PostgreSQL Performance Glossary

Complete dictionary of PostgreSQL performance terms, metrics, and concepts with practical examples and detailed explanations.

A

ACID

A set of properties that guarantee database transactions are processed reliably: Atomicity (all operations succeed or fail together), Consistency (data integrity is maintained), Isolation (concurrent transactions don't interfere), and Durability (committed changes persist).

Example: PostgreSQL ensures ACID compliance, making it suitable for financial applications where data integrity is critical.

Atomicity

The property that ensures all operations within a transaction are completed successfully, or none are applied at all.

Example: If transferring money between accounts fails halfway through, atomicity ensures no partial changes are saved.

B

BYOC (Bring Your Own Cloud)

A deployment model where software runs on the customer's own cloud infrastructure rather than the vendor's managed service.

Example: Vela's BYOC approach lets you deploy on AWS, GCP, Azure, or on-premises while maintaining full control.

B-tree Index

A tree data structure that maintains sorted data and allows searches, sequential access, insertions, and deletions in logarithmic time.

Example: PostgreSQL uses B-tree indexes by default for most column types to speed up WHERE clause queries.

C

Copy-on-Write (COW)

A resource management technique where data is shared until one process needs to modify it, then a copy is created.

Example: Vela's copy-on-write cloning allows instant database copies that only use additional storage when data diverges.

Connection Pooling

A technique to maintain a cache of database connections that can be reused across multiple requests.

Example: PgBouncer provides connection pooling to reduce the overhead of establishing new PostgreSQL connections.

Checkpoint

A point in the WAL where all dirty data pages have been written to disk, providing a consistent recovery point.

Example: PostgreSQL automatically performs checkpoints to ensure data durability and limit recovery time.

D

Database Branching

A version control approach for databases that allows creating isolated copies for development, similar to Git branches.

Example: Vela enables database branching so developers can work on features with real production data without affecting the main database.

Durability

The ACID property ensuring that once a transaction is committed, it remains so even in the event of system failure.

Example: PostgreSQL's WAL (Write-Ahead Logging) ensures durability by persisting all changes before acknowledging commits.

E

EXPLAIN ANALYZE

A PostgreSQL command that shows the execution plan of a query along with actual runtime statistics.

Example: EXPLAIN ANALYZE SELECT * FROM users WHERE email = 'user at example.com' shows index usage and execution time.

F

Foreign Key

A constraint that establishes a link between data in two tables by referencing the primary key of another table.

Example: A user_id foreign key in an orders table ensures every order belongs to a valid user in the users table.

Full-Text Search

A technique for searching text data that goes beyond simple pattern matching to include linguistic analysis.

Example: PostgreSQL's full-text search can find documents containing "running" when searching for "run" using stemming.

G

GIN Index

Generalized Inverted Index - an index type in PostgreSQL optimized for indexing composite values like arrays and full-text search.

Example: CREATE INDEX idx_tags ON posts USING GIN(tags) speeds up queries on array columns.

H

Hot Standby

A standby server that can accept read-only queries while continuously applying WAL records from the primary.

Example: PostgreSQL hot standby allows read replicas to serve read traffic while staying synchronized with the primary.

HTAP (Hybrid Transactional/Analytical Processing)

An approach that enables real-time analytics on transactional data without separate ETL processes.

Example: Vela's HTAP capabilities allow running OLAP queries directly on live OLTP data without data movement.

I

Index

A data structure that improves the speed of data retrieval operations on a database table.

Example: CREATE INDEX idx_user_email ON users(email) speeds up login queries that search by email address.

Isolation

The ACID property that ensures concurrent transactions don't interfere with each other.

Example: PostgreSQL's MVCC provides isolation by showing each transaction a consistent snapshot of the database.

J

JSON/JSONB

PostgreSQL data types for storing JSON documents. JSONB is a binary format that supports indexing and efficient operations.

Example: JSONB columns allow storing flexible document data while maintaining the benefits of relational constraints.

L

Lock

A mechanism to control concurrent access to database resources to maintain data consistency.

Example: PostgreSQL uses various lock types to ensure that UPDATE operations don't conflict with each other.

Logical Replication

A method of replicating data changes based on their logical representation rather than physical storage.

Example: Logical replication allows selective replication of specific tables or schemas to different PostgreSQL versions.

M

MVCC (Multi-Version Concurrency Control)

A technique that allows multiple transactions to access the same data simultaneously without blocking.

Example: PostgreSQL's MVCC lets readers and writers operate concurrently without locks by maintaining multiple data versions.

Materialized View

A database object that contains the result of a query and is physically stored, unlike a regular view.

Example: A materialized view can cache complex aggregations for faster reporting queries that don't need real-time data.

O

OLAP (Online Analytical Processing)

A category of database processing that facilitates complex analytical queries over large datasets.

Example: Vela's OLAP capabilities enable real-time business intelligence directly on operational PostgreSQL data.

OLTP (Online Transaction Processing)

A category of database processing that manages transaction-oriented applications with high concurrency.

Example: E-commerce order processing is a typical OLTP workload requiring fast, consistent transactions.

P

pgbench

PostgreSQL's built-in benchmarking tool for running performance tests with simulated workloads.

Example: pgbench -c 10 -j 2 -T 60 mydb runs a 60-second benchmark with 10 clients and 2 worker threads.

Primary Key

A constraint that uniquely identifies each row in a table and cannot contain NULL values.

Example: An auto-incrementing id column is commonly used as a primary key to ensure each record is unique.

Partitioning

A technique to split large tables into smaller, more manageable pieces based on specific criteria.

Example: Range partitioning by date allows efficient querying and maintenance of large time-series tables.

Q

Query Planner

The component of PostgreSQL that determines the most efficient way to execute a given SQL query.

Example: The query planner chooses between index scans and sequential scans based on table statistics and query conditions.

R

Replication

The process of copying and maintaining database objects in multiple database environments.

Example: Streaming replication keeps standby servers synchronized with the primary for high availability.

Real-time Analytics

The ability to analyze data and provide insights immediately as data is created or updated.

Example: Vela enables real-time analytics on live transactional data without traditional ETL delays.

S

SQL (Structured Query Language)

A standardized language for managing and manipulating relational databases.

Example: SELECT name FROM users WHERE created_at > '2023-01-01' retrieves users created this year.

Supabase

An open-source backend platform that provides PostgreSQL database, authentication, and real-time subscriptions.

Example: Vela builds on the Supabase ecosystem, extending it with enterprise features and performance optimizations.

T

TPS (Transactions Per Second)

A key performance metric measuring the number of database transactions completed per second.

Example: Vela achieves 290,000 TPS for read workloads, significantly outperforming traditional cloud databases.

Transaction

A sequence of database operations that are executed as a single logical unit of work.

Example: BEGIN; UPDATE accounts SET balance = balance - 100 WHERE id = 1; UPDATE accounts SET balance = balance + 100 WHERE id = 2; COMMIT;

Time Series

Data organized by time order, typically used for metrics, logs, and sensor data.

Example: PostgreSQL with TimescaleDB extension efficiently handles time-series data for IoT applications.

U

Unified Database

A single database system that can handle multiple workload types (OLTP, OLAP, search, etc.) efficiently.

Example: Vela's unified approach eliminates the need for separate systems for transactional and analytical workloads.

UPSERT

An operation that inserts a new row or updates an existing row if a conflict occurs.

Example: INSERT INTO users (id, name) VALUES (1, 'John') ON CONFLICT (id) DO UPDATE SET name = EXCLUDED.name;

V

VACUUM

A PostgreSQL maintenance operation that reclaims storage and updates statistics for optimal performance.

Example: VACUUM ANALYZE users; reclaims space from deleted rows and updates table statistics for the query planner.

Vector Search

A search technique that finds similar items based on vector embeddings, commonly used for AI applications.

Example: PostgreSQL with pgvector extension enables semantic search and recommendation systems using vector similarity.

Vela

A high-performance PostgreSQL platform with instant cloning, Git-like branching, and unified OLTP/OLAP capabilities.

Example: Vela provides 6x better performance than AWS RDS while offering modern development workflows developers love.

W

WAL (Write-Ahead Logging)

A logging mechanism where changes are written to a log before being applied to the database files.

Example: WAL ensures data durability and enables point-in-time recovery and streaming replication in PostgreSQL.

WHERE Clause

A SQL clause used to filter records based on specified conditions.

Example: SELECT * FROM products WHERE price > 100 AND category = 'electronics' filters products by price and category.