… no need to create locks to prevent that from happening. 2- innodb_locks_unsafe_for_binlog = 1. Disables the gap locks except for foreign….1/en/innodb-locks-set.html. Conclusion MySQL uses REPEATABLE READ as the default isolation level so it needs to lock the index records and the gaps to avoid phantom reads and…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…read_ahead_thresholdblogpercona.commanual innodb_read_io_threadsblogpercona.commanual innodb_replication_delayblogpercona.commanual innodb_rollback_on_timeoutblogpercona.commanual Innodb_row_lock…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…, with another person reading all the notes …mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –skip-external-locking –port=3306 –socket=/var/db/mysql/mysql…Created_tmp_tables and Created_disk_tmp_tables, I’ll paste in mysql…these factors (schema, queries, indexing) in isolation, because they…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… thread id 3771312 starting index read mysql tables in use 1, locked 1 LOCK WAIT 3 lock struct(s), heap size 320 MySQL thread id 30898, query… 4078512 starting index read, thread declared inside InnoDB 500 mysql tables in use 1, locked 1 3 lock struct(s), heap size 320 MySQL thread id… list 0, single page 0 Pages read 57973114, created 251137, written 10761167 9.79 reads/s, 0.31 creates/s, 6.00 writes/s…
Post: Paul McCullagh answers your questions about PBXT
November 20, 2009 By 2 Comments
…locking. Read locks are not required because each transaction effectively gets its own snapshot of the database. And write locks…locks when calling back into MySQL to do things like open a table, create a session structure (THD) or create…
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…_create_db’, ’0′ ‘Com_create_function’, ’0′ ‘Com_create_index‘, ’0′ ‘Com_create…read_first’, ’1100773′ ‘Handler_read_key’, ’2491307870′ ‘Handler_read_next’, ’1266206297′ ‘Handler_read_prev’, ’0′ ‘Handler_read_rnd’, ’234159075′ ‘Handler_read…mysql innodb_log_arch_dir=/var/log/mysql innodb_table_locks…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
… tables. So first MySQL versions did not …delay_key_write Delay updating indexes for MyISAM tables. …lock_count Variable which may save you from read starvation if there are constant writes to the table. Works with table locks…size implicit temporary table (created during query execution automatically…
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May 11, 2011 By 2 Comments
… Max_data_length: 0 Index_length: 539279360 Data_free: 4194304 Auto_increment: NULL Create_time: 2011-05-…-sample-pages=256 innodb-stats-update-need-lock=0 innodb-status-file innodb-strict-mode …256K tmp-table-size=64M transaction-isolation=READ-COMMITTED user=mysql wait-timeout=86400 To be continued …
Post: Tuning for heavy writing workloads
October 14, 2009 By 9 Comments
… “xx-lock on RW-latch at 0x7f2ff40a3dc0 created in file dict/dict0dict.c line 1627″ It is index->lock, … the lock for each index tree. We may be able to disperse the lock using by the partitioning of MySQL… segment. The entries are used for consistent reading of the older transactions. They can be …
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 12 Comments
…. For example Innodb tables do internal full table > lock if auto_increment is used so using … problems with loosing data etc. Read more in my > Why MySQL Could be slow with Large Tables… should consider when deciding when / how to create indexes. Foreign key references may add processing time to…
