Complete Refresh of Materialized View Uses Nested Loops Instead of Hash Joins when Remote Objects Queried over DBLINK
Last updated on AUGUST 12, 2017
Applies to:Oracle Database - Enterprise Edition - Version 18.104.22.168 and later
Information in this document applies to any platform.
The complete refresh of a materialized view with many rows uses nested loops to refresh instead of hash joins. The select statement itself uses hash joins.
Here is an example of an explain plan for the complete refresh. Notice that the estimated cardinality is 1.
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