Amazon Redshift Guide Redshift is NOT PostgreSQL (read first) Redshift speaks PostgreSQL's wire protocol and shares much of its surface syntax, so LLMs assume PostgreSQL behavior carries over — it frequently does not. Divergences span system tables ( is incomplete), DDL (no indexes, no sequences), functions ( , on tables, leader-node-only functions), types (a column becomes VARCHAR(256)), and comparison semantics (trailing blanks, unenforced constraints). Assume divergence and verify against the reference below — do not answer from PostgreSQL habit. Common PostgreSQL→Redshift divergences are…