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https://issues.apache.org/jira/browse/CALCITE-3997?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17109171#comment-17109171
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Xiening Dai commented on CALCITE-3997:
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Hi [~rubenql], I agree with most what you said. We should work out a solution
for this pattern rather than focusing on particular case. At the same time, I
feel it's not a good practice to create rules that match the base class. It's
misleading and error-prone. The original issue is due to FilterJoinRule
matching with Enumerable and wasn't able to process. If one rule matched nodes
with different conventions (it could as it matches base class), there could be
other unexpected results. In mid/long term, I hope we can remove rules matching
base class, and parameterize operand class so downstream system can create
their rule instance per their needs.
Now coming back to transformation rule. This concept is introduced mostly to
facilitate transforming Calcite planner into a Cascade-like optimization
framework. In Cascade search algorithm, relational transformation and
implementation are only done as needed so as to reduce total search space. This
is a key difference between Cascade and Volcano. To implement this, we would
need to keep track of the planning state of each equivalent group, and thus to
distinguish the transformation rule and implementation rules.
I feel this is overall the right direction to evolve Calcite planner. Keeping
backward compatibility is also important but challenging. But I think we can
work out a solution.
> Problem with MERGE JOIN: java.lang.AssertionError: cannot merge join: left
> input is not sorted on left keys
> -----------------------------------------------------------------------------------------------------------
>
> Key: CALCITE-3997
> URL: https://issues.apache.org/jira/browse/CALCITE-3997
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.23.0
> Reporter: Enrico Olivelli
> Priority: Blocker
> Fix For: 1.23.0
>
> Time Spent: 2h 40m
> Remaining Estimate: 0h
>
> I have a couple of problems with HerdDB.
> 1) JOIN order unsorted columns in presence of a WHERE over other columns
> This is my case:
> CREATE TABLE tblspace1.table1 (k1 string primary key,n1 int,s1 string)
> CREATE TABLE tblspace1.table3 (k1 string primary key,n3 int,s3 string)
> SELECT t1.k1 as first, t2.k1 as second
> FROM tblspace1.table1 t1
> INNER JOIN tblspace1.table3 t2 ON t1.k1=t2.k1
> WHERE t1.n1 + 1 = t2.n3
> In this case for table1 and table3 no column is physically sorted (no column
> with a collation)
> I have this Planner error:
> java.lang.AssertionError: cannot merge join: left input is not sorted on left
> keys
> at
> org.apache.calcite.rel.metadata.RelMdCollation.mergeJoin(RelMdCollation.java:457)
> at
> org.apache.calcite.rel.metadata.RelMdCollation.collations(RelMdCollation.java:153)
> at GeneratedMetadataHandler_Collation.collations_$(Unknown Source)
> at GeneratedMetadataHandler_Collation.collations(Unknown Source)
> at
> org.apache.calcite.rel.metadata.RelMetadataQuery.collations(RelMetadataQuery.java:539)
> at
> org.apache.calcite.rel.metadata.RelMdCollation.project(RelMdCollation.java:273)
> at
> org.apache.calcite.rel.logical.LogicalProject.lambda$create$0(LogicalProject.java:122)
> at org.apache.calcite.plan.RelTraitSet.replaceIfs(RelTraitSet.java:242)
> at
> org.apache.calcite.rel.logical.LogicalProject.create(LogicalProject.java:121)
> at
> org.apache.calcite.rel.logical.LogicalProject.create(LogicalProject.java:111)
> at
> org.apache.calcite.rel.core.RelFactories$ProjectFactoryImpl.createProject(RelFactories.java:172)
> at org.apache.calcite.tools.RelBuilder.project_(RelBuilder.java:1464)
> at org.apache.calcite.tools.RelBuilder.project(RelBuilder.java:1258)
> at org.apache.calcite.tools.RelBuilder.project(RelBuilder.java:1230)
> at org.apache.calcite.tools.RelBuilder.project(RelBuilder.java:1219)
> at
> org.apache.calcite.plan.RelOptUtil.pushDownJoinConditions(RelOptUtil.java:3620)
> at
> org.apache.calcite.rel.rules.JoinPushExpressionsRule.onMatch(JoinPushExpressionsRule.java:59)
> at
> org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch(VolcanoRuleCall.java:221)
> at
> org.apache.calcite.plan.volcano.VolcanoPlanner.findBestExp(VolcanoPlanner.java:519)
> at herddb.sql.CalcitePlanner.runPlanner(CalcitePlanner.java:535)
> at herddb.sql.CalcitePlanner.translate(CalcitePlanner.java:292)
> If I remove the "WHERE" clause then no error is reported.
> we have many other test cases about JOINs and this one is the only one that
> fails
> This is the failing test case on HerdDB
> https://github.com/diennea/herddb/blob/vote-calcite-123/herddb-core/src/test/java/herddb/core/SimpleJoinTest.java#L522
> We are using the default set of rules Programs.ofRules(Programs.RULE_SET)
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