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Khurram Faraaz commented on DRILL-4735: --------------------------------------- [~cch...@maprtech.com] re-assigned Jinfeng as reviewer, I will own this from test and add tests and mark it as closed once tests are reviewed and merged. Thanks. > Count(dir0) on parquet returns 0 result > --------------------------------------- > > Key: DRILL-4735 > URL: https://issues.apache.org/jira/browse/DRILL-4735 > Project: Apache Drill > Issue Type: Bug > Components: Query Planning & Optimization, Storage - Parquet > Affects Versions: 1.0.0, 1.4.0, 1.6.0, 1.7.0 > Reporter: Krystal > Assignee: Arina Ielchiieva > Priority: Critical > Labels: ready-to-commit > Fix For: 1.12.0 > > > Selecting a count of dir0, dir1, etc against a parquet directory returns 0 > rows. > select count(dir0) from `min_max_dir`; > +---------+ > | EXPR$0 | > +---------+ > | 0 | > +---------+ > select count(dir1) from `min_max_dir`; > +---------+ > | EXPR$0 | > +---------+ > | 0 | > +---------+ > If I put both dir0 and dir1 in the same select, it returns expected result: > select count(dir0), count(dir1) from `min_max_dir`; > +---------+---------+ > | EXPR$0 | EXPR$1 | > +---------+---------+ > | 600 | 600 | > +---------+---------+ > Here is the physical plan for count(dir0) query: > {code} > 00-00 Screen : rowType = RecordType(BIGINT EXPR$0): rowcount = 20.0, > cumulative cost = {22.0 rows, 22.0 cpu, 0.0 io, 0.0 network, 0.0 memory}, id > = 1346 > 00-01 Project(EXPR$0=[$0]) : rowType = RecordType(BIGINT EXPR$0): > rowcount = 20.0, cumulative cost = {20.0 rows, 20.0 cpu, 0.0 io, 0.0 network, > 0.0 memory}, id = 1345 > 00-02 Project(EXPR$0=[$0]) : rowType = RecordType(BIGINT EXPR$0): > rowcount = 20.0, cumulative cost = {20.0 rows, 20.0 cpu, 0.0 io, 0.0 network, > 0.0 memory}, id = 1344 > 00-03 > Scan(groupscan=[org.apache.drill.exec.store.pojo.PojoRecordReader@3da85d3b[columns > = null, isStarQuery = false, isSkipQuery = false]]) : rowType = > RecordType(BIGINT count): rowcount = 20.0, cumulative cost = {20.0 rows, 20.0 > cpu, 0.0 io, 0.0 network, 0.0 memory}, id = 1343 > {code} > Here is part of the explain plan for the count(dir0) and count(dir1) in the > same select: > {code} > 00-00 Screen : rowType = RecordType(BIGINT EXPR$0, BIGINT EXPR$1): > rowcount = 60.0, cumulative cost = {1206.0 rows, 15606.0 cpu, 0.0 io, 0.0 > network, 0.0 memory}, id = 1623 > 00-01 Project(EXPR$0=[$0], EXPR$1=[$1]) : rowType = RecordType(BIGINT > EXPR$0, BIGINT EXPR$1): rowcount = 60.0, cumulative cost = {1200.0 rows, > 15600.0 cpu, 0.0 io, 0.0 network, 0.0 memory}, id = 1622 > 00-02 StreamAgg(group=[{}], EXPR$0=[COUNT($0)], EXPR$1=[COUNT($1)]) : > rowType = RecordType(BIGINT EXPR$0, BIGINT EXPR$1): rowcount = 60.0, > cumulative cost = {1200.0 rows, 15600.0 cpu, 0.0 io, 0.0 network, 0.0 > memory}, id = 1621 > 00-03 Scan(groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath > [path=maprfs:/drill/testdata/min_max_dir/1999/Apr/voter20.parquet/0_0_0.parquet], > ReadEntryWithPath > [path=maprfs:/drill/testdata/min_max_dir/1999/MAR/voter15.parquet/0_0_0.parquet], > ReadEntryWithPath > [path=maprfs:/drill/testdata/min_max_dir/1985/jan/voter5.parquet/0_0_0.parquet], > ReadEntryWithPath > [path=maprfs:/drill/testdata/min_max_dir/1985/apr/voter60.parquet/0_0_0.parquet],..., > ReadEntryWithPath > [path=maprfs:/drill/testdata/min_max_dir/2014/jul/voter35.parquet/0_0_0.parquet]], > selectionRoot=maprfs:/drill/testdata/min_max_dir, numFiles=16, > usedMetadataFile=false, columns=[`dir0`, `dir1`]]]) : rowType = > RecordType(ANY dir0, ANY dir1): rowcount = 600.0, cumulative cost = {600.0 > rows, 1200.0 cpu, 0.0 io, 0.0 network, 0.0 memory}, id = 1620 > {code} > Notice that in the first case, > "org.apache.drill.exec.store.pojo.PojoRecordReader" is used. -- This message was sent by Atlassian JIRA (v6.4.14#64029)