What is the purpose of partitioning in PostgreSQL?

Partitioning in PostgreSQL is used to divide a large table into smaller, logically related parts — partitions. This improves database performance and manageability.

Main advantages of partitioning:

• Faster queries: with proper configuration, the DBMS only accesses the necessary partitions, reducing the amount of data processed.
• Easier maintenance: old data can be quickly deleted or archived by working with individual partitions.
• Increased scalability: facilitates working with very large tables.

Example of creating a partitioned table by date range:

CREATE TABLE sales (
    id serial PRIMARY KEY,
    sale_date date NOT NULL,
    amount numeric
) PARTITION BY RANGE (sale_date);

CREATE TABLE sales_2023 PARTITION OF sales
    FOR VALUES FROM ('2023-01-01') TO ('2024-01-01');

CREATE TABLE sales_2024 PARTITION OF sales
    FOR VALUES FROM ('2024-01-01') TO ('2025-01-01');

This approach helps efficiently manage data and improve query performance.