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https://issues.apache.org/jira/browse/IGNITE-14277?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Konstantin Orlov updated IGNITE-14277:
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Description:
Currently SqlToRelConverter rewrites queries with IN predicate into semi-join
but without actually using semi-join. The resulting plan includes two joins and
several aggregates over IN argument list to calculate some sort of indicators.
This plan is quite cumbersome, it contains a lot of nodes, thus boost a search
space.
As workaround this optimization was disabled by increasing inSubQueryThreshold
to a MAX_INT value.
But a safer solution would be to rewrite the IN predicate as a true semi-join,
or better yet, an inner join. To achieve this, we need to convert the list of
values to an inline table with only distinct values as the left shoulder of the
inner join, and place the original table as the right shoulder. Thus, we could
take advantage of the Indexed Nested Loop in case there is an index on a column
that is part of the IN predicate.
Starting point for this ticket is
{{org.apache.calcite.sql2rel.SqlToRelConverter#substituteSubQuery}}
was:
Currently SqlToRelConverter rewrites queries with IN predicate into semi-join
but without actually using semi-join. The resulting plan includes two joins and
several aggregates over IN argument list to calculate some sort of indicators.
This plan is quite cumbersome, it contains a lot of nodes, thus boost a search
space.
As workaround this optimization was disabled by increasing inSubQueryThreshold
to a MAX_INT value.
But a safer solution would be to rewrite the IN predicate as a true semi-join,
or better yet, an inner join. To achieve this, we need to convert the list of
values to an inline table with only single values as the left shoulder of the
inner join, and place the original table as the right shoulder. Thus, we could
take advantage of the Indexed Nested Loop in case there is an index on a column
that is part of the IN predicate.
Starting point for this ticket is
{{org.apache.calcite.sql2rel.SqlToRelConverter#substituteSubQuery}}
> Calcite. Rewrite IN predicate to semi-join
> ------------------------------------------
>
> Key: IGNITE-14277
> URL: https://issues.apache.org/jira/browse/IGNITE-14277
> Project: Ignite
> Issue Type: Improvement
> Components: sql
> Reporter: Konstantin Orlov
> Priority: Major
>
> Currently SqlToRelConverter rewrites queries with IN predicate into semi-join
> but without actually using semi-join. The resulting plan includes two joins
> and several aggregates over IN argument list to calculate some sort of
> indicators. This plan is quite cumbersome, it contains a lot of nodes, thus
> boost a search space.
> As workaround this optimization was disabled by increasing
> inSubQueryThreshold to a MAX_INT value.
> But a safer solution would be to rewrite the IN predicate as a true
> semi-join, or better yet, an inner join. To achieve this, we need to convert
> the list of values to an inline table with only distinct values as the left
> shoulder of the inner join, and place the original table as the right
> shoulder. Thus, we could take advantage of the Indexed Nested Loop in case
> there is an index on a column that is part of the IN predicate.
>
> Starting point for this ticket is
> {{org.apache.calcite.sql2rel.SqlToRelConverter#substituteSubQuery}}
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