ded698127e
In previous version, if the output slot of analyticExpr is not materialized, the analyticExpr is pruned.
But there are some cases that it cannot be pruned.
For example:
SELECT
count(*)
FROM T1,
(SELECT dd
FROM (
SELECT
1.1 as cc,
ROW_NUMBER() OVER() as dd
FROM T2
) V1
ORDER BY cc DESC
limit 1
) V2;
analyticExpr(ROW_NUMBER() OVER() as dd) is not materialized, but we have to generate
WindowGroup for it.
tmp.dd is used by upper count(*), we have to generate data for tmp.dd
In this fix, if an inline view only output one column(in this example, the 'dd'), we materialize this column.
TODO:
In order to prune 'ROW_NUMBER() OVER() as dd', we need to rethink the rule of choosing a column
for count(*). (refer to SingleNodePlanner.materializeTableResultForCrossJoinOrCountStar)
V2 can be transformed to
SELECT cc
FROM (
SELECT
1.1 as cc,
ROW_NUMBER() OVER() as dd
FROM T2
) V1
ORDER BY cc DESC
limit 1
) V2;
Except the byte size of cc and dd, we need to consider the cost to generate cc and dd.
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