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Haisheng Yuan commented on CALCITE-482: --------------------------------------- For hints like {{selectivity}}, a good place to put is the MEMO group, instead of the operator, as long as they are in the same MEMO group, they can share the same property. > Implement sql and planner hints > ------------------------------- > > Key: CALCITE-482 > URL: https://issues.apache.org/jira/browse/CALCITE-482 > Project: Calcite > Issue Type: Bug > Affects Versions: 1.0.0-incubating > Reporter: Vladimir Sitnikov > Assignee: Danny Chan > Priority: Major > Labels: pull-request-available > Time Spent: 2h > Remaining Estimate: 0h > > Query optimizer can never be perfect, so it makes sense to implement hints to > allow user better control the execution. > For instance: "never merge this subquery with others" (`/+ no_merge/`), > "treat those tables as leading ones" (`/*+ leading */`), etc. > Hints would enable predictable performance and the planning time would be > improved as well. -- This message was sent by Atlassian JIRA (v7.6.14#76016)