… is one illustration of group by limitations in SQL language which is not offset by any MySQL specific extensions,yet As you can see if you want to get one row from the group which is sorted… search results by thread and return only one best matching post from each thread while matches themselve could be sorted by relevance or…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
… done through some sort of garbage collection. Support for Delayed Invalidation Many MySQL application do not … rows used from query syntax may be hard. Query Cache Storage Engines MySQL Query Cache now … stats available this can even be done by external script which can have application-specific …
Post: MySQL Error Message Nonsenses
March 16, 2008 By 7 Comments
… in case of syntax error gives you information about tokens near by but little details: mysql> select * from user oder by pwd; ERROR 1064… in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘by pwd’ at… Got Error XYZ from storage engine which could mean all sort of things. For example this may be Operating system specific…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
… and HEAP for in memory tables. So first MySQL versions did not bother naming variables with storage… make sure data hits the disk ft_boolean_syntax, ft_max_word_len, ft_min_word_len,… this variable. sort_buffer_size Buffer used to sort result set (allocated by each thread once sorting needs to be …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –skip-external-locking –port=3306 –socket=/var/db/mysql/mysql… for something strange that might be caused by a syntax error in the my.cnf file. … error log. The error log shows all sorts of interesting things. Basically, anything but silence …
Comment: Database problems in MySQL/PHP Applications
November 6, 2006 By 12 Comments
…mysql.sock #tmpdir =/mysql_tmp/ # Here follows entries for some specific programs # The MySQL server [mysqld] port = 3306 socket = /tmp/mysql…syntax is: # # CHANGE MASTER TO MASTER_HOST=, MASTER_PORT=, # MASTER_USER=, MASTER_PASSWORD= ; # # where you replace , , by quoted strings and # by…
Post: Using Flexviews - part one, introduction to materialized views
March 23, 2011 By 2 Comments
… output of a SQL statement. MySQL even includes a SQL statement…likely expensive. Views containing grouping, aggregation, sorting, distinct or other conditions must…can be used to enhance performance by acting as a cache. Further,…And some drawbacks: Not all SQL syntax supported (no outer join), no non…
