• Data Warehouse Service

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  5. SQL Syntax

SQL Syntax

Structured Query Language (SQL) is the standard language on relational databases (RDB). SQL is a universal and useful RDB language.

Most SQL standards are supported.

The main incompatible items of DWS are as follows:

  • Transaction isolation levels Serializable and Repeatable Read are not supported.
  • Unique constraints take effect only within DNs.
  • The PREPARE statement does not support complex queries.
  • The row-level trigger and COPY cannot be used together.
  • COPY TO cannot use tables distributed in Replication mode.
  • CREATE TABLE AS EXECUTE cannot be used.
  • WHERE CURRENT OF cannot be used.
  • A cursor does not support MOVE BACKWARD.
  • FOREIGN DATA WRAPPER cannot be used.
  • LISTEN, UNLISTEN, and NOTIFY are supported only on CNs.
  • SECURITY LABEL cannot be used.
  • The distribution columns in a table cannot be updated.

For details about error information during SQL execution, see Error Code Reference.