… Sequence Number (LSN) Log Sequence Numbers correspond to given position in the log files and typically incremented for each log record. Innodb uses number… row because it will know transaction 100 was committed when given read operation was started. Note: These are far from all functions…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 4 Comments
…rows from table t2 are read and hash function…Innodb_data_reads 329115 355323 143808 335526 16164 15506 Innodb_pages_read 329115 355323 143808 358308 144798 144881 Innodb_rows…
Post: InnoDB thread concurrency
June 5, 2006 By 4 Comments
… write_row; update_row; delete_row; At start of each of these methods InnoDB checks …_enter_innodb = innodb_concurrency_tickets; ENTER; (full source code: srv_conc_enter_innodb function in innobase/… number of threads inside Innodb might be less than innodb_thread_concurrency especially if number of…
Post: Reasons for run-away main Innodb Tablespace
June 10, 2010 By 2 Comments
…versions of changed rows. The system tables size depends on the number and … be helpful: mysql> select * from innodb_rseg; +———+———-+———-+———+————+———–+ | rseg_id | space_id | zip_size … to higher values though this functionality is a bit experimental. One …
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
…benchmark which concentrates on particular simple storage engine functions and we use it to see …runs. The raw numbers are available here: http://www.mysqlperformanceblog.com/files/benchmarks/innodb-myisam-falcon.html… query performs a scan of all million rows. InnoDB is better than MyISAM by ~30% …
Post: Stored Function to generate Sequences
April 2, 2008 By 17 Comments
…function allows you to “inject” the value to be returned next time this function…Innodb tables to avoid short term “table level locks” which innodb…number of servers or to number… | 102 | 1002 | 103 | 104 | +————+————+————+————+ 1 row in…
Post: Percona Server 5.1.53-12.4
December 29, 2010 By Leave a Comment
…hash functions to provide faster checksums) are now included in distributions. Fixes feature request #689992. (Aleksandr Kuzminsky) Â Other Changes: innodb_…- Warning and error messages for stored routines could incorrectly report row numbers due to a change in the slow_extended patch. (Alexey…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition …
Post: Percona Server 5.5.10 (Release Candidate)
April 4, 2011 By 4 Comments
…Changes Old status variable innodb_row_lock_numbers was renamed to innodb_current_row_locks. (Yasufumi Kinoshita) Old system variable innodb_enable_unsafe_group_commit … version of the original implementation of the Remove Excessive Function Calls feature, which removes some fcntl calls to improve …
Post: Debugging problems with row based replication
May 6, 2010 By 12 Comments
…row-based format does offer advantages particularly if triggers or stored procedures are used, or if non deterministic functions…c1`) ) ENGINE=InnoDB; Query OK, 1 row affected (0.02 sec) Insert a single “seed” row into the…number 15 #100506 12:42:56 server id 1 end_log_pos 340718 Update_rows: …
