Notice: Much of this post still applies, but now applies more directly to Citus. Since this post originally published, pg_shard is now deprecated. Citus now has an open source version which offer a superset of the features of pg_shard, as well as a cloud offering. Finally you can find some further guidance for sharding on the Citus blog and docs
Back in 2012 I wrote an overview of database sharding. Since then I’ve had a few questions about it, which have really increased in frequency over the last two months. As a result I thought I’d do a deeper dive with some actual hands on for sharding. Though for this hands on, because I do value my time I’m going to take advantage of
pg_shard rather than creating mechanisms from scratch.
For those unfamiliar pg_shard is an open source extension from Citus data who has a commerical product that you can think of is pg_shard++ (and probably much more). Pg_shard adds a little extra to let data automatically distribute to other Postgres tables (logical shards) and Postgres databases/instances (physical shards) thus letting you outgrow a single Postgres node pretty simply.
Alright, enough talk about it, let’s get things up and running.Read on