…mysql and an /etc/my.cnf, and the server is installed in /customsoftware/mysql with a different…mysql.* tables…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… on that. Mind however that different file systems (and different versions of them) might be using different units for these options so you… Model: LSI MegaRAID 8704EM2 (scsi) Disk /dev/sda: 2339840000s Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…_join: No Tmp_table: No Tmp_table_on_disk: No # Filesort: No Filesort_on_disk: No Merge_passes: 0… captured which are actually invocations of 167 different queries. Following that there are summaries of… about the underlying tables involved and the query execution plan used by MySQL. The end result…
Post: TMP_TABLE_SIZE and MAX_HEAP_TABLE_SIZE
January 19, 2007 By 17 Comments
…two types of tables differ in that MEMORY tables are not subject to storage conversion, whereas internal tables are: * If an internal table becomes too…ted.mysql.internal +6 -0 BUG #4291 fix: new configuration option “disk-tmp-table-size” introduced to set maximum expected on-disk temporary table …
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… tables would be repaired at the same time. What if user uses all 100 of his allowed connections to ALTER 100 different tables… your MySQL server to run out of file descriptors. The same is true for Partitioned tables in MySQL 5.1 Disk Space For MyISAM tables hosting providers used to use disk quotas for MyISAM tables. You can also…
Post: ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
… TABLE performance with fast index creation and without it with different buffer pool sizes. Results are pretty interesting. I used modified Sysbench table for these tests because original table as initially…*SATA disks in RAID10. I used 10mil row table which would look as following in terms of data and index size: mysql> show table…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
…: 1113 LOGGING OF THE REPLICATED STATEMENTS Normally MySQL will not write into slow log any…table will be set. Sometimes that table must be created on disk instead of in memory, in such case Disk_tmp_table… acutal number of read operations may be different, but since this can be done asynchronously,…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
…Innodb with MySQL we can use Innodb_data_reads , Innodb_data_writes, Innodb_os_log_fsyncs for your disk …to use this information is to compare systems with different memory amount having same workload. You will often … scan 0% yes, 99% no # Tmp table 1% yes, 98% no # Tmp table on 1% yes, 98% no In …
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
…TABLE, but do they make enough difference…table: sysbench –test=oltp –oltp-table-size=20000000 –mysql-table-engine=innodb –mysql-socket=/tmp/mysql_sandbox5524.sock –mysql-db=test –oltp-table…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
…mysql-replication-delay plugin checks for excessive delay, and pmp-check-mysql-replication-running checks that replication is functioning correctly. Replicas have different…table-checksum tool from Percona Toolkit can generate table checksums, and the pmp-check-pt-table…
