…- myisam_data_pointer_size is 6 default plus we need space for delete …) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 mysql> show table status like “%bool%” \G *************************** 1…._length: 11 Data_length: 23068672 Max_data_length: 3096224743817215 Index_length: 1024 Data_free: 0 Auto…
Comment: Finding out largest tables on MySQL Server
October 6, 2008 By 27 Comments
… seem to find records getting deleted anywhere. Can you explain why this is? Here is an example. mysql> select count(*) from table… Rows: 14898977 Avg_row_length: 150 Data_length: 2237661184 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time… Rows: 15120698 Avg_row_length: 147 Data_length: 2237661184 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…Cache” which is quite helpful for MySQL Performance optimization tasks but there… value of Qcache_free_blocks relatively to Qcache_free_memory. FLUSH QUERY… calculate by (Com_insert+Com_delete+Com_update+Com_replace)/Qcache_hits…have multiple copies of the same data in cache effectively wasting memory….
Comment: How to calculate a good InnoDB log file size
December 22, 2008 By 38 Comments
mysql> SHOW GLOBAL VARIABLES LIKE ‘innodb_log_file_size’; …deletes all rows and then repopulates it following by a couple of table scans to manipulate the data…STATUS the stats is: Data_length: 165838848 Index_length: 219807744 Data_free: 0 Comment: InnoDB free: 399360 kB Other things…
Post: Percona XtraDB Cluster - installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
…slave on asynchronous replication, galera and built-in mysql replication are independent from each other. Q: I…delete grastate.dat). So, it is appropriate for demo purposes when you would like to show that the full data…it:). Thanks everyone for all these questions, feel free to ask additional ones in…
Post: MySQL Query Cache WhiteSpace and comments
March 20, 2008 By 9 Comments
…bit (see the last query has space after comment deleted) it causes query cache miss. If we look …4 | Sending data | select count(*) from fact where val like “%c%” This tells us we should not use MySQL Command …case So in the nutshell you should be more free now in regards of some SELECT queries not …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost root Sending data…additional pool allocated 16773888 Buffer pool size 262144 Free buffers 0 Database pages 258053 Modified db … Number of rows inserted 143, updated 3000041, deleted 0, read 24865563 0.00 inserts/s, …
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…attempted. btr0cur.h: /* In the pessimistic delete, if the page data size drops below this limit, merging …LIMIT (UNIV_PAGE_SIZE / 2) Q5: When Innodb free space becomes available for use within same object… HT: ha_innodb.cc in 5.1: static MYSQL_SYSVAR_ULONG(thread_concurrency, srv_thread_concurrency, …
Post: Reasons for run-away main Innodb Tablespace
June 10, 2010 By 2 Comments
…these are system tables, also known as data dictionary – table and index definitions and…free space, which you unfortunately can’t reclaim without reloading tour database. This is where Trending can help, for example MySQL… doing such processes in chunks, updating/deleting may be thousands of rows per…
Comment: InnoDB's gap locks
April 13, 2012 By 15 Comments
…with REPEATABLE READ transaction isolation level. mysql> show create table t\G *************************** 1. row …write data, the isolation is READ COMMITED so you can’t update/delete that row, because it doesn’t exist anymore. I hope this example clarify your questions, if not, feel free…
