… compared to MySQL 5.5 While with join_buffer_size set to 6M and read_rnd_buffer_size set to 6M, the query time for MySQL 5.6 becomes approximately equal to that of MySQL… MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M & read_rnd_buffer_size=6M MariaDB 5.5 MariaDB 5.5 w/ join_buffer_size=6M & mrr_buffer_size…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…, and N is the buffer size. In MySQL 5.6 the buffer size used by MRR can be controlled by the variable read_rnd_buffer_size, while MariaDB introduces a different variable to control the MRR buffer size mrr_buffer_size. Both buffer sizes default to 256K in MySQL 5.6…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…
Post: What exactly is read_rnd_buffer_size
July 24, 2007 By 4 Comments
… for documentation for read_rnd_buffer_size you would find descriptions such as “The read_rnd_buffer_size is used after a sort, when reading rows in sorted…physical) order. MySQL takes bunch of pointers from sort_buffer (just enough so all rows fit in read_rnd_buffer as they are read) and sorts…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… referring to the amazing MySQL manual, especially the option and variable reference table. ….commanual range_alloc_block_sizeblogpercona.commanual read_buffer_sizeblogpercona.commanual read_onlyblogpercona.commanual read_rnd_buffer_sizeblogpercona.commanual relay_logblogpercona.commanual relay…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
…read_buffer_size, read_rnd_buffer_size – Variables used as read buffer for MyISAM tables for Full Table Scan (read_buffer) and for reading rows in sorted order (read_rnd_buffer_size…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…socket=/tmp/mysql-inno.sock [mysqld] socket=/tmp/mysql-inno.sock default-storage-engine=INNODB innodb-buffer-pool-instances=2 innodb-buffer-pool-size=…level=0 partition=ON port=3306 read-buffer-size=512K read-rnd-buffer-size=1M skip-host-cache skip-name-resolve sort-buffer-size=512K sql-mode=STRICT_…
Post: MySQL Server Memory Usage
May 17, 2006 By 18 Comments
…buffer_size, query_cache_size. If you’re using MyISAM seriously you can also add the size of Operation System cache you would like MySQL… sorts, or need temporary tables as much as read_buffer_size, sort_buffer_size, read_rnd_buffer_size, tmp_table_size of memory might be allocated. But they are only…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
… = 6000 read_rnd_buffer_size = 2M sort_buffer_size = 32k thread_cache = 16 query_cache_size = 0M thread_concurrency = 8 max_heap_table_size=200M log…/log/mysql/var/ innodb_checksums = 0 innodb_doublewrite = 0 innodb_buffer_pool_size = 5000m innodb_additional_mem_pool_size = 20M innodb_log_file_size =…
Post: Are larger buffers always better ?
June 6, 2006 By 9 Comments
… and some 10 distinct c values. read_buffer_size and read_rnd_buffer_size – These are buffers used by MyISAM to perform reads, in different scenarios. So should we… 5 MyISAM will allocate the buffer and populate if fully when MySQL will read only 5 rows from the buffer and throw away the…
