the row to
the end of the table.  An UPDATE won't necessarily be able to replace
the row in-place (the new data may be longer than the old), so you won't
be able to perform concurrent SELECTS along with the UPDATE.

>
>Also, after deleting some rows in the table,
>if I do the OPTIMIZE TABLE, does the
>concurrent INSERT/SELECT property return?

Yep.

-- 
Paul DuBois, paul@stripped
Thread
INSERT/UPDATE and MyISAM tableNat Sakimura23 Jan
  • Re: INSERT/UPDATE and MyISAM tablePaul DuBois23 Jan
  • Re: INSERT/UPDATE and MyISAM tableSteve Ruby23 Jan