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https://issues.apache.org/jira/browse/CALCITE-3928?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17089233#comment-17089233
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xzh_dz commented on CALCITE-3928:
---------------------------------
Follow [[email protected]] illustrated, A case as below:
{code:java}
query:
LogicalAggregate(group=[{4}], agg#0=[COUNT($3)])
LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], SAL=[$5], DEPTNO=[$7])
LogicalTableScan(table=[[scott, EMP]])
mv logic:
LogicalAggregate(group=[{1}], agg#0=[COUNT($0)])
LogicalProject(SAL=[$5], DEPTNO=[$7])
LogicalTableScan(table=[[scott, EMP]])
{code}
query has the same semantics with mv logic. Materialization reconginze will be
failed because the mv logic unable to express query.
So we should try to add the field trimming for canonicalizing.
> Canonicalization doesn't do field trimming before materialized view matching
> ----------------------------------------------------------------------------
>
> Key: CALCITE-3928
> URL: https://issues.apache.org/jira/browse/CALCITE-3928
> Project: Calcite
> Issue Type: Bug
> Reporter: Jin Xing
> Priority: Major
> Labels: materializedviews
>
> If we have query and materialized view as below:
> {code:java}
> query:
> LogicalAggregate(group=[{0}], EXPR$1=[afunc($1, $1)])
> LogicalProject(a=$0, b=[bfunc($1)])
> LogicalTableScan(table=[[default, user_table]])
> mv:
> LogicalAggregate(group=[{0}], EXPR$1=[afunc($1, $2)])
> LogicalProject(a=$0, b=[bfunc($1)], c=[bfunc($1)])
> LogicalTableScan(table=[[default, user_table]])
> {code}
> The semantics of query and mv logic are the same. Materialized view matching
> failed, because field trimming is not done when canonicalizing the plans.
> Currently Calcite does field trimming when convert sql to rel. But my
> company's internal system does materialization detection – – generates &
> transforms & stores the RelNode.
> Shall we add the field trimming when canonicalizing materialized view logic?
>
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