Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://amazonaws-china.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). # SQL commands The SQL language consists of commands that you use to create and manipulate database objects, run queries, load tables, and modify the data in tables. Amazon Redshift is based on PostgreSQL. Amazon Redshift and PostgreSQL have a number of important differences that you must be aware of as you design and develop your data warehouse applications. For more information about how Amazon Redshift SQL differs from PostgreSQL, see [Amazon Redshift and PostgreSQL](c_redshift-and-postgres-sql.md). **Note** The maximum size for a single SQL statement is 16 MB. **Topics** + [ABORT](r_ABORT.md) + [ALTER DATABASE](r_ALTER_DATABASE.md) + [ALTER DATASHARE](r_ALTER_DATASHARE.md) + [ALTER DEFAULT PRIVILEGES](r_ALTER_DEFAULT_PRIVILEGES.md) + [ALTER EXTERNAL SCHEMA](r_ALTER_EXTERNAL_SCHEMA.md) + [ALTER EXTERNAL VIEW](r_ALTER_EXTERNAL_VIEW.md) + [ALTER FUNCTION](r_ALTER_FUNCTION.md) + [ALTER GROUP](r_ALTER_GROUP.md) + [ALTER IDENTITY PROVIDER](r_ALTER_IDENTITY_PROVIDER.md) + [ALTER MASKING POLICY](r_ALTER_MASKING_POLICY.md) + [ALTER MATERIALIZED VIEW](r_ALTER_MATERIALIZED_VIEW.md) + [ALTER RLS POLICY](r_ALTER_RLS_POLICY.md) + [ALTER ROLE](r_ALTER_ROLE.md) + [ALTER PROCEDURE](r_ALTER_PROCEDURE.md) + [ALTER SCHEMA](r_ALTER_SCHEMA.md) + [ALTER SYSTEM](r_ALTER_SYSTEM.md) + [ALTER TABLE](r_ALTER_TABLE.md) + [ALTER TABLE APPEND](r_ALTER_TABLE_APPEND.md) + [ALTER TEMPLATE](r_ALTER_TEMPLATE.md) + [ALTER USER](r_ALTER_USER.md) + [ANALYZE](r_ANALYZE.md) + [ANALYZE COMPRESSION](r_ANALYZE_COMPRESSION.md) + [ATTACH MASKING POLICY](r_ATTACH_MASKING_POLICY.md) + [ATTACH RLS POLICY](r_ATTACH_RLS_POLICY.md) + [BEGIN](r_BEGIN.md) + [CALL](r_CALL_procedure.md) + [CANCEL](r_CANCEL.md) + [CLOSE](close.md) + [COMMENT](r_COMMENT.md) + [COMMIT](r_COMMIT.md) + [COPY](r_COPY.md) + [CREATE DATABASE](r_CREATE_DATABASE.md) + [CREATE DATASHARE](r_CREATE_DATASHARE.md) + [CREATE EXTERNAL FUNCTION](r_CREATE_EXTERNAL_FUNCTION.md) + [CREATE EXTERNAL MODEL](r_create_external_model.md) + [CREATE EXTERNAL SCHEMA](r_CREATE_EXTERNAL_SCHEMA.md) + [CREATE EXTERNAL TABLE](r_CREATE_EXTERNAL_TABLE.md) + [CREATE EXTERNAL VIEW](r_CREATE_EXTERNAL_VIEW.md) + [CREATE FUNCTION](r_CREATE_FUNCTION.md) + [CREATE GROUP](r_CREATE_GROUP.md) + [CREATE IDENTITY PROVIDER](r_CREATE_IDENTITY_PROVIDER.md) + [CREATE LIBRARY](r_CREATE_LIBRARY.md) + [CREATE MASKING POLICY](r_CREATE_MASKING_POLICY.md) + [CREATE MATERIALIZED VIEW](materialized-view-create-sql-command.md) + [CREATE MODEL](r_CREATE_MODEL.md) + [CREATE PROCEDURE](r_CREATE_PROCEDURE.md) + [CREATE RLS POLICY](r_CREATE_RLS_POLICY.md) + [CREATE ROLE](r_CREATE_ROLE.md) + [CREATE SCHEMA](r_CREATE_SCHEMA.md) + [CREATE TABLE](r_CREATE_TABLE_NEW.md) + [CREATE TABLE AS](r_CREATE_TABLE_AS.md) + [CREATE TEMPLATE](r_CREATE_TEMPLATE.md) + [CREATE USER](r_CREATE_USER.md) + [CREATE VIEW](r_CREATE_VIEW.md) + [DEALLOCATE](r_DEALLOCATE.md) + [DECLARE](declare.md) + [DELETE](r_DELETE.md) + [DESC DATASHARE](r_DESC_DATASHARE.md) + [DESC IDENTITY PROVIDER](r_DESC_IDENTITY_PROVIDER.md) + [DETACH MASKING POLICY](r_DETACH_MASKING_POLICY.md) + [DETACH RLS POLICY](r_DETACH_RLS_POLICY.md) + [DROP DATABASE](r_DROP_DATABASE.md) + [DROP DATASHARE](r_DROP_DATASHARE.md) + [DROP EXTERNAL VIEW](r_DROP_EXTERNAL_VIEW.md) + [DROP FUNCTION](r_DROP_FUNCTION.md) + [DROP GROUP](r_DROP_GROUP.md) + [DROP IDENTITY PROVIDER](r_DROP_IDENTITY_PROVIDER.md) + [DROP LIBRARY](r_DROP_LIBRARY.md) + [DROP MASKING POLICY](r_DROP_MASKING_POLICY.md) + [DROP MODEL](r_DROP_MODEL.md) + [DROP MATERIALIZED VIEW](materialized-view-drop-sql-command.md) + [DROP PROCEDURE](r_DROP_PROCEDURE.md) + [DROP RLS POLICY](r_DROP_RLS_POLICY.md) + [DROP ROLE](r_DROP_ROLE.md) + [DROP SCHEMA](r_DROP_SCHEMA.md) + [DROP TABLE](r_DROP_TABLE.md) + [DROP TEMPLATE](r_DROP_TEMPLATE.md) + [DROP USER](r_DROP_USER.md) + [DROP VIEW](r_DROP_VIEW.md) + [END](r_END.md) + [EXECUTE](r_EXECUTE.md) + [EXPLAIN](r_EXPLAIN.md) + [FETCH](fetch.md) + [GRANT](r_GRANT.md) + [INSERT](r_INSERT_30.md) + [INSERT (external table)](r_INSERT_external_table.md) + [LOCK](r_LOCK.md) + [MERGE](r_MERGE.md) + [PREPARE](r_PREPARE.md) + [REFRESH MATERIALIZED VIEW](materialized-view-refresh-sql-command.md) + [RESET](r_RESET.md) + [REVOKE](r_REVOKE.md) + [ROLLBACK](r_ROLLBACK.md) + [SELECT](r_SELECT_synopsis.md) + [SELECT INTO](r_SELECT_INTO.md) + [SET](r_SET.md) + [SET SESSION AUTHORIZATION](r_SET_SESSION_AUTHORIZATION.md) + [SET SESSION CHARACTERISTICS](r_SET_SESSION_CHARACTERISTICS.md) + [SHOW](r_SHOW.md) + [SHOW COLUMN GRANTS](r_SHOW_COLUMN_GRANTS.md) + [SHOW COLUMNS](r_SHOW_COLUMNS.md) + [SHOW CONSTRAINTS](r_SHOW_CONSTRAINTS.md) + [SHOW EXTERNAL TABLE](r_SHOW_EXTERNAL_TABLE.md) + [SHOW DATABASES](r_SHOW_DATABASES.md) + [SHOW FUNCTIONS](r_SHOW_FUNCTIONS.md) + [SHOW GRANTS](r_SHOW_GRANTS.md) + [SHOW MODEL](r_SHOW_MODEL.md) + [SHOW DATASHARES](r_SHOW_DATASHARES.md) + [SHOW PARAMETERS](r_SHOW_PARAMETERS.md) + [SHOW POLICIES](r_SHOW_POLICIES.md) + [SHOW PROCEDURE](r_SHOW_PROCEDURE.md) + [SHOW PROCEDURES](r_SHOW_PROCEDURES.md) + [SHOW SCHEMAS](r_SHOW_SCHEMAS.md) + [SHOW TABLE](r_SHOW_TABLE.md) + [SHOW TABLES](r_SHOW_TABLES.md) + [SHOW TEMPLATE](r_SHOW_TEMPLATE.md) + [SHOW TEMPLATES](r_SHOW_TEMPLATES.md) + [SHOW VIEW](r_SHOW_VIEW.md) + [START TRANSACTION](r_START_TRANSACTION.md) + [TRUNCATE](r_TRUNCATE.md) + [UNLOAD](r_UNLOAD.md) + [UPDATE](r_UPDATE.md) + [USE](r_USE_command.md) + [VACUUM](r_VACUUM_command.md)