… but it seems to be down. Basically I have a problem regarding long running select query. A query runs for say…’ queries which perform small insert or updates into completely different table (unrelated to the select query) also get hang up. If… as ‘null’ and Info says ‘commit’ The ‘Table_locks_waited’ remains zero while the ‘Table_locks_immediate’ keeps increasing I have disabled the query…
Post: Choosing a MySQL HA Solution - Post-Webinar Q&A
June 7, 2013 By Leave a Comment
…a specific database, a set of databases, or specific tables; you can also configure the slave to replicate …want to keep an eye on to prevent a problem before it occurs. For example, if you see a…on top of a clustered filesystem with an external lock manager. You might say that MySQL/NDB Cluster …
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…where the client is forced to correct the problem before it can commit. It is NOT the…These are maintained in separate tables and there also exists a users_groups table to define the relationship between …the 1 RTT). The other transactions will lock wait until the lock(s) they need are available. …
Comment: Implications of Metadata Locking Changes in MySQL 5.5
March 27, 2013 By 9 Comments
… hold any row lock. The point was to show the implications of a transaction not holding metadata locks on tables that have been queried in the transaction, which causes problems by breaking isolation. However, in your case what you are doing is that by executing an update query on the table…
Post: MySQL 5.6 Compatible Percona Toolkit 2.2 Released
March 25, 2013 By 2 Comments
…. There’s still one noticeable omission: pt-table-sync. It’s still unclear if or … configurable. Also, we removed –lock-wait-timeout which set innodb_lock_wait_timeout because that now conflicts… Galera Cluster), upgrades are fashionable, so to speak. Problem is: “original” pt-upgrade was too noisy …
Post: Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
… completed regardless of its state before updating. This caused some problems for some users, especially if automatic upgrading was configured on… bug #63144. CREATE TABLE or CREATE TABLE IF NOT EXISTS statements on an existing table could wait on a metadata lock instead of failing or returning immediately if there is a transaction that executed a query which opened that table. Bug…
Post: Percona Server for MySQL 5.5.30-30.2 now available
April 10, 2013 By 10 Comments
… bug #63144. CREATE TABLE or CREATE TABLE IF NOT EXISTS statements on an existing table could wait on a metadata lock instead of failing or returning immediately if there is a transaction that executed a query which opened that table. Bug…_list scan in read_view_open_now() which is another problem originally reported as upstream bug #49169. This also provides much…
Post: Webinar: MySQL 5.6 Performance Schema
May 13, 2013 By 5 Comments
… Problems with excessive temporary tables and external sorts Excessive internal mutex contention Slow queries due to waits on InnoDB locks and Meta Data locks…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… for any SELECT statement to complete in order to complete locking tables. This means if you have workload which includes some very… field list from all tables) Reads though would not be blocked, ie there is no MYISAM like table lock priority problem with pending WRITE query blocks any READ queries to execute on the table. mysql> show processlist…
Post: How much memory Innodb locks really take ?
July 13, 2006 By 11 Comments
… bit of background – in Innodb row level locks are implemented by having special lock table, located in the buffer pool where small record allocated for each hash and for each row locked on that… consumption by row level locks should not be the problem even for rather large databases – even billion of locked rows should take half…
