Top n push down #110
Top n push down #110
Conversation
|
Refer to client PR: #178 |
| case PhysicalOperation(projectList, filters, LogicalRelation(source: TiDBRelation, _, _)) | ||
| if filters.forall(TiUtils.isSupportedFilter(_, source)) => | ||
| pruneTopNFilterProject(limit, projectList, filters, source) :: Nil | ||
| case TiAggregation( |
There was a problem hiding this comment.
Would you please confirm if topN and aggregates can be pushdown independently.
For example, if you have group by name and count
you have
region 1: A, 100, B, 1
region 2: A, 100, B 1000
and you take Top 1. In above case, B will be ignored in region 1 request but actually B is the group to take and final result is 1000 instead of 1001.
I wonder if above case works in your implementation.
| ) | ||
| } | ||
|
|
||
| def validGroupAggregate(groupingExpressions: Seq[NamedExpression], |
There was a problem hiding this comment.
Change it to isValidAggregates. Aggregates include aggexpr and groupby exprs.
| aggregate.AggUtils.planAggregateWithoutDistinct( | ||
| ) if validGroupAggregate(groupingExpressions, aggregateExpressions, source) => | ||
| val dagReq: TiDAGRequest = filterToDAGRequest(filters, source) | ||
| groupAggregateProjection( |
|
@ilovesoup Sorry for the inconvenience I bought, this PR only handles TopN logic but not aggregation with TopN logic. |
|
Integration test result: |
Support for
Limitandorder byclause.