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Materialized View/
Incremental Materialized View/
Support and Constraints
Updated on 2023-10-23 GMT+08:00
Support and Constraints
Supported Scenarios
- Supports statements for querying a single table.
- Supports UNION ALL for querying multiple single tables.
- Creates an index in the materialized view.
- Performs the Analyze operation in the materialized view.
- Creates an incremental materialized view based on the node group of base tables. (Check whether the base tables are in the same node group and create the incremental materialized view based on the node group).
Unsupported Scenarios
- Materialized views do not support the Stream plan, multi-table join plan, or subquery plan.
- Except for a few ALTER operations, most DDL operations cannot be performed on base tables in materialized views.
- A distribution column of a materialized view cannot be specified when the materialized view is created.
- Materialized views cannot be added, deleted, or modified. Only query statements are supported.
- Materialized views cannot be created using the temporary table, hash bucket, unlog, or partitioned table. Only the hash distribution table is supported.
- 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 is defined as UNION ALL, each subquery must use a different base table and the distribution column of each base table must be the same. The distribution column of the materialized view is automatically deduced and is the same as that of each base table.
- The columns defined in the materialized view must contain all distribution columns in the base table.
- When an incremental 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.
Parent topic: Incremental Materialized View
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