VOCABULARY
PostgreSQL Vocabulary & Glossary
Section titled “PostgreSQL Vocabulary & Glossary”Comprehensive Reference of PostgreSQL Terms
Section titled “Comprehensive Reference of PostgreSQL Terms”ACID - Atomicity, Consistency, Isolation, Durability. Four properties that guarantee reliable database transactions.
Analysis - PostgreSQL command that collects statistics about tables for the query planner.
Autovacuum - Background process that automatically runs VACUUM and ANALYZE on tables to reclaim space and update statistics.
Background Writer (bgwriter) - PostgreSQL background process that writes dirty shared buffers to disk.
B-tree - Default index type in PostgreSQL, optimal for equality and range queries.
Buffer Manager - PostgreSQL component that manages shared memory buffers for table and index data.
Checkpoint - Point where all dirty data pages are written to disk and the WAL is flushed.
CIDR - Classless Inter-Domain Routing. Network address type in PostgreSQL.
Cluster - PostgreSQL cluster is a collection of databases managed by a single server instance.
Column - Vertical structure in a table that holds a specific type of data.
COMMIT - Transaction command that makes all changes permanent.
Composite Type - A user-defined type consisting of multiple fields.
Concurrency Control - Methods to ensure correct results when multiple transactions occur simultaneously.
Constraint - Rule enforced on table data (PRIMARY KEY, FOREIGN KEY, UNIQUE, CHECK, NOT NULL).
COPY - PostgreSQL command for fast bulk data import/export.
CTE (Common Table Expression) - Temporary named result set defined within a query.
Database - Organized collection of structured data stored in PostgreSQL.
Dead Tuple - Row version no longer visible to any active transaction, awaiting cleanup.
Domain - User-defined type with constraints.
ENUM - Enumerated type with fixed set of values.
EXPLAIN - Command that shows the execution plan of a query.
EXPLAIN ANALYZE - EXPLAIN with actual execution times and row counts.
Extension - Add-on module that extends PostgreSQL functionality (PostGIS, pg_trgm, etc.).
Foreign Key - Constraint that maintains referential integrity between tables.
Full-Text Search - PostgreSQL feature for searching text data efficiently.
Function - Reusable code block that returns a value.
GIN (Generalized Inverted Index) - Index type for composite values like arrays, JSONB, and full-text search.
GiST (Generalized Search Tree) - Flexible index type for geometric and custom data types.
Grant - Command to give permissions to users/roles.
Heap - Main table storage structure containing row data.
HOT (Heap-Only Tuples) - Optimization that allows index updates without vacuuming.
Identity Column - Column that auto-generates values using a sequence (modern alternative to SERIAL).
Index - Data structure that improves query speed on specific columns.
INET - Network address type for IPv4/IPv6 addresses.
Insert - SQL command to add new rows to a table.
Isolation Level - Setting that determines how transactions see each other’s changes.
JSON - JavaScript Object Notation data type.
JSONB - Binary JSON type with better indexing and query capabilities.
Lock - Mechanism to control concurrent access to database objects.
Log Sequence Number (LSN) - Pointer to position in WAL.
Materialized View - Pre-computed query result stored as a table.
MVCC (Multi-Version Concurrency Control) - Method allowing concurrent transactions without blocking.
NOT NULL - Constraint that prevents NULL values in a column.
Optimizer - PostgreSQL component that determines the most efficient query execution plan.
Page - Basic storage unit in PostgreSQL (typically 8KB).
Partition - Table divided into smaller pieces based on criteria (range, list, hash).
PGDATA - Directory containing PostgreSQL database cluster data files.
pg_hba.conf - Configuration file controlling client authentication.
pg_stat_statements - Extension for tracking query performance statistics.
PostgreSQL - Advanced open-source object-relational database system.
Postmaster - Main PostgreSQL process that manages database cluster.
Primary Key - Unique identifier for each row in a table.
Query Planner - Component that creates execution plans for SQL queries.
Range Type - Data type representing an interval of values.
Read Committed - Default PostgreSQL isolation level.
Replication - Process of copying database data to other servers.
RETURNING - Clause that returns affected rows after INSERT, UPDATE, or DELETE.
REVOKE - Command to remove permissions from users/roles.
Role - Database object that groups privileges.
ROLLBACK - Transaction command that undoes uncommitted changes.
ROW LEVEL SECURITY - Feature that filters rows based on user context.
Schema - Logical container for database objects.
Sequence - Database object that generates auto-incrementing numbers.
Serial - Data type that auto-generates sequential integers.
Shared Memory - Memory area shared by all PostgreSQL processes.
SQL (Structured Query Language) - Language for managing relational databases.
Table - Primary data storage structure with rows and columns.
Tablespace - Location where database objects are stored.
TOAST (The Oversized-Attribute Storage Technique) - Method for storing large values in separate tables.
Transaction - Unit of work that either completely succeeds or fails.
Trigger - Function that automatically executes on certain events.
UUID - Universally Unique Identifier data type.
VACUUM - Command that reclaims storage from dead tuples.
View - Virtual table based on a query.
WAL (Write-Ahead Logging) - Transaction log ensuring durability.
Window Function - Function that performs calculations across related rows.
XID (Transaction ID) - Unique identifier for each transaction.
Last Updated: February 2026