…data = fetchCache(key) if (data) { return data } data = callExpensiveFunction(params) storeCache(data, key) return data…when the entire cache is cleared (think restarting a memcache node). This is where a persistent cache can be invaluable. Enter MySQL…3600, ‘automatic_serialization‘ => true ); $…to…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… MySQL replication? It’s actually much worse than Galera. As I illustrated in a blog post last year, semi-sync must serialize all transactions and wait for them one at a time. So, Callaghan’s law applied to semi-sync is… to replicate your data to a distributed system requires tradeoffs. Most of us are used to the tradeoffs we take when deploying conventional stand-alone MySQL…
Post: When should you store serialized objects in the database?
January 21, 2010 By 47 Comments
… a blog post explaining how they changed from storing data in MySQL columns to serializing data and just storing it inside TEXT/BLOB columns. It… with Ruby gems now around to do this for you automatically. So when is it a good idea to use this technique? If… if you are using a standard serialization technique like JSON it’s difficult to store pieces of data like numbers or IP addresses…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… at the Meta Data Locking behavior prior to MySQL 5.5.3 Metadata Locking behavior prior to MySQL 5.5.3 Prior to MySQL 5.5.3… and contrary to serialization concepts. For example take a look at the following excerpt from the binary log of a case when an… MQ uses MySQL when in HA mode. In HA mode there are two Active MQ servers, both try to do something similar to the…
Post: MySQL 4 to MySQL 5 Upgrade performance regressions
June 6, 2007 By 8 Comments
…two serious performance regression cases when upgrading from MySQL 4.0 and 4.1 to MySQL 5.0. By … which care about their data are typically affected, meaning you have to have innodb_flush_logs_…in MySQL 4.0 and large number of transactions in total so serializing them would make MySQL unable to keep…
Comment: When should you store serialized objects in the database?
January 21, 2010 By 47 Comments
…no other solution than MySQL, or trust it enough. I think where are plenty of cases when storing serialized data makes sense but I…their serialization is really compatible. Manually messing with serialized data is very error prone. When you typically need to access all (or most) of serialized data at…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
… Here is the serial version as run by the native database interface (MySQL): mysql> select word, … intelligent expression substitution to put the results back together, when necessary. When sorting or grouping …work; This allows you to use data flow semantics on any cluster with respect to almost any …
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…data, mostly in one table (lineorder). Each of the 13 queries were executed serially in a single connection I modified the queries to…to be moved to the hot portion. In MySQL 5.5 and earlier, innodb_old_blocks_time defaults to…
Post: Investigating MySQL Replication Latency in Percona XtraDB Cluster
March 3, 2013 By 13 Comments
… to check how Percona XtraDB Cluster behaves when it comes to MySQL replication latency — or better yet, call it data propagation latency. It was interesting to… (even changes to the same table can) but the certification process is serial as well as sending write set to the other nodes…
Post: When would you use SAN with MySQL ?
March 9, 2009 By 18 Comments
…to be serialized. Second, MySQL is often not able to submit a lot of outstanding IO requests which is needed to…to 1TB+ databases. My Take: I view SAN as solution for niche circumstances when it comes to MySQL…
