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Posted to issues@calcite.apache.org by "zhen wang (JIRA)" <ji...@apache.org> on 2018/03/08 10:00:01 UTC
[jira] [Commented] (CALCITE-1862) StackOverflowException in
RelMdUtil.estimateFilteredRows
[ https://issues.apache.org/jira/browse/CALCITE-1862?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16391001#comment-16391001 ]
zhen wang commented on CALCITE-1862:
------------------------------------
some findings
the estimate row count method it self is actually okay. before planner optimization it can derive the correct row count
the problem lies in the optimization, as rules gets applied on the relation algebra, the plan becomes deeper and deeper, when the stack overflow, the algebra has grown to a depth > 100 which essentially lead to the stack overflow.
haven't located which rule is actually leading to the growth of the relation algebra.
> StackOverflowException in RelMdUtil.estimateFilteredRows
> --------------------------------------------------------
>
> Key: CALCITE-1862
> URL: https://issues.apache.org/jira/browse/CALCITE-1862
> Project: Calcite
> Issue Type: Bug
> Reporter: Julian Hyde
> Assignee: Julian Hyde
> Priority: Major
>
> The query
> {code}select *
> from (
> select *
> from (
> select cast(null as integer) as d
> from "scott".emp)
> where d is null and d is null)
> where d is null;{code}
> gives
> {noformat}
> java.lang.StackOverflowError
> > at org.apache.calcite.adapter.clone.ArrayTable.getStatistic(ArrayTable.java:76)
> > at org.apache.calcite.prepare.RelOptTableImpl.getRowCount(RelOptTableImpl.java:224)
> > at org.apache.calcite.rel.core.TableScan.estimateRowCount(TableScan.java:75)
> > at org.apache.calcite.rel.metadata.RelMdRowCount.getRowCount(RelMdRowCount.java:206)
> > at GeneratedMetadataHandler_RowCount.getRowCount_$(Unknown Source)
> > at GeneratedMetadataHandler_RowCount.getRowCount(Unknown Source)
> > at org.apache.calcite.rel.metadata.RelMetadataQuery.getRowCount(RelMetadataQuery.java:236)
> > at org.apache.calcite.rel.metadata.RelMdRowCount.getRowCount(RelMdRowCount.java:71)
> > at GeneratedMetadataHandler_RowCount.getRowCount_$(Unknown Source)
> > at GeneratedMetadataHandler_RowCount.getRowCount(Unknown Source)
> > at org.apache.calcite.rel.metadata.RelMetadataQuery.getRowCount(RelMetadataQuery.java:236)
> > at org.apache.calcite.rel.metadata.RelMdUtil.estimateFilteredRows(RelMdUtil.java:718)
> > at org.apache.calcite.rel.metadata.RelMdRowCount.getRowCount(RelMdRowCount.java:123)
> > at GeneratedMetadataHandler_RowCount.getRowCount_$(Unknown Source)
> > at GeneratedMetadataHandler_RowCount.getRowCount(Unknown Source)
> > at org.apache.calcite.rel.metadata.RelMetadataQuery.getRowCount(RelMetadataQuery.java:236)
> > at org.apache.calcite.rel.metadata.RelMdRowCount.getRowCount(RelMdRowCount.java:71)
> > at GeneratedMetadataHandler_RowCount.getRowCount_$(Unknown Source)
> > at GeneratedMetadataHandler_RowCount.getRowCount(Unknown Source)
> > at org.apache.calcite.rel.metadata.RelMetadataQuery.getRowCount(RelMetadataQuery.java:236)
> > at org.apache.calcite.rel.metadata.RelMdUtil.estimateFilteredRows(RelMdUtil.java:718){noformat}
> For a test case, add the query to misc.iq and run QuidemTest.
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