…mysql> show global status like ‘wsrep_cluster_size‘; +——————–+——-+ | Variable_name | Value | +——————–+——-+ | wsrep_cluster_size…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…showed MySQL 5.6.10 to be much slower than MySQL…mysql> select * from information_schema.global_status…table_name like ‘%ssb%’ group by 1,2 ) sq order by pct_buffer_pool desc; +——————-+——————+——-+——+——+———+—————–+ | table… POOL_SIZE: 8192 * POOL_SIZE…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… by c_custkey, c_name, c_acctbal, c_phone, n_name, c_address, c_comment order by…by a couple of seconds, when compared to MySQL 5.6. Now let’s take a look at the status counters. MySQL Status Counters These status… the table above you can with default buffer size of 256K, MariaDB 5.5 shows that …
Post: The Optimization That (Often) Isn't: Index Merge Intersection
December 14, 2012 By 6 Comments
…showed that it was the most commonly executed query on the server by two orders… be a one-size-fits-all silver bullet… AND status=1 ORDER BY user_id LIMIT 1; mysql> EXPLAIN…status=1 ORDER BY user_id LIMIT 1\G *************************** 1. row *************************** id: 1 select_type: SIMPLE table…
Post: Air traffic queries in InfiniDB: early alpha
November 2, 2009 By 19 Comments
… to table. But after load, the size of 000.dir is 114G, which is as twice big as original data files. SHOW TABLE STATUS does not really help there, it shows… table at the bottom) Query Q1: mysql> SELECT DayOfWeek, count(*) AS c FROM ontime WHERE Year BETWEEN 2000 AND 2008 GROUP BY DayOfWeek ORDER BY…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 4 Comments
…by l_orderkey, o_orderdate, o_shippriority order by…status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M & read_rnd_buffer_size…size=6M & mrr_buffer_size=6M MariaDB 5.5 Hash Join Disabled w/ join_buffer_size=4M & mrr_buffer_size=4M Created_tmp_disk_tables…
Post: Impact of the sort buffer size in MySQL
October 25, 2010 By 8 Comments
… I pre-warmed the file cache before the benchmark by doing “alter table sorttest engine=myisam;”. The script used for the benchmark….%N` OUT=`mysql -e “set session sort_buffer_size=32*1024*$i;select * from sorttest order by data limit 78000,1;show session status like ‘Sort…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…will give. As “SHOW TABLE STATUS” is not showing index sized in the release …order). In my opinion this however should have been implemented outside of MySQL Storage Engine level for MySQL – reading rows in their physical order…Innodb clustering – users mailbox, clustered by (user_id,message_id). [+] …
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 30 Comments
…tables with varchar/char fields, with small sets of possible values. These are “state”, “gender”, “status…mysql> explain select SQL_NO_CACHE c.city from cities_join c JOIN states s ON (s.id = c.state_id) ORDER BY…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
…29 air carriers in the table: mysql> select count(*), count(distinct UniqueCarrier) from…2008 GROUP BY 1 ORDER BY c LIMIT 10; The next queries show …BY Year) t2 ON (t.Year=t2.Year); The performance of the following queries depends on the size…It is currently approaching RC status. If you decide to test…
