… single query may cause multiple sort buffers to be … tables. The following query creates at least 2 temporary tables: select * from ( select * from (…will also create temp tables; the same applies to views …, 0 rows affected (2.34 sec) mysql> select get_lock(@a, 1); +—————–+ | get_lock(@a…
Post: Investigating MySQL Replication Latency in Percona XtraDB Cluster
March 3, 2013 By 13 Comments
… from 4th server (SMT2) so it is pretty realistic setup from typical data center latency point of view…on multiple nodes. There is an option you can enable to get fully synchronous replication behavior: mysql> set…transactions ? To test this I have created the copy of sbtest table and will run a long …
Post: Why Index could refuse to work ?
September 8, 2006 By 15 Comments
…from the glance view): mysql> explain select * from article where article_id=10; +—-+————-+———+——+—————+——+———+——+——-+————-+ | id | select_type | table… at article table: CREATE TABLE `article` ( `article_id` …there are multiple strings possible …
Post: Full Text Search Webinar Questions Followup
August 24, 2012 By 5 Comments
…create an InnoDB FT index before declaring the `FTS_DOC_ID` primary key column properly, MySQL…asked: Q: If searching on multiple terms, can you get …reindexing the whole dataset from time to time. Mike W… search would necessarily do table-scans. Jessy B. also … of the folks who viewed my Full-Text …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost root Sending data select sql_calc_found_rows * from…” stage – if it is multiple statement transaction. Innodb … written. Created pages is empty pages created in buffer …queries in queue 1 read views open inside InnoDB Main …
Post: Intro to OLAP
July 12, 2010 By 10 Comments
…views to automate that aggregation process. Comparing the performance of OLAP with and without aggregation over multiple MySQL…from the fact table to the dimension tables. A note about degenerate dimensions: Any values in the fact table… You can create multiple different hierarchies from a single …
Post: Fishing with dynamite, brought to you by the randgen and dbqp
November 16, 2011 By Leave a Comment
…From there, we only need to use the following command to execute the test: ./dbqp.py –default-server-type=mysql… package\’s Views translation module.’ The test value was taken from the original bug report…per_table and that we used Xtrabackup’s –parallel option. I also wanted to create multiple …
Post: Can Innodb Read-Ahead reduce read performance ?
June 26, 2007 By 2 Comments
…merged recs, 3876269 merges Hash table size 25499819, used cells…created 2867101, written 37374308 1445.95 reads/s, 0.00 creates… queries in queue 12 read views open inside InnoDB Main … read-ahead performance plus multiple threads doing scattered O… adviseor in this project from MySQL AB side) – to …
