[
https://issues.apache.org/jira/browse/DRILL-4530?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15339703#comment-15339703
]
ASF GitHub Bot commented on DRILL-4530:
---------------------------------------
Github user jinfengni commented on a diff in the pull request:
https://github.com/apache/drill/pull/519#discussion_r67709299
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/planner/logical/partition/PruneScanRule.java
---
@@ -320,7 +377,17 @@ protected void doOnMatch(RelOptRuleCall call, Filter
filterRel, Project projectR
condition = condition.accept(reverseVisitor);
pruneCondition = pruneCondition.accept(reverseVisitor);
- RelNode inputRel = descriptor.createTableScan(newPartitions);
+ String cacheFileRoot = null;
+ if (checkForSingle && isSinglePartition) {
+ // if metadata cache file could potentially be used, then assign a
proper cacheFileRoot
+ String path = "";
+ for (int j = 0; j <= maxIndex; j++) {
+ path += "/" + spInfo[j];
--- End diff --
Related to Line 313, here we do not check spInfo[j] == null ?
> Improve metadata cache performance for queries with single partition
> ---------------------------------------------------------------------
>
> Key: DRILL-4530
> URL: https://issues.apache.org/jira/browse/DRILL-4530
> Project: Apache Drill
> Issue Type: Improvement
> Components: Query Planning & Optimization
> Affects Versions: 1.6.0
> Reporter: Aman Sinha
> Assignee: Aman Sinha
> Fix For: 1.7.0
>
>
> Consider two types of queries which are run with Parquet metadata caching:
> {noformat}
> query 1:
> SELECT col FROM `A/B/C`;
> query 2:
> SELECT col FROM `A` WHERE dir0 = 'B' AND dir1 = 'C';
> {noformat}
> For a certain dataset, the query1 elapsed time is 1 sec whereas query2
> elapsed time is 9 sec even though both are accessing the same amount of data.
> The user expectation is that they should perform roughly the same. The main
> difference comes from reading the bigger metadata cache file at the root
> level 'A' for query2 and then applying the partitioning filter. query1 reads
> a much smaller metadata cache file at the subdirectory level.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
