… at the right position, we need to know the whole record R. Also, a gzip compression potentially compresses the database more… code tree by Marko has removed most of the 768 byte local storage in the record. In that source code tree, InnoDB… lots of InnoDB scalability problems from multicore CPU’s. The most recent 5.0.xx behave better. We will continue the scaling…
Comment: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…€œFOR UPDATE†clause does cause a select to read the most recent version, but breaks the rules for repeatable read. The Falcon… worrying about. For real world applications, 95+% of record access is from the record cache, not the page cache. Disk access time…, but we expect that real applications will tend to keep most interesting records in cache.
Comment: Sharing an auto_increment value across multiple MySQL tables
October 5, 2010 By 9 Comments
… to identify insert order, for example to return only N most recent items): create table some_sharded_table( shard_key int, some…_key), data1 int, data2 char(10), … ) You can safely move records between shards, because the primary key includes the directory provided… to get the most recent N rows very efficiently for any shard_key, something that is very common in most sharded applications that…
Comment: Working with many files and file system fragmentation
March 18, 2008 By 11 Comments
… 1 file per filesystem c. recently Mysql 5.1 table partitioning allowed to use SSD for most recent data (most used) and disk for historical data (less used). Index files are the most prone to fragmentation – since 1 record inserted…
Post: Faster MySQL failover with SELECT mirroring
February 1, 2009 By 9 Comments
…-only workload will probably fill the buffer pool with the most recent data; a mixed workload will usually have some different hot…’s overwhelmingly the insert buffer. As Peter explained in his recent post on the insert buffer, the other thing the SELECTs… the insert buffer in a production steady-state. The buffered records are forced to be merged by the SELECTs, and a…
Post: MVCC: Transaction IDs, Log Sequence numbers and Snapshots
December 19, 2007 By 3 Comments
… in the log files and typically incremented for each log record. Innodb uses number of bytes ever written to the log… that. When doing log recovery checking LSN in the log record can tell if you this change needs to be applied… created by transaction 10, deleted by transaction 20. This tracks most recent object history which tells you it was created as value…
Post: Two quick site updates: videos online; Kindle edition
March 22, 2011 By 12 Comments
… site Percona.TV. This includes our recordings from past conferences, user group meetings, screencasts, and most recently our webinars. (I hate the proprietary…
Comment: A rule of thumb for choosing column order in indexes
June 15, 2009 By 15 Comments
…_time) due to a frequent query to get the 50 most recently received items. Average use had about a dozen items sent… has a very different cardinality than the receiver_id and records are generally grouped by a sender as a person can…
Post: Paul McCullagh answers your questions about PBXT
November 20, 2009 By 2 Comments
… in PBXT, and is incremental backup possible? A recent version of PBXT (1.0.09) supports the …, that are responsible for various maintenance tasks. The most important of these are the “Writer”, the “Sweeper” … because a page of records in the table is just a group of records (not an actual fixed …
Post: Using Flexviews - part two, change data capture
March 25, 2011 By 11 Comments
…applications exist for many commercial databases but until recently this type of software was not available for…The Binary Log is the MySQL log which records changes to tables in the database. FlexCDC …. The example settings file should work for most MySQL installations which allow connections as root…
