SQL Hints
Availability
This feature is available since openGauss 1.1.0.
Introduction
SQL hints can be used to override execution plans.
Benefits
Improves SQL query performance.
Description
In plan hints, you can specify a join order; join, stream, and scan operations, the number of rows in a result, and redistribution skew information to tune an execution plan, improving query performance.
Enhancements
The session-level optimizer parameters can be set by using planhint.
The specified subquery can be not expanded.
GPC can be disabled for a single query.
Constraints
None.
Dependencies
None.
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