…but also updates groups with some metadata: BEGIN; INSERT INTO users_groups (user_id, group_id) VALUES… above examples you can imagine plenty of concurrent clients attempting to modify the same record at … really bad in standalone Innodb, you might consider relaxing the fsync: set innodb_flush_log_at…
Comment: Benchmarking Percona Server TokuDB vs InnoDB
May 8, 2013 By 32 Comments
1) What concurrency did you use for the INSERT test? Don’t know if TokuDB handle concurrent workload as well as InnoDB 2) Can… a secondary index? I heard that TokuDB is slower than InnoDB on SELECT but it’d be interesting to see by…
Post: Concurrent inserts on MyISAM and the binary log
May 14, 2008 By 7 Comments
… and concurrent inserts into tbl2 are running fine. If you now run the following query, INSERT INTO tbl1 SELECT * FROM tbl2 The concurrent inserts into… But on INSERT…SELECT, you’ll see this: Read lock without concurrent inserts That read lock is what’s blocking the concurrent inserts from happening… INTO OUTFILE followed by LOAD DATA INFILE. You can use InnoDB instead. Or you can do something more elaborate and application…
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 5 Comments
… to most users? INSERT w/PRIMARY KEY defined: Number of rows inserted – 1 INSERT w/FOREIGN KEY constraint: Number of rows inserted – 1 SELECT…_size=1900M innodb_thread_concurrency=16 innodb_flush_method = O_DIRECT innodb_write_io_threads=8 innodb_read_io_threads=8 innodb_io_capacity=500 innodb_max…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… workload has a hi amount of concurrent writes to about 6 tables, what version of Innodb/MySQL would you recommend? I’ve… – choosing innodb_buffer_pool_size Q36: There have been several MySQL bugs opened about multi-core scalability (concurrent queries, autoincrement, concurrent inserts, instrumentation, etc…
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
… me start with most popular transactional storage engine for MySQL – Innodb. Innodb Storage Engine was covered in a lot of talks, many…. Fast Index creation will allow Innodb to build indexes by sorting rather by row by row insertions as it currently does which… statement duration for Inserts with auto-increment column. This starts giving you problems if you have a lot of concurrent inserts happening to…
Post: Fix of InnoDB/XtraDB scalability of rollback segment
January 18, 2009 By 9 Comments
… sysbench write workload (benchmark emulates intensive insert/delete queries). By our results the problem is in concurrency on rollback segment, which by…_trx_commit=2 innodb_log_buffer_size=8M innodb_log_files_in_group=2 innodb_log_file_size=128M innodb_thread_concurrency=0 innodb_extra_rsegments…
Post: InnoDB auto-inc scalability fixed
September 26, 2007 By 18 Comments
… is obtained, instead of usual row-level locks. With many concurrent inserted threads this causes serious scalability problems, and in our consulting… is the fix introduces new system variable innodb_autoinc_lock_mode which determines behavior of InnoDB for tables with autoinc. I do…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…innodb_change_bufferingblogpercona.commanual innodb_checksumsblogpercona.commanual innodb_commit_concurrencyblogpercona.commanual innodb_concurrency_ticketsblogpercona.commanual innodb_data_file_pathblogpercona.commanual Innodb_data_fsyncsblogpercona.commanual innodb…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… inside Innodb kernel and still has 400 tickets to use. Innodb tries to limit thread concurrency allowing only innodb_thread_concurrency threads to run inside Innodb… if there are any records is insert buffer. Next it shows how many inserts were done in insert buffer, how many recs were…
