…table2. Of course this could mean a lot of random lookups in case the dataset does not fit …Scan disabled, and the only difference in query time is 48.78s vs 48.91s, so I don’t …to become sequential. The two other most important numbers are values for Innodb_buffer_pool_reads and Innodb_data_read. We…
Post: InnoDB: look after fragmentation
November 5, 2009 By 12 Comments
…` int(10) unsigned default NULL, PRIMARY KEY (`tracker_id`,`username`,`time_id`), KEY `block_id` (`block_id`) ) ENGINE=InnoDB Table has… extended stats: # Query_time: 17.765369 Lock_time: 0.000137 Rows_sent: 1 Rows_examined: 11569733 Rows_affected: 0 Rows_read: 11569733 # InnoDB…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…1.xx. PZ: I should note MySQL 5.0 vs 4.1 has a lot of performance differences …random writes to them are actually slower than to a mechanical disk. I do not know how it is for sequential…out one at a time, that are esentially reads misses (10ms each). The reads are not excactly sequential, there is a …
Comment: Linux schedulers in tpcc like benchmark
January 31, 2009 By 19 Comments
…from sequentially written log files to the more write-costly spreaded/random …vs. worst case latencies vs. throughput, which sometimes does matters. I suspect a mixed workload (alternated write intensives, reads…time to completion (so, latency). I mean workloads including possibles concurrents reads…
Comment: High-Performance Click Analysis with MySQL
December 23, 2008 By 13 Comments
…MyISAM. 2) Real time vs delayed. I think for many applications semi-real time is a value…random lookups but you need to keep the balance of keeping data compact. 4) MyISAM vs Innodb – if you have read… database (MyISAM surely will be bound by sequential disk writes) – this gives convenience of running…
