…: mysql> SELECT SQL_NO_CACHE SQL_CALC_FOUND_ROWS * FROM count_test WHERE b = 555 ORDER BY c LIMIT 5; Results with SQL_CALC_FOUND_ROWS are…-100 sec). Let’s take a look at EXPLAINs: mysql> explain SELECT SQL_CALC_FOUND_ROWS * FROM count_test WHERE b = 999 ORDER BY… seconds for SQL_CALC_FOUND_ROWS. 7+7 seconds in case when two queries used. Filesort: 1.8 seconds for SQL_CALC_FOUND_ROWS. 1.8…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… 442 mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost root Sending data select sql_calc_found_rows * from… 166 mysql tables in use 1, locked 0 MySQL thread id 8078, query id 728898 localhost root Sending data select sql_calc_found_rows * from… 114 mysql tables in use 1, locked 0 MySQL thread id 8077, query id 728897 localhost root Sending data select sql_calc_found_rows * from…
Comment: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
August 29, 2007 By 57 Comments
… SELECT SQL_CALC_FOUND_ROWS * FROM count_test WHERE b = 999 ORDER BY c LIMIT 5;”, mysql uses index to determine number of rows to… columns are not included in index). I think use SQL_CALC_FOUND_ROWS in queries that use complex where (for example search queries… the same thing but one with SQL_CALC_FOUND_ROWS just stores number of records before restricting rows. If I am wrong, please clarify…
Comment: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
August 30, 2007 By 57 Comments
… ago and found the same: SQL_CALC_FOUND_ROWS was always much slower than two queries. The reason appears to be that MySQL does a good job of optimizing LIMIT queries by stopping them when the desired number of rows has been found. Using SQL_CALC_FOUND_ROWS…
Comment: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
November 27, 2008 By 57 Comments
…sql = “SELECT FOUND_ROWS()”; $rows_count = $this->fetchOne($sql); ?> åŽè®°ï¼šè¿™ç§æ–¹…§ï¼šhttp://www.mysqlperformanceblog.com/2007/08/28/to-sql_calc_found_rows-or-not-to-sql_calc_found_rows/ Mysql [...]
Comment: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
September 11, 2009 By 57 Comments
… have to use mysql_num_rows or SQL_CALC_FOUND_ROWS , mysql_num_rows runs very slow. we have only one option it is SQL_CALC_FOUND_ROWS. if any…
Comment: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
August 29, 2007 By 57 Comments
… of mysql server did you use? Does this apply to all current versions or is the SQL_CALC_FOUND_ROWS option more optimized in mysql 5 ? Depending on the availability of indexes, mysql should be able to optimize a SQL_CALC_FOUND_ROWS query…
Comment: Four ways to optimize paginated displays
September 24, 2008 By 27 Comments
… many pages the results set will span?: { 1. SELECT SQL_CALC_FOUND_ROWS id FROM table ORDER BY foo LIMIT offset, size 2…. re-arrange ids 5.SELECT FOUND_ROWS(); 1 usually requires as little time as possible for mySQL will usually consult the index fetching… little time as it could take; mySQL can fetch the record information for the rows required as efficiently as it could ( i…
Post: Is it query which needs to be optimized ?
March 6, 2007 By 9 Comments
… I had a lot of a lot of questions at MySQL Performance Forum as well as from our customers regarding query… for large number of rows you’ve simply got to use different solutions, such as summary table. With MySQL 5.0 it… number of rows in result set, with results set of 100.000+ it becomes pretty inefficient. There is surely SQL_CALC_FOUND_ROWS but…
Comment: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
September 12, 2009 By 57 Comments
… the mysql official documentation here http://dev.mysql.com/doc/refman/5.1/en/information-functions.html Please have a look at FOUND_ROWS() function. They have mentioned that it is much faster to use the query with sql_calc_found_rows rather than…
