Administration

Tracking Active Vacuum and Autovacuum Workers in PostgreSQL PostgreSQL vacuum is the maintenance process that removes dead tuples left behind by updates and deletes, reclaims storage, and prevents transaction ID wraparound. On active databases, autovacuum runs continuously in the background, but knowing whether it is …

Measuring PostgreSQL Table Cache Efficiency with pg_statio_user_tables PostgreSQL keeps frequently accessed data pages in shared_buffers to avoid hitting disk. When a backend reads a data block, PostgreSQL first checks shared_buffers; if the block is there, it counts as a heap hit. If it is not, PostgreSQL reads from …

Check Replica Identity Settings in PostgreSQL Logical replication in PostgreSQL requires each replicated table to have a replica identity. The replica identity tells PostgreSQL which columns to include in the WAL record for UPDATE and DELETE operations so the subscriber can identify the row being changed. If replica …

List Collations Available in PostgreSQL pg_collation is the system catalog that holds every collation a database can use — the sort-and-compare rules behind ORDER BY, DISTINCT, comparison operators and text indexes. One query against it shows each collation's name, the library that implements it, and the locale it maps …

How to List Installed Extensions in PostgreSQL PostgreSQL extensions package additional functionality — data types, functions, operators, and index methods — that can be installed into a database with CREATE EXTENSION. Common examples include pg_stat_statements for query performance tracking, uuid-ossp for UUID …

How to List PostgreSQL Roles and Privileges Which accounts can log in, which can create databases or other roles, and which are quietly superusers? PostgreSQL answers all three from pg_roles, a view over the role catalog that every user can read. Joined to pg_auth_members it also shows who belongs to which group, and …

Scrubbing Email PII from Your PostgreSQL Database When you copy a production database to a development or test environment, you must remove or anonymize personally identifiable information (PII). Email addresses are among the most common PII fields that need to be scrubbed. Leaving real email addresses in …

Audit Single vs Multi-Column Indexes in PostgreSQL Not all indexes are created equal. A single-column index covers one column and is simple to reason about. A multi-column (composite) index covers two or more columns and can serve a wider range of queries — but only when the leading columns match the query filter. As a …

Monitor PostgreSQL Databases with pg_stat_database pg_stat_database is the database-level statistics view in PostgreSQL. It holds one row per database, and each row carries cumulative counters for transactions, block reads, row activity, temporary files and deadlocks. It is a quick first stop when you want to compare …

Cancel vs Terminate PostgreSQL Backends: What Every DBA Should Know PostgreSQL gives you two tools for dealing with problem backends: pg_cancel_backend() and pg_terminate_backend(). They sound similar but behave very differently. Using the wrong one can disrupt users unnecessarily, or leave a problematic connection in …