Help Center/ GaussDB/ Developer Guide(Centralized_2.x)/ Materialized View/ Fast-refresh Materialized View/ Support and Constraints
Updated on 2023-10-23 GMT+08:00
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Support and Constraints

Supported Scenarios

  • Supports statements for querying a single table.
  • Supports UNION ALL for querying multiple single tables.
  • Supports index creation in materialized views.
  • Supports the Analyze operation in materialized views.

Unsupported Scenarios

  • Multi-table join plans and subquery plans are not supported in materialized views.
  • Except for a few ALTER operations, most DDL operations cannot be performed on base tables in materialized views.
  • Materialized views cannot be added, deleted, or modified. They support only query statements.
  • The temporary table, hashbucket, unlog, or partitioned table cannot be used to create materialized views.
  • Materialized views cannot be created in nested mode (that is, a materialized view cannot be created in another materialized view).
  • The column-store tables are not supported. Only row-store tables are supported.
  • Materialized views of the UNLOGGED type are not supported, and the WITH syntax is not supported.

Constraints

  • If the materialized view definition is UNION ALL, each subquery needs to use a different base table.
  • When a fast-refresh materialized view is created, fully refreshed, or deleted, a high-level lock is added to the base table. If the materialized view is defined as UNION ALL, pay attention to the service logic to avoid deadlock.