The podcast discusses real-time analytics in Postgres, including the challenges of integration and the importance of partitioning and analytics databases. They explore materialized views in real-time analytics and discuss estimates and Autovacuum for performance optimization in Postgres.
Real-time analytics in Postgres can be achieved through the combination of transactional workloads and analytical capabilities or using separate databases.
To improve performance for real-time analytics in Postgres, options such as using column store storage engines like Clickhouse, utilizing foreign data wrappers for offloading load, and implementing partitioning with tools like Timescale are discussed.
Deep dives
Running real-time analytics in Postgres
Running real-time analytics in Postgres is a controversial topic, with a debate between running real-time analytics workloads in combination with transactional workloads or using separate analytical databases. The goal is to achieve better performance by running aggregate queries in a regular OLTP database and potentially eliminating the need for analytical databases like Vertica or Snowflake. However, there are challenges with this approach, as analytical databases are optimized for processing large data volumes and may not perform well with user-facing workloads. Some solutions discussed include the potential for transactional systems to add analytical capabilities and vice versa, as well as the use of hybrid systems that have two separate databases. Additionally, the importance of real-time analytics is highlighted, emphasizing the need for systems that can provide access to data at all times.
Improving performance in Postgres for real-time analytics
To improve performance for real-time analytics in Postgres, there are various approaches discussed in the podcast. These include the use of column store storage engines like Clickhouse, which store each column of a table in a separate file, allowing for efficient extraction and aggregation. Another option is using foreign data wrappers (FDWs) to store old partitions on remote servers, offloading the load from the primary database. The importance of partitioning is also emphasized as a means to improve performance and scalability, and tools like time scale are mentioned as solutions that provide automated partitioning for time-series data. Materialized views are another tool that can assist in optimizing queries, although it's noted that Postgres does not currently have incremental refresh for materialized views.
Considerations and challenges with real-time analytics in Postgres
The podcast discusses additional considerations and challenges when it comes to real-time analytics in Postgres. These include the need to tune autovacuum aggressively to keep visibility maps up to date and benefit from index-only scans. The importance of engineering solutions for challenges that Postgres does not address out of the box is also highlighted, such as asynchronously detached sessions with transactions to denormalize data, incremental updates for materialized views, and automatic partitioning. Additionally, other extensions like HyperLogLog are mentioned as tools that can assist with estimating distinct counts. It's acknowledged that achieving optimal performance for real-time analytics in Postgres can be complex and may require a combination of different approaches and tools.