drill-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From amansinha100 <...@git.apache.org>
Subject [GitHub] drill pull request #519: DRILL-4530: Optimize partition pruning with metadat...
Date Mon, 27 Jun 2016 23:15:11 GMT
Github user amansinha100 commented on a diff in the pull request:

    https://github.com/apache/drill/pull/519#discussion_r68673292
  
    --- Diff: exec/java-exec/src/main/java/org/apache/drill/exec/planner/logical/partition/PruneScanRule.java
---
    @@ -269,13 +283,54 @@ protected void doOnMatch(RelOptRuleCall call, Filter filterRel,
Project projectR
             int recordCount = 0;
             int qualifiedCount = 0;
     
    -        // Inner loop: within each batch iterate over the PartitionLocations
    -        for(PartitionLocation part: partitions){
    -          if(!output.getAccessor().isNull(recordCount) && output.getAccessor().get(recordCount)
== 1){
    -            newPartitions.add(part);
    -            qualifiedCount++;
    +        if (checkForSingle &&
    +            partitions.get(0).isCompositePartition() /* apply single partition check
only for composite partitions */) {
    +          // Inner loop: within each batch iterate over the PartitionLocations
    +          for (PartitionLocation part : partitions) {
    +            assert part.isCompositePartition();
    +            if(!output.getAccessor().isNull(recordCount) && output.getAccessor().get(recordCount)
== 1) {
    +              newPartitions.add(part);
    +              if (isSinglePartition) { // only need to do this if we are already single
partition
    +                // compose the array of partition values for the directories that are
referenced by filter:
    +                // e.g suppose the dir hierarchy is year/quarter/month and the query
is:
    +                //     SELECT * FROM T WHERE dir0=2015 AND dir1 = 'Q1',
    +                // then for 2015/Q1/Feb, this will have ['2015', 'Q1', null]
    --- End diff --
    
    Good point.  The path [2015, null, Jan]  should *not* qualify for the single partition
optimization because in the general case there could be multiple 'Jan' subdirectories under
the dir1 directory.  We would still use the metadata cache but at the level of the dir0, so
ideally one should get cacheFileRoot=/tmp/t2/2015.   I have a fix for this and will update
the PR. 


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message