presenting pg chameleon at the brighton postgresql meetup

Back from Estonia after the amazing European PGConf 2016 I’m about to give a talk on the MySQL to PostgreSQL replication project I’m developing. But first things first. I want to thank all the organisers of the PGConf Europe. The talks were super interesting the location absolutely stunning and the old and new friends I met, remembered me how amazing is the PostgreSQL community. Unfortunately I missed the social events (did somebody said a DBA can have social life?

Directory format and default compression

After upgrading some clusters to PostgreSQL 9.4.4 I noticed an increase of the database backup. Because the databases are quite large I’m taking the advantage of the parallel export introduced with PostgreSQL 9.3. The parallel dump uses the PostgreSQL’s snapshot export with multiple backends. The functionality requires the dump to be in directory format where a toc file is saved alongside with the compressed exports, one per each table saved by pg_dump.

PostgreSQL 8.0, the 2q memory manager

With the revolutionary PostgreSQL 8.0 were introduced a different memory manager, the two queues. This algorithm uses three list of buffer page pointers called cache directory blocks (CDB). The lists T1,T2 are actually pointing buffered pages. B1 lists pages been recently in the shared buffer. Figure 3.1:PostgreSQL 8.0, CDB lists The list T1 is used as LRU for the pages loaded from disk.