At 12:00 PM +0900 1/23/01, Nat Sakimura wrote:
>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?
Paul DuBois, paul@stripped