Hello Dimitris Tsirogiannis,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/6840
to look at the new patch set (#8).
Change subject: IMPALA-2373: Extrapolate row counts for HDFS tables.
......................................................................
IMPALA-2373: Extrapolate row counts for HDFS tables.
The main idea of this patch is to use table stats to
extrapolate the row counts for new/modified partitions.
Existing behavior:
- Partitions that lack the row count stat are ignored
when estimating the cardinality of HDFS scans. Such
partitions effectively have an estimated row count
of zero.
- We always use the row count stats for partitions that
have one. The row count may be innaccurate if data in
such partitions has changed significantly.
Summary of changes:
- Enhance COMPUTE STATS to also store the total number
of file bytes in the table.
- Use the table-level row count and file bytes stats
to estimate the number of rows in a scan.
- A new impalad startup flag is added to enable/disable
the extrapolation behavior. The feature is disabled by
default. Note that even with the feature disabled,
COMPUTE STATS stores the file bytes so you can enable
the feature without having to COMPUTE STATS again.
Testing:
- Added new FE unit test
- Added new EE test
Change-Id: I972c8a03ed70211734631a7dc9085cb33622ebc4
---
M be/src/common/global-flags.cc
M be/src/exec/catalog-op-executor.cc
M be/src/util/backend-gflag-util.cc
M common/thrift/BackendGflags.thrift
M common/thrift/CatalogObjects.thrift
M common/thrift/JniCatalog.thrift
M fe/src/main/java/org/apache/impala/analysis/ComputeStatsStmt.java
M fe/src/main/java/org/apache/impala/catalog/DataSourceTable.java
M fe/src/main/java/org/apache/impala/catalog/HBaseTable.java
M fe/src/main/java/org/apache/impala/catalog/HdfsTable.java
M fe/src/main/java/org/apache/impala/catalog/KuduTable.java
M fe/src/main/java/org/apache/impala/catalog/Table.java
M fe/src/main/java/org/apache/impala/catalog/View.java
M fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java
M fe/src/main/java/org/apache/impala/planner/ScanNode.java
M fe/src/main/java/org/apache/impala/service/BackendConfig.java
M fe/src/main/java/org/apache/impala/service/CatalogOpExecutor.java
M fe/src/test/java/org/apache/impala/catalog/CatalogObjectToFromThriftTest.java
A fe/src/test/java/org/apache/impala/planner/StatsExtrapolationTest.java
M
testdata/workloads/functional-planner/queries/PlannerTest/constant-folding.test
M
testdata/workloads/functional-planner/queries/PlannerTest/mt-dop-validation.test
M
testdata/workloads/functional-planner/queries/PlannerTest/parquet-filtering.test
M
testdata/workloads/functional-planner/queries/PlannerTest/resource-requirements.test
M
testdata/workloads/functional-planner/queries/PlannerTest/sort-expr-materialization.test
A testdata/workloads/functional-query/queries/QueryTest/stats-extrapolation.test
A tests/custom_cluster/test_stats_extrapolation.py
M tests/metadata/test_explain.py
27 files changed, 770 insertions(+), 180 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/40/6840/8
--
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I972c8a03ed70211734631a7dc9085cb33622ebc4
Gerrit-PatchSet: 8
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Alex Behm <[email protected]>
Gerrit-Reviewer: Alex Behm <[email protected]>
Gerrit-Reviewer: Dimitris Tsirogiannis <[email protected]>
Gerrit-Reviewer: Marcel Kornacker <[email protected]>
Gerrit-Reviewer: Mostafa Mokhtar <[email protected]>
