wangsheng has uploaded this change for review. ( http://gerrit.cloudera.org:8080/18829
Change subject: IMPALA-7942 (part 1): Add query hints for table cardinalities ...................................................................... IMPALA-7942 (part 1): Add query hints for table cardinalities Currently, We need execute 'COMPUTE STATS' manually to compute table stats info. Stats is very useful for query plan generate. Without these stats, query plan maybe worse. In order to solve this probelm, this patch adds a new query hint: 'TABLE_NUM_ROWS', we can use this hint to set table rows, even without table stats info. We can use this new hint after a hdfs or kudu table in query like this: * select col from t /* +TABLE_NUM_ROWS(1000) */; If set, Impala will use this value as table scanned rows, even if table has no stats. Testing: - Added new fe test in 'PlannerTest' - Added new fe test in 'AnalyzeStmtsTest' for negative cases Change-Id: I9f0c773f4e67782a1428db64062f68afbd257af7 --- M fe/src/main/java/org/apache/impala/analysis/TableRef.java M fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java M fe/src/main/java/org/apache/impala/planner/KuduScanNode.java M fe/src/main/java/org/apache/impala/planner/ScanNode.java M fe/src/main/java/org/apache/impala/planner/SingleNodePlanner.java M fe/src/test/java/org/apache/impala/analysis/AnalyzeStmtsTest.java M fe/src/test/java/org/apache/impala/planner/PlannerTest.java A testdata/workloads/functional-planner/queries/PlannerTest/table-cardinality-hint.test 8 files changed, 134 insertions(+), 10 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/29/18829/1 -- To view, visit http://gerrit.cloudera.org:8080/18829 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: I9f0c773f4e67782a1428db64062f68afbd257af7 Gerrit-Change-Number: 18829 Gerrit-PatchSet: 1 Gerrit-Owner: wangsheng <[email protected]>
