PgConf.Russia 2016

Postgresql's buffer manager has parts where it's showing its age. We'll discuss how it currently works, what problems there are, and what attempts are in progress to rectify its weaknesses.

• Lookups in the buffer cache are expensive
• The buffer mapping table is organized as a hash table, which makes efficient implementations of prefetching, write coalescing, dropping of cache contents hard
• Relation extension scales badly
• Cache replacement is inefficient
• Cache replacement replaces the wrong buffers

CitusDB is an extension for PostgreSQL that can distribute tables across a cluster of PostgreSQL servers. Data is stored in shards that can use append-partitioning for bulk-loading of time series data or hash-partitioning for real-time data ingestion. SELECT queries on distributed tables are transparently parallelised across the cluster, using all available cores. Distributed tables can also be joined in parallel, even if they are not partitioned along the same column. CitusDB is especially suitable for real-time analytics use-cases such as dashboards which require fast analytical queries over live data, and can simultaneously act as a scalable operational database. This talk will describe the internals of CitusDB and give a live demo of a large-scale CitusDB cluster.

Postgres 9.5 adds many features designed to enhance the productivity of developers: UPSERT, CUBE, ROLLUP, JSONB functions, and PostGIS improvements. For administrators, it has row-level security, a new index type, and performance enhancements for large servers. This talk covers the top ten new features that appeared in the Postgres 9.5 release. It will also cover some of the major focuses for post-9.5 releases.

A backup is something that no Postgres deployments should go without as it gives the insurance to get back a deployment on its feet should a disaster strike.

In this talk we will discuss why backups are essential in any sane PostgreSQL deployments (this seems obvious) and what are the different options available to define and set up a good backup strategy. On top of that is discussed how the future of backups would need to be handled, particularly regarding differential backups that gain in popularity among users with large deployments.