When is materialized view not compatible with base table?

When is materialized view not compatible with base table?

When a materialized view is created on both base tables with timestamp-based materialized view logs and base tables with commit SCN-based materialized view logs, an error (ORA-32414) is raised stating that materialized view logs are not compatible with each other for fast refresh.

Why is materialized view not fast refreshable in Oracle?

The materialized view is not fast refreshable because DML has occurred to a table on which PCT fast refresh is not possible. To avoid this occurring, Oracle recommends performing a fast refresh immediately after any partition maintenance operation on detail tables for which partition tracking fast refresh is available.

How to create a materialized view in SQL Server?

STDEV (a) is specified by users in the SELECT list of a materialized view definition where ‘a’ is an expression. Automatically added by materialized view creation. No user action is required. Once created, materialized views are visible within SQL Server Management Studio under the views folder of the Azure Synapse Analytics instance.

How to re-enable the materialized view in azure?

To re-enable the materialized view, run ALTER MATERIALIZED VIEW with REBUILD. A materialized view in Azure data warehouse is similar to an indexed view in SQL Server. It shares almost the same restrictions as indexed view (see Create Indexed Views for details) except that a materialized view supports aggregate functions.

When to request a complete refresh of a materialized view?

A complete refresh occurs when the materialized view is initially defined as BUILD IMMEDIATE, unless the materialized view references a prebuilt table. For materialized views using BUILD DEFERRED, a complete refresh must be requested before it can be used for the first time.

How does atomic refresh work in materialized views?

Atomic refresh (TRUE or FALSE) If set to TRUE, then all refreshes are done in one transaction. If set to FALSE, then each of the materialized views is refreshed non-atomically in separate transactions.

Can a stale materialized view be used for query rewrite?

Therefore, if you defer refreshing your materialized views, you can either rely on your chosen rewrite integrity level to determine whether or not a stale materialized view can be used for query rewrite, or you can temporarily disable query rewrite with an ALTER SYSTEM SET QUERY_REWRITE_ENABLED = FALSE statement.

What are the benefits of a materialized view?

The ideal materialized views are those that benefit the workload’s performance. For each materialized view, there’s a data storage cost and a cost for maintaining the view. As data changes in base tables, the size of the materialized view increases and its physical structure also changes.

When to use materialized views for performance tuning?

People can use materialized views for query performance tuning, if the cost incurred by the views can be offset by the gain in query performance.

How are job queues used to refresh materialized views?

Job queues can be used to refresh multiple materialized views in parallel. If queues are not available, fast refresh sequentially refreshes each view in the foreground process. To make queues available, you must set the JOB_QUEUE_PROCESSES parameter.