Sorry I forgot you're on mysql 5.1. Maybe it will lock the table. Just run the update deep in the night...
--- Andrea Brancatelli Schema31 S.p.a. Responsabile IT ROMA - BO - FI - PA ITALY Tel: +39. 06.98.358.472 Cell: +39 331.2488468 Fax: +39. 055.71.880.466 Società del Gruppo SC31 ITALIA Il 2016-03-04 09:53 Andrea Brancatelli ha scritto: > Alter doesn't lock the table - but it will slow down the server. > > If you're starting with 650GB table I expect you to come out with, more or > less 200GB after the compression. > > Obviously yes, you need the space for the new table as the process of alter > is creating the new table and then dropping the old one. > > --- > > Andrea Brancatelli > Schema31 S.p.a. > Responsabile IT > > ROMA - BO - FI - PA > ITALY > Tel: +39. 06.98.358.472 > Cell: +39 331.2488468 > Fax: +39. 055.71.880.466 > Società del Gruppo SC31 ITALIA > > Il 2016-03-03 22:08 Simon Buchanan ha scritto: > > On 3 March 2016 at 11:36:59 PM, Andrea Brancatelli (abrancate...@schema31.it) > wrote: > > Yes you can proceed easily with those two settings and have a first bigger > improvement. > > If you're switching away from dbmail I wouldn't go trough the hassle of > upgrading, since the upgrade need to reparse all the message to use the > de-deduplication features. > > Note: the ALTER TABLE will perform the OPTIMIZE TABLE, so you don't need to > run the two commands, just go for the ALTER TABLE. > > Thanks for the reply - my thoughts with the upgrade. The issue with OPTIMISE > TABLE is that it needs the same amount of space to do the optimise, plus the > tables are write locked whist this happens (is this correct?). Thats going to > take a while on a 650GB table :) with live data on it. > > Does Alter table write lock as well? > > PS: also - what do i alter... > > Simon > > _______________________________________________ > DBmail mailing list > DBmail@dbmail.org > http://mailman.fastxs.nl/cgi-bin/mailman/listinfo/dbmail _______________________________________________ DBmail mailing list DBmail@dbmail.org http://mailman.fastxs.nl/cgi-bin/mailman/listinfo/dbmail
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