… pool. The cache devices were flushed to disk immediately prior… be cached (i.e., no special treatment of sequential writes) … of different dirty-page ratios on device performance, since…cache_size = 0 query_cache_type = 0 ft_min_word_len = 4 thread_stack = 192K tmp_table_size = 64M serverid = 101 key…
Post: What MySQL buffer cache hit rate should you target
June 29, 2006 By 5 Comments
… thing which needs to be understand is – cache hit ratio can be computed differently for different engines. For… In partuclar you should be looking at Key_reads and Key_writes for MyISAM tables (note this does not… of them make it to the disk. In some configurations OS cache may take all of them. In…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…writes to the same page, then fewer disk writes are needed. But if your write…disk controller write-back cache does the same thing. PZ: First Indeed writes are slower with Flash disks…, cron, syslog, etc). But the ratio of RAM used for …searches/s HT: Strange, primary key equality searches should work …
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
…offer only incremental performance improvements. key_buffer_size – Very important if…_file_size Very important for write intensive workloads especially for large…disk but only flush it to OS cache. The log is still flushed to the disk…well used. For certain workloads cache hit ratio is lower than would…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…information about last failed foreign key constraint: ———————— LATEST FOREIGN KEY ERROR ———————— 060717 4:29…writes Innodb has to ensure data makes it to the disk – just passing it to OS cache… you can see buffer pool hit ratio which measures buffer pool efficiency. …
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
… physical cores). 12GB memory 4 disk 7200RPM RAID 10 array with 512MB write-back cache Star Schema Benchmark – Scale…that there was a lower buffer pool hit ratio during the MySQL 5.6 runs and … C_MktSegment varchar(10), KEY(C_Name), KEY(C_City), KEY(C_Region), KEY(C_Phone), KEY(C_MktSegment) ); DROP …
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… ICE gets over 16:1 compression ratio(compared to Innodb, 8:1 compared…in memory. This frees disk to use on-disk temporary storage for hash …stats-table innodb-write-io-threads=4 join-buffer-size=16M key-buffer-size…symbolic-links table-definition-cache=16384 table-open-cache=128 thread-cache-size=32 …
Comment: Tokyo Tyrant - The Extras Part II : The Performance Wall
November 11, 2009 By 3 Comments
…ratio value did you use for this test? Though “I use 256M of memory and run my test with writes going directly to disk” confuses me a lot; are … than write performances, wasn’t it? Maybe justing testing reads (on different keys) after a cache purge (like …
