… groups with some metadata: BEGIN; INSERT INTO users_groups (user_id, group_id) VALUES (100, 1); UPDATE groups SET last_joined=NOW… both of the above examples you can imagine plenty of concurrent clients attempting to modify the same record at once. But… parent group row so often? INSERT INTO users_groups (user_id, group_id, joined) VALUES (100, 1, NOW()); Conclusion Choosing a system…
Comment: SimCity outages, traffic control and Thread Pool for MySQL
March 21, 2013 By 16 Comments
…just simple queries or simple transactions but high concurrency with complex transactions as well — items like the…03/01/building-a-mysql-private-cloud-step-1/ — this will be a series of posts over…to host rapidly scalable NDB clusters (commence with inserting a shameless plug that users can then …
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…
Post: MyISAM concurrent insert
June 13, 2006 By 12 Comments
… better) threads Quadxeon with enabled concurrent-insert Quadxeon –skip-concurrent-insert Sun V40z with enabled concurrent-insert Sun V40z –skip-concurrent-insert 1 44.08 64.82 61.06… you are using range-queries and doing INSERT not often than disabling concurrent-insert with –skip-concurrent-insert can improve MyISAM performance. As I said…
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 5 Comments
… number of threads that can enter InnoDB concurrently is determined by the innodb_thread_concurrency variable. A thread is placed in a… of rows inserted – 1 INSERT w/FOREIGN KEY constraint: Number of rows inserted – 1 SELECT: 1 ticket per row returned UPDATE: 1 ticket per row examined + 1 ticket…
Comment: Using MyISAM in production
June 17, 2006 By 36 Comments
…’ve been puzzling over concurrent inserts for a while while using v5.0.15 and we’ve discovered that concurrent inserts don’t seem to be allowed with a spatial key defined on our spatial column. (waiting for write ‘concurrent insert lock…) Removing just the spatial key frees up concurrent inserts to work as they should by default (concurrent_insert=1) Although I may have missed something…
Post: Announcing Percona Server 5.1.65-14.0
September 4, 2012 By Leave a Comment
… the log tracking thread. HandlerSocket has been upgraded to version 1.1.0. Bugs Fixed: Loading LRU dump was preventing shutdown. Bug… fixed #999147 (Laurynas Biveinis). Fixed the upstream MySQL bug #66301. Concurrent INSERT … ON DUPLICATE KEY UPDATE statements on a table with an… some rows being updated rather than inserted) with the default value of innodb_autoinc_lock_mode=1. Bug fixed #1035225 (Alexey Kopytov…
Post: Avoiding auto-increment holes on InnoDB with INSERT IGNORE
November 29, 2011 By 8 Comments
… concurrency and performance. The problems are even worse with long running queries like INSERT INTO table1 … SELECT … FROM table2. In version 5.1…-INC. We have recovered the concurrency and the performance but with a small cost. Queries like INSERT … ON DUPLICATE KEY UPDATE produce… and concurrency. How can I solve this problem for INSERT IGNORE? As I informed you before, it is not documented that INSERT IGNORE…
Post: INSERT INTO ... SELECT Performance with Innodb tables.
July 12, 2006 By 22 Comments
… pretty bad for MySQL Performance and concurrency ? The reason is – replication. In MySQL before 5.1 replication is statement based which means…/tbl1.txt’ INTO TABLE tbl2; instead of: INSERT INTO tbl2 SELECT * from tbl1; INSERT … INTO OUTFILE does not have to set extra… use 1, locked 1 2539 lock struct(s), heap size 224576 MySQL thread id 1794751, query id 6994931 localhost root Sending data insert…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… note the “Auto Increment Issue” is finally solved in 5.1 which may be even better. Q28: My impression (from an… been several MySQL bugs opened about multi-core scalability (concurrent queries, autoincrement, concurrent inserts, instrumentation, etc.). Rather than treat each defect as an…
