[GitHub] drill pull request: DRILL-3884: Fix lower parallelization issues w...
Github user asfgit closed the pull request at: https://github.com/apache/drill/pull/185 --- 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 infrastruct...@apache.org or file a JIRA ticket with INFRA. ---
[GitHub] drill pull request: DRILL-3884: Fix lower parallelization issues w...
Github user amansinha100 commented on the pull request: https://github.com/apache/drill/pull/185#issuecomment-144884113 +1 LGTM. --- 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 infrastruct...@apache.org or file a JIRA ticket with INFRA. ---
[GitHub] drill pull request: DRILL-3884: Fix lower parallelization issues w...
Github user vkorukanti commented on a diff in the pull request:
https://github.com/apache/drill/pull/185#discussion_r40982402
--- Diff:
contrib/storage-hive/core/src/main/java/org/apache/drill/exec/store/hive/HiveScan.java
---
@@ -319,16 +319,12 @@ public ScanStats getScanStats() {
estRowCount = data/1024;
}
- // Hive's native reader is neither memory efficient nor fast. If the
rowcount is below
- // HIVE_SERDE_SCAN_OVERHEAD_FACTOR, make sure it is at least
HIVE_SERDE_SCAN_OVERHEAD_FACTOR to enable the planner
- // to choose HiveDrillNativeParquetScan. Due to the project on top
of HiveDrillNativeParquetScan, we end up
- // choosing the HiveScan instead of HiveDrillNativeParquetScan if
the cost is too low.
- if (estRowCount <= HIVE_SERDE_SCAN_OVERHEAD_FACTOR) {
-estRowCount = HIVE_SERDE_SCAN_OVERHEAD_FACTOR;
- }
+ // Hive's native reader is neither memory efficient nor fast.
Increase the CPU cost
+ // by a factor to let the planner choose HiveDrillNativeScan over
HiveScan with SerDes.
+ float cpuCost = 1 * HIVE_SERDE_SCAN_OVERHEAD_FACTOR;
--- End diff --
Fixed in updated patch.
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[GitHub] drill pull request: DRILL-3884: Fix lower parallelization issues w...
Github user amansinha100 commented on a diff in the pull request:
https://github.com/apache/drill/pull/185#discussion_r40981727
--- Diff:
contrib/storage-hive/core/src/main/java/org/apache/drill/exec/store/hive/HiveScan.java
---
@@ -319,16 +319,12 @@ public ScanStats getScanStats() {
estRowCount = data/1024;
}
- // Hive's native reader is neither memory efficient nor fast. If the
rowcount is below
- // HIVE_SERDE_SCAN_OVERHEAD_FACTOR, make sure it is at least
HIVE_SERDE_SCAN_OVERHEAD_FACTOR to enable the planner
- // to choose HiveDrillNativeParquetScan. Due to the project on top
of HiveDrillNativeParquetScan, we end up
- // choosing the HiveScan instead of HiveDrillNativeParquetScan if
the cost is too low.
- if (estRowCount <= HIVE_SERDE_SCAN_OVERHEAD_FACTOR) {
-estRowCount = HIVE_SERDE_SCAN_OVERHEAD_FACTOR;
- }
+ // Hive's native reader is neither memory efficient nor fast.
Increase the CPU cost
+ // by a factor to let the planner choose HiveDrillNativeScan over
HiveScan with SerDes.
+ float cpuCost = 1 * HIVE_SERDE_SCAN_OVERHEAD_FACTOR;
--- End diff --
I am thinking this cost should include the number of columns as
well...suppose there are lots of columns(e.g 500), we want both types of plans
to be equally penalized.
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[GitHub] drill pull request: DRILL-3884: Fix lower parallelization issues w...
GitHub user vkorukanti opened a pull request: https://github.com/apache/drill/pull/185 DRILL-3884: Fix lower parallelization issues with Hive's native scan. @amansinha100 Could you please review the patch? You can merge this pull request into a Git repository by running: $ git pull https://github.com/vkorukanti/drill DRILL-3884 Alternatively you can review and apply these changes as the patch at: https://github.com/apache/drill/pull/185.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #185 commit cdd71f1f2aa224f65147e084d75eacbc4ff7285b Author: vkorukanti Date: 2015-10-01T22:15:12Z DRILL-3884: Fix lower parallelization issues with Hive's native scan. --- 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 infrastruct...@apache.org or file a JIRA ticket with INFRA. ---
