This page describes how to refresh the PlanCache.
Background information
After an OceanBase cluster is merged, SQL execution plans are regenerated. An execution plan is generated based on the variable values passed when the SQL statement is first executed. The selectivity of these values affects the plan's cost estimation, which can result in a suboptimal execution plan.
When you refresh the PlanCache, all plans are purged from the cache. New execution plans are then generated for subsequent SQL statements. Therefore, refreshing the PlanCache can be used as an emergency measure to resolve this issue.
After you refresh the PlanCache, all SQL statements are immediately reparsed and new execution plans are generated. This process consumes additional CPU resources and may cause fluctuations in database performance. Proceed with caution.
Procedure
Log on to the OceanBase Management Console .
In the navigation pane on the left, click Cluster List.
In the cluster list, select the target cluster and click its name to open the Cluster Workspace.
In the tenant list, click the target tenant to open the Tenant Details page.
In the upper-right corner, click the More icon and select Refresh PlanCache.
In the confirmation dialog box, click OK. This operation may cause fluctuations in database performance. Proceed with caution.
