June 18, 2013

Post: Replication in MySQL 5.6: GTIDs benefits and limitations - Part 2

May 30, 2013 By 6 Comments

…shine and where improvements are expected. This is the second post of a series of articles focused on MySQL 5.6 … mysql> change master to master_port=10002; mysql> start slave; # And then check the number of records from the t table s1> select…fixed, it is good to be aware of the current limitations.

Filed Under: Insight for DBAs, MySQL Tagged With: , ,

Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2

April 12, 2013 By 3 Comments

… MySQL transactions started with START TRANSACTION READ ONLY MySQL transactions created by a non-locking SELECT …view sees them or not. The main limitation is obvious: if you want to … We are going to blog about other MySQL performance improvements introduced in our latest Percona Server release…

Filed Under: Benchmarks, MySQL Tagged With: , , ,

Post: Memory allocators: MySQL performance improvements in Percona Server 5.5.30-30.2

April 15, 2013 By

… is another issue in InnoDB transaction processing that notably affects MySQL performance – for every transaction InnoDB creates a read view and… POINT_SELECT test for glibc and jemalloc allocators. Observations: = MySQL 5.5.30 – throughput of MySQL 5.5.30 with glibc is limited first…

Filed Under: Benchmarks, MySQL, Percona Software Tagged With: , , , , , ,

Post: Flexviews - part 3 - improving query performance using materialized views

April 4, 2011 By 20 Comments

…on the MV. mysql> select mview$pk as rank, customer_id, total_price, total_lines from demo.dashboard_top_customers limit 10; +——+————-+————-+————-+ | …ORDER BY or use of NOW(), it but still provides improved performance during refresh by accessing summarized data. I hope …

Filed Under: Insight for DBAs, MySQL

Post: MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown

March 14, 2013 By 2 Comments

… query in particular that had this surprising outcome: mysql> SELECT * FROM cast_info WHERE role_id = 1 and … the new features of MySQL 5.6, and actually is a great improvement over MySQL 5.5. For example, … edge case — but I would call it a limitation of the current query planner. However I would …

Filed Under: Events and Announcements, Insight for Developers, MySQL Tagged With: , ,

Post: Troubleshooting MySQL Memory Usage

March 21, 2012 By 5 Comments

… which allows you to limit size of MEMORY tables (the limit applies both to… tables (both in memory and not): mysql> select * from information_schema.global_temporary_tables \G *************************** 1… hopeful future releases of MySQL, MariaDB or Drizzle bring improvements in this space allowing…

Filed Under: Insight for DBAs, MySQL

Post: Can we improve MySQL variable handling ?

February 18, 2012 By 8 Comments

…-isolation REPEATABLE-READ transaction-prealloc-size 4096 updatable-views-with-limit YES userstat FALSE verbose TRUE wait-timeout 28800 Which is… good idea to extend SELECT syntax to ease querying of variable global value Right now I can select: mysql> select @@global.sort_buffer_size…

Filed Under: MySQL

Post: Shard-Query turbo charges Infobright community edition (ICE)

May 6, 2011 By 23 Comments

… so there are only 29 air carriers in the table: mysql> select count(*), count(distinct UniqueCarrier) from dim_flightG *************************** 1. row *************************** …GROUP BY 1 ORDER BY c LIMIT 10; The next queries show how performance is improved when Shard-Query adds parallelism …

Filed Under: MySQL

Post: Using delayed JOIN to optimize count(*) and LIMIT queries

April 6, 2007 By 22 Comments

…MySQL generates full rows while executing queries with limit …of these so performance improvements can be even higher. CREATE TABLE …mysql> select count(*) from fact; +———-+ | count(*) | +———-+ | 7340032 | +———-+ 1 row in set (0.00 sec) mysql> select count(*) from fact where i select…

Filed Under: Insight for Developers Tagged With: ,

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

February 26, 2013 By 1 Comment

…is this one, which discusses improving bulk insert performance. At the…mysql> set global innodb_optimize_fulltext_only=1; mysql> select * from information_schema.innodb_ft_config; +—————————+——–+ | KEY | VALUE | +—————————+——–+ | optimize_checkpoint_limit…

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