Alex Behm has uploaded a new patch set (#2). Change subject: IMPALA-5309: Adds TABLESAMPLE clause for HDFS table refs. ......................................................................
IMPALA-5309: Adds TABLESAMPLE clause for HDFS table refs. Syntax: <tableref> TABLESAMPLE SYSTEM(<number>) [REPEATABLE(<number>)] The first number specifies the percent of table bytes to sample. The second number specifies the random seed to use. The sampling is coarse-grained. Impala keeps randomly adding files to the sample until at least the desired percentage of file bytes have been reached. Examples: SELECT * FROM t TABLESAMPLE SYSTEM(10) SELECT * FROM t TABLESAMPLE SYSTEM(50) REPEATABLE(1234) Testing: - Added parser, analyser, planner, and end-to-end tests - Private core/hdfs run passed Change-Id: Ief112cfb1e4983c5d94c08696dc83da9ccf43f70 --- M fe/src/main/cup/sql-parser.cup M fe/src/main/java/org/apache/impala/analysis/BaseTableRef.java M fe/src/main/java/org/apache/impala/analysis/CollectionTableRef.java M fe/src/main/java/org/apache/impala/analysis/InlineViewRef.java M fe/src/main/java/org/apache/impala/analysis/SingularRowSrcTableRef.java M fe/src/main/java/org/apache/impala/analysis/TableRef.java A fe/src/main/java/org/apache/impala/analysis/TableSampleClause.java M fe/src/main/java/org/apache/impala/catalog/HdfsPartition.java M fe/src/main/java/org/apache/impala/catalog/HdfsTable.java M fe/src/main/java/org/apache/impala/planner/HdfsPartitionPruner.java M fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java M fe/src/main/java/org/apache/impala/planner/SingleNodePlanner.java M fe/src/main/jflex/sql-scanner.flex M fe/src/test/java/org/apache/impala/analysis/AnalyzeStmtsTest.java M fe/src/test/java/org/apache/impala/analysis/ParserTest.java M fe/src/test/java/org/apache/impala/analysis/ToSqlTest.java M fe/src/test/java/org/apache/impala/planner/PlannerTest.java A testdata/workloads/functional-planner/queries/PlannerTest/tablesample.test A tests/query_test/test_tablesample.py 19 files changed, 703 insertions(+), 63 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/68/6868/2 -- To view, visit http://gerrit.cloudera.org:8080/6868 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: newpatchset Gerrit-Change-Id: Ief112cfb1e4983c5d94c08696dc83da9ccf43f70 Gerrit-PatchSet: 2 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Alex Behm <alex.b...@cloudera.com> Gerrit-Reviewer: Alex Behm <alex.b...@cloudera.com> Gerrit-Reviewer: Marcel Kornacker <mar...@cloudera.com>
