Tag: Open Source

Community

Redundant index is not always bad

(Vadim Tkachenko) About year ago Peter wrote about redundant indexes and mentioned sometimes it is good to leave two indexes, even one is first part of another. I’m speaking about BTREE indexes, for example, KEY (A), and KEY (A,B). From SQL point of view KEY(A) is not needed, as for queries like WHE

Community

Database replication lag

(Dries Buytaert) As explained in an earlier blog post, we recently started using MySQL master-slave replication on drupal.org in order to provide the scalability necessary to accommodate our growing demands. With one or more replicas of our database, we can instruct Drupal to distribute or load bala