[jira] [Comment Edited] (CALCITE-1777) Druid adapter: "WHERE FALSE" causes AssertionError

["Jesus Camacho Rodriguez (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CALCITE-1777?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16002093#comment-16002093 ] 

Jesus Camacho Rodriguez edited comment on CALCITE-1777 at 5/9/17 8:33 AM:
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[~julianhyde], {{substring}} should not be pushed, as it is not part of the supported operators in _isValidFilter_.

[~bslim], in this specific case, translation was failing because 'false' is a constant and we are assuming that constants can be translated in every case, but actually we cannot translate them if they are at the top level of a predicate. This patch has fixed the 'false' constant issue, but if the constant is 'true' we will face the same problem (probably difficult to reproduce because a filter with condition 'true' will be removed from the operator tree by other rules). IMO the right approach was to fix this in _isValidFilter_ to skip the pushdown translation in these cases, till we have a more robust unified logic like you propose above (which seems a better solution altogether).


was (Author: jcamachorodriguez):
[~julianhyde], {{substring}} should not be pushed, as it is not part of the supported operators in _isValidFilter_.

[~bslim], in this specific case, translation was failing because 'false' is a constant and we are assuming that constants can be translated in every case, but actually we cannot translate them if they are at the top level of a predicate. This patch has fixed the 'false' constant issue, but if the constant is 'true' we will face the same problem (probably difficult to reproduce because a filter with condition 'true' will be removed from the operator tree by other rules). I expect a simple Filter condition CAST on a constant, if it is not folded by other rules, to fail too. IMO the right approach was to fix this in _isValidFilter_ to skip the pushdown translation in these cases, till we have a more robust unified logic like you propose above (which seems a better solution altogether).

> Druid adapter: "WHERE FALSE" causes AssertionError
> --------------------------------------------------
>
>                 Key: CALCITE-1777
>                 URL: https://issues.apache.org/jira/browse/CALCITE-1777
>             Project: Calcite
>          Issue Type: Bug
>            Reporter: Julian Hyde
>            Assignee: slim bouguerra
>             Fix For: 1.13.0
>
>
> Query with "WHERE FALSE" gives AssertionError in Druid adapter.
> Originally logged as part of CALCITE-1775. Test case in {{DruidAdapterIT}}:
> {code}
>   @Test public void testSelectCountFalse() {
>     sql("select count(*) as c from \"foodmart\" where 1 < 0")
>         .returnsUnordered("C=0");
>   }
> {code}
> gives
> {noformat}
> java.lang.AssertionError: cannot translate filter: false
> 	at org.apache.calcite.adapter.druid.DruidQuery$Translator.translateFilter(DruidQuery.java:1067)
> 	at org.apache.calcite.adapter.druid.DruidQuery$Translator.access$000(DruidQuery.java:933)
> 	at org.apache.calcite.adapter.druid.DruidQuery.getQuery(DruidQuery.java:497)
> 	at org.apache.calcite.adapter.druid.DruidQuery.deriveQuerySpec(DruidQuery.java:470)
> 	at org.apache.calcite.adapter.druid.DruidQuery.getQuerySpec(DruidQuery.java:414)
> 	at org.apache.calcite.adapter.druid.DruidQuery.deriveRowType(DruidQuery.java:308)
> 	at org.apache.calcite.rel.AbstractRelNode.getRowType(AbstractRelNode.java:224)
> 	at org.apache.calcite.plan.volcano.VolcanoPlanner.register(VolcanoPlanner.java:857)
> 	at org.apache.calcite.plan.volcano.VolcanoPlanner.ensureRegistered(VolcanoPlanner.java:883)
> 	at org.apache.calcite.plan.volcano.VolcanoPlanner.ensureRegistered(VolcanoPlanner.java:1769)
> 	at org.apache.calcite.plan.volcano.VolcanoRuleCall.transformTo(VolcanoRuleCall.java:135)
> 	at org.apache.calcite.plan.RelOptRuleCall.transformTo(RelOptRuleCall.java:225)
> 	at org.apache.calcite.adapter.druid.DruidRules$DruidFilterRule.onMatch(DruidRules.java:228)
> 	at org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch(VolcanoRuleCall.java:211)
> {noformat}



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