…for those using MySQL, Percona Server, MariaDB or any other of the MySQL branches/forks, you get to have …)+2) (bytes) + length of all comments (in bytes) + length of all intervals (for ENUM, SET) in bytes…columns in a MySQL table. So what’s the maximum number of columns in a MySQL table? Well.. I …
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…get to disk. This has no effect on standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL… in separate tables and there also exists a users_groups table to define the…retry_autocommit If your hotspots are all updates with autocommits, you can…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
…, unlike anything you find in standard async MySQL replication. It is my belief that the…get behind? As I’ve mentioned before, Galera’s replication is synchronous to the point of ensuring transactions are copied to all…the certification index, which is a hash table. A small fc_limit does however keep…
Post: How to recover table structure from InnoDB dictionary
April 22, 2013 By 4 Comments
…gets created it will have minimal `ID` among the indexes of the table. mysql> select * from SYS_INDEXES WHERE TABLE_ID=741; +———-+——+———————+———-+——+——-+———+ | TABLE…
Comment: How to recover table structure from InnoDB dictionary
May 8, 2013 By 4 Comments
…per_table is OFF by default, which means all tables are in ibdata1. 2) if it was…tables structure you can get from the dictionary as it is described here. Once you have the structure you can get your tables…for each table – http://www.percona.com/docs/wiki/innodb-data-recovery-tool:mysql-data-recovery…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… one interesting item here is that vCache actually appears to get *better* over time; I’m not entirely sure why that…. Base MySQL & Benchmark Configuration All benchmarks were conducted with the following: sysbench –num-threads=32 –test=tests/db/oltp.lua –oltp_tables_count…=0 –percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-engine=innodb \ –oltp-read-only=off run The base MySQL configuration (configuration A…
Comment: Follow these basics when migrating to Percona XtraDB Cluster for MySQL
May 7, 2013 By 10 Comments
… not get any error as such, it is just that the data are not getting updated in all the tables and only few tables are getting… process on our Development server which is still running on MYSQL and it worked fine.
Comment: Solving INFORMATION_SCHEMA slowness
May 6, 2013 By 25 Comments
…is caused by bug #56178 then you must run MySQL 5.5 to get te fix. It might be possible, however, … write a function to discover the structure of a table, its columns and primary key, etc. Using I_S … for “SHOW COLUMNS FROM “). That has less information than all of I_S, but it was sufficient for what …
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…TABLE_LIST*, Item*) (sql_show.cc:5522) ==9090== by 0x74E4DF: get_schema_tables_result(JOIN*, enum_schema_table_state) (sql_show.cc:6238) ==9090== by 0x6A5E0C: JOIN::exec() (sql_select.cc:1863) ==9090== by 0x6A7D72: mysql_select(THD*, Item***, TABLE… main (mysqld.cc:4504) All previous …
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… for given table. Instead we could track versions for tables (increment each time table is updated) and check whenever version matches for all tables on… presented as some INFORMATION_SCHEMA tables. Self Refresh MySQL Query Cache causes not uniform performance as you get very fast responses for hits…
