PostgreSQL CREATE INDEX: Speed Up Queries on Large Tables

PostgreSQL's CREATE INDEX statement creates an index on one or more table columns to accelerate data retrieval, particularly for queries using WHERE, JOIN, or ORDER BY clauses. This improves query performance and speeds up searches on frequently used columns. The basic syntax is CREATE INDEX index_name ON table_name (column_name), where index_name identifies the index, table_name specifies the target table, and column_name indicates the column to index. Examples include creating a single-column index on CustomerName or a composite index on City and Email columns. Indexes enhance sorting and join operations but require additional storage and maintenance overhead during data modifications. They are most beneficial for large tables with frequent read operations and selective queries.