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https://issues.apache.org/jira/browse/CALCITE-5240?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17608900#comment-17608900
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Thomas D'Silva commented on CALCITE-5240:
-----------------------------------------
Thanks for the review [~julianhyde].
{quote}
getFloorMod needs to be moved to the right place, and needs its own unit tests.
{quote}
I have removed {{getFloorMod}} as this can just be replaced with
{{startUnit.multiplier}} of a given {{TimeUnitRange}}.
{quote}
It seems that you have added functionality to RexInterpreter. If so, add tests.
{quote}
I have added a test to {{RexProgramTest}} to test the floor and ceil
functionality added to {{RexInterpreter}}.
{quote}
Modifying the materialized view by adding a filter copied from the query seems
like a hack. There seems to be a risk that the filter will be applied twice, or
applied in the wrong place (e.g. to a WHERE clause of a joined table), or a
host of other things. Can you persuade me that it's not a hack?
{quote}
I added a new method {{rewriteInputView}} to {{MaterializedViewAggregateRule}}
that is only implemented in {{MaterializedViewOnlyAggregateRule}}. In
{{MaterializedViewAggregateRule}} the view is rewritten only if there isn't an
existing view predicate and if there is a rollup aggregation on a timestamp
column in the view. In all other cases the existing code flow is maintained.
{quote}
The getViewWithFilter method doesn't seem to me an improvement over the
previous fluent code.
{quote}
I removed {{getViewWithFilter}}.
{quote}
I see that in ImplicitViewPredicateShuttle you transform SEARCH to a boolean
combination of timestamp literals. Did you consider leaving it as SEARCH?
{quote}
Modified {{ImplicitViewPredicateShuttle}} to not transform {{SEARCH}}.
{quote}
As you say, the imports seem to be due to the new class TestRelMdSelectivity
and class TestRelMdRowCount. Is there a better place for those classes to live?
{quote}
Moved {{TestRelMdSelectivity}} and {{TestRelMdRowCount}} to a new class
{{TestMetadataHandlers}}.
> Enhance MaterializedViewRule so that it applies to rollup view for queries
> that contain a predicate on the rollup column
> ------------------------------------------------------------------------------------------------------------------------
>
> Key: CALCITE-5240
> URL: https://issues.apache.org/jira/browse/CALCITE-5240
> Project: Calcite
> Issue Type: Improvement
> Reporter: Thomas D'Silva
> Assignee: Thomas D'Silva
> Priority: Major
> Labels: pull-request-available
> Time Spent: 0.5h
> Remaining Estimate: 0h
>
> {{MaterializedViewRule}} is not applied when a view does not have a view
> predicate but the query contains a predicate. For eg. for the following
> materialized view
> {code:java}
> SELECT eventid, floor(ts to minute), count(*) as cnt
> FROM events
> GROUP BY eventid, floor(ts TO minute)
> {code}
> If we have the following query the view is not used.
> {code:java}
> SELECT floor(ts to minute), count(*)
> FROM events
> WHERE ts > timestamp'2018-01-01 00:02:30' AND ts <= timestamp'2018-01-01
> 00:05:30'
> GROUP BY eventid, floor(ts TO minute)
> {code}
> If {{MaterializedViewRule}} is modified to automatically add the predicate
> {{ts > timestamp'2018-01-01 00:03:00' AND ts < timestamp'2018-01-01
> 00:05:00'}} to the view then the following plan can be generated that uses
> the union rewriting feature to query both the table and the view efficiently.
> {code:java}
> EnumerableAggregate(group=[{0, 1}], EXPR$2=[$SUM0($2)])
> EnumerableUnion(all=[true])
> EnumerableAggregate(group=[{0, 1}], EXPR$2=[COUNT()])
> EnumerableCalc(expr#0..1=[{inputs}], expr#2=[FLAG(MINUTE)],
> expr#3=[FLOOR($t1, $t2)], expr#4=[Sarg[(2018-01-01 00:02:30..2018-01-01
> 00:03:00), [2018-01-01 00:05:00..2018-01-01 00:05:30]]], expr#5=[SEARCH($t1,
> $t4)], eventid=[$t0], $f1=[$t3], $condition=[$t5])
> EnumerableTableScan(table=[[hr, events]])
> EnumerableCalc(expr#0..2=[{inputs}], expr#3=[Sarg[[2018-01-01
> 00:03:00..2018-01-01 00:05:00)]], expr#4=[SEARCH($t1, $t3)],
> proj#0..2=[{exprs}], $condition=[$t4])
> EnumerableTableScan(table=[[hr, MV0]])
> {code}
> The mailing list has a discussion related to this
> [https://lists.apache.org/thread/c7v85fccpbobz44y1o4z7hklomrcl299]
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