On Mon, 2004-08-02 at 14:57, Tinley, Jeremy wrote: > We're upgrading from 3.23.58 to 4.0.20 and found that that although the > ALTER test results of sql-bench had been greatly improved, CREATE has > shown nasty performance degradation. Just before needing to make the > decision to revert back to 3.23.58, we found a post here where someone > had a similar problem when using SAN storage. We see the problem using > hardware RAID, shared storage or local SCSI disks. > > The machine in question is a 3ghz, 4GB RAM, reiserfs. The data and > application reside on local SCSI disks, 10k rpm. All installations are > the MySQL provided linux-binary (x86), Standard releases.
Hi, This is the known issue. In MySQL 4.0.17 calling fsync() on frm files was added during table creation. This was done so create table is more durable if used with transactional tables such as Innodb. It however affects all tables at this point. In most cases new tables are created rarely so it is not the problem, if it is for you case --skip-sync-frm option can be used to avoid such behavior. On other hand B->C changes for some tests surprise me. Are the results stable if you repeat the run ? In some cases especially for short tests deviation can be pretty large. > > Here is an excerpt of sql-bench results: > > Test A B C D E > ------------------------------------------------------ > alter_table_add 60 2 6 8 8 > alter_table_drop 43 1 5 8 8 > create+drop 12 11 11 240 223 > create_MANY_tables 10 11 10 220 228 > create_index 1 1 1 1 1 > create_key+drop 14 15 15 231 221 > create_table 0 0 0 0 0 > select_1_row 0 8 8 8 9 > select_2_rows 1 9 9 9 9 > select_column+column 1 9 9 9 9 > select_group_when_MANY_tables 5 9 11 10 10 > > > Column A is MySQL 3.23.58 > Column B is MySQL 4.0.15 > Column C is MySQL 4.0.16 > Column D is MySQL 4.0.17 > Column E is MySQL 4.0.20 > > > The biggest problem is the create set. That's a HUGE difference in the > exact same hardware. Thoughts? > > > -J -- Peter Zaitsev, Senior Support Engineer MySQL AB, www.mysql.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
