Robert Haas

PostgreSQL’s query planner attempts to estimate the runtime cost of various plans, but those estimates can be based on statistics which are sometimes misleading and can change over time. This means that the planner will sometimes switch from a good plan that runs quickly to a poor one that runs extremely slowly, sometimes without warning.

PostgreSQL’s query planner attempts to estimate the runtime cost of various plans, but those estimates can be based on statistics which are sometimes misleading and can change over time.

In this talk, I'll discuss the incremental backup feature which I developed for PostgreSQL 17. The talk will discuss how we determine what data has changed, and why the chosen approach was selected.

In this talk, I'll discuss the incremental backup feature which I developed for PostgreSQL 17. The talk will discuss how we determine what data has changed, and why the chosen approach was selected.

In this talk, I'll explain how autovacuum decides which tables to vacuum and analyze and when to perform these operations, with an emphasis on how these algorithms can go wrong. Then, I'll discuss troubleshooting steps that you can take on your system to determine why autovacuum is not performing as expected, as well as how you can fix the problems you might discover.

In this talk, I'll explain how autovacuum decides which tables to vacuum and analyze and when to perform these operations, with an emphasis on how these algorithms can go wrong.

PostgreSQL was designed in a time when software was primarily managed and administered by humans, often humans whose whole job was to keep the computer working. Today, software management is often fully automated.

Assuming no patches are reverted before release, PostgreSQL 15 will feature significant improvements to pg_basebackup and the server-side BASE_BACKUP command which implements it, including server-side compression and backup targets. In this presentation, I'll talk about the work I and others have done to improve the state of pg_basebackup for PostgreSQL 15, and give an overview of...

Hardware or software failure or user error can result in your PostgreSQL database becoming corrupted. In this talk, I'll discuss some things that you can do to minimize the likelihood that your database will become corrupted.

PostgreSQL's EXPLAIN command is a powerful tool, allowing users to expect and understand query plans in detail. However, the output produced by EXPLAIN is not a direct representation of the plan; it omits some information and displays other information in modified form.

Five years after removing SnapshotNow, PostgreSQL still has very little in the way of DDL that can execute concurrently with user queries, and many of the facilities that do exist have significant and sometimes painful limitations. In this talk, I'll give an overview of the problems that have stymied previous attempts to reduce lock levels and design new concurrent DDL facilities.

Over the last several years, PostgreSQL has added multiple ground-breaking capabilities, including parallel query, logical replication, declarative partitioning, and just-in-time compilation.