… 755 sec 4 lock struct(s), heap size 1248, 3 row lock(s), undo log entries 1 MySQL thread id 3, OS thread… prevent problems with the replication you should change the binary log format to “row”. Depending on the statement, the behavior of… your application can deal with phantom reads and your binary log is in row format, changing the ISOLATION to READ COMMITTED…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… use 1, locked 1 3 lock struct(s), heap size 368, undo log entries 1 MySQL thread id 9697561, query id 188161264 localhost…_max_purge_lag will become your friend. “undo n:o” will show the undo log record number which purge is currently processing, if… log files. By monitoring log sequence number and value up to which logs have been flushed you can check if your innodb_log_buffer_size…
Post: Estimating Undo Space needed for LVM Snapshot
June 9, 2008 By 5 Comments
… adjusted. If you have 10GB database size (including logs etc) you will not need 18GB undo snapshot no matter how heavy IO is… you get 10GB worth of logs during the time of backup you will need 10GB of undo space. Second, limit batch activities… (and so you may be able to allow full database size for undo space without thinking). If such hard drive dies you…
Post: Choosing proper innodb_log_file_size
July 3, 2006 By 12 Comments
… and why large innodb_log_file_size slows down recovery. During startup after crash Innodb scans log files to find log records which only…” phase “undo” phase can’t be reduced by sizing your log files. Even more undo phase can be slower with small log files. Undo phase takes… way you can reduce “undo” phase is size your transactions appropriately – so updates/inserts/deletes can be sized to affect limited number of…
Post: ACTIVE with Locks – Now thats a problem !
June 2, 2011 By 2 Comments
… thread id 1224980800 3 lock struct(s), heap size 368, 1 row lock(s), undo log entries 1 MySQL thread id 1720, query… id 1229596992 3 lock struct(s), heap size 368, 1 row lock(s), undo log entries 2 In this case we see transactions are holding some locks and perform some update/deletes as there are undo log…
Post: How InnoDB handles REDO logging
February 3, 2011 By 18 Comments
…. Percona Server with XtraDB allows you to control the transaction log record size, as better performance may be gained with 4096 byte… be logged and then later rolled back do to an error or a specific request, as part of the DO-UNDO-REDO protocol InnoDB also records UNDO information, however that is stored outside of the transaction log and as such…
Comment: How to load large files safely into InnoDB with LOAD DATA INFILE
September 30, 2009 By 28 Comments
… sure I understand your two points above, namely: >> lots of undo log entries collect in the tablespace… from here (http://dev.mysql…/5.1/en/multiple-tablespaces.html) i see that the undo log entries are kept in the shared tablespace (i’m not… be approximately this size just because i’m doing this as a transaction. once the transaction commits, the undo logs will be ‘discarded…
Post: Connecting orphaned .ibd files
May 13, 2011 By 12 Comments
… of InnoDB pages. A page is 16k long (UNIV_PAGE_SIZE in the source code). Let’s take a look at the page header: InnoDB Page Header Name Size Description FIL_PAGE_SPACE_OR_CHKSUM 4 /* in < MySQL-4... log serial number of page’s latest log record FIL_PAGE_TYPE 2 current defined types are: FIL_PAGE_INDEX, FIL_PAGE_UNDO_LOG…
Post: INSERT INTO ... SELECT Performance with Innodb tables.
July 12, 2006 By 21 Comments
…_locks_unsafe_for_binlog option with caution. Note disabling binary logs is not enough to trigger relaxed locks. You have to…, locked 1 LOCK WAIT 3 lock struct(s), heap size 320, undo log entries 1 MySQL thread id 1794760, query id 6994946 localhost… in use 1, locked 1 2539 lock struct(s), heap size 224576 MySQL thread id 1794751, query id 6994931 localhost root…
Comment: Undo area size restriction needed for Innodb
November 14, 2006 By 4 Comments
innotop (http://www.xaprb.com/innotop/) shows undo size in the InnoDB Transaction mode. Press capital T to enter … way to see how long they are and how many undo log entries they generate.
