June 19, 2013

Post: MySQL Query Patterns, Optimized - Webinar questions followup

June 3, 2013 By 2 Comments

… Nearly every solution for randomly choosing rows involves some compromise, either of performance,…and reinitializing the sequence after making certain insert/update/delete operations.  If you have…count the movies per production year for each kind_id. It was more efficient in this case to force MySQL…

Filed Under: Insight for Developers, MySQL, MySQL Webinars Tagged With: , , ,

Post: Is your MySQL buffer pool warm? Make it sweat!

April 16, 2013 By 6 Comments

…1 –mysql-username playback –mysql-password PaSSwOrd –mysql-schema schema_name –query-log-stdin –dispatcher-plugin thread-pool –thread-pool-threads-count 100 –session…is an important step because update statements that match no rows or insert statements that have duplicate key errors may be …

Filed Under: Insight for DBAs, Insight for Developers, MySQL, Percona Software Tagged With: , , , , , , ,

Post: Is Synchronous Replication right for your app?

May 14, 2013 By 18 Comments

…MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL… if( $last_count % 100 == 0 ) { $db->do( “UPDATE achievements SET count = $last_count where achievement = ‘killed_…to update the parent group row so often? INSERT INTO users_groups (user_id, group…

Filed Under: MySQL, Percona Software, XtraDB Cluster Tagged With: , , , , , ,

Post: Benchmarking Percona Server TokuDB vs InnoDB

May 7, 2013 By 32 Comments

…,10000) // distributed by pareto distribution $C, $PAD = random_string() BEGIN INSERT INTO sbtest (id, k, c, pad) VALUES ($ID, $K, $C… dataset. We can easily fill TokuDB tables with 1bln of rows on this SSD, and projected InnoDB performance on this size…/sysbench/insert-roll-2, command line to run: sysbench –test=insert_roll.lua –oltp-table-size=10000 –mysql-user=root –oltp-tables-count=32 –mysql…

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Post: Virident vCache vs. FlashCache: Part 2

May 17, 2013 By 3 Comments

…78GiB of data (32 tables, 10M rows each) and a 4GiB buffer pool…MySQL & Benchmark Configuration All benchmarks were conducted with the following: sysbench ­­–num­-threads=32 ­­–test=tests/db/oltp.lua ­­–oltp_tables_count…1M read_rnd_buffer_size = 4M bulk_insert_buffer_size = 8M myisam_sort_buffer_…

Filed Under: Benchmarks, Hardware and Storage, MySQL Tagged With: , , , , , , ,

Post: Wow. My 6 year old MySQL Bug is finally fixed in MySQL 5.6

August 30, 2012 By 2 Comments

…execution: | Handler_read_next | 1305742982 | mysql> select count(*) from trunc where i=4147483647; +———-+ | count(*) | +———-+ | 0 | +———-+ 1 row in set, 1 warning (0…and the column type was inconsistent between them… so inserts into one table would happen with correct value, such…

Filed Under: Insight for DBAs, MySQL

Post: Ultimate MySQL variable and status reference list

January 8, 2011 By 4 Comments

…MySQL…insert_limitblogpercona.commanual Delayed_insert_threadsblogpercona.commanual delayed_insert…

Filed Under: Insight for DBAs, MySQL

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

…| use_stopword | 1 | | table_state | 0 | +—————————+——–+ 10 rows in set (0.00 sec) mysql> insert into dir_test_innodb (full_name,…_doc_id | 1032677 | | last_optimized_word | | | deleted_doc_count | 0 | | total_word_count | | | optimize_start_time | | | optimize_end_time | | …

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Post: Debugging problems with row based replication

May 6, 2010 By 12 Comments

…02 sec) Insert a single “seed” row into the table: INSERT INTO repl.t1 VALUES (); Query OK, 1 row affected (0.00 sec) INSERT … …play with: select count(*) from t1; +———-+ | count(*) | +———-+ |    65536 | +———-+ 1 row in set (0.02 sec) My test setup includes a MySQL slave.  After …

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Post: The case for getting rid of duplicate “sets”

May 17, 2011 By 2 Comments

… | val | count(*) | +—–+—–+———-+ | 0 | 0 | 1 | +—–+—–+———-+ 1 row in set (0.00 sec) mysql> insert into ex2 values (2,1); Query OK, 1 row affected (0.00 sec) mysql> select a.val, b.val, count(*) from…

Filed Under: MySQL
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