Always take care what you want to achieve! And consider the circumstances. Yes, adding a lot of indexes makes queries faster. But makes inserts/deletes/updates slower.
Alex's problem is NOT that his/her queries takes too long, the problem is that optimize takes too long. Which is something completely different. Cheers /rudy -----Original Message----- From: Veysel Harun Sahin [mailto:[EMAIL PROTECTED] Sent: dinsdag 15 juli 2003 15:22 To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: Re: Managing big tables http://www.mysql.com/doc/en/Data_size.html [EMAIL PROTECTED] wrote: > Hello, > i've got a little problem, > we're using mysql with two big tables (one has 90 Mio. Rows (60 Gb on > HD), the other contains nearly 200.000.000 (130 Gb on HD). > Now we want to delete some rows from these tables to free diskspace. > It seems that MySQL frees the harddisk-space which > was used by these rows only after optimization, which lasts very long > on these tables. Both tables are "dynamic" in terms of row-format > what seems to extend the time needed for optimization. I tried to > convert the smaller one to "fixed"-row-format, which increased the > disk-space of its data-file from 30 Gb to 60 Gb. This would not be the > problem, but some SQLs which are run daily > on this table now run 4 times slower than with dynamic structure. > > So, my questions are: > 1) Did i something wrong while converting to fixed row-format ? (i > found no indication) > 2) Is the fixed structure really faster on optimization ? > 3) Can anybody confirm the slow-down on big tables when converted from > dynamic to fixed ? > (on small tables fixed were faster) > > I'm running SuSE Linux, Kernel 2.4.20, the above behaviour could be > reproduced with our productive server (MySQL 3.23) and > with a test server (MySQL 4.0.12). > > thanks in advance, > alex > > > -- Veysel Harun Sahin [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
