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Posted to issues@tajo.apache.org by "Jihoon Son (JIRA)" <ji...@apache.org> on 2015/05/13 08:07:59 UTC
[jira] [Created] (TAJO-1600) Invalid query planning for distinct
group-by
Jihoon Son created TAJO-1600:
--------------------------------
Summary: Invalid query planning for distinct group-by
Key: TAJO-1600
URL: https://issues.apache.org/jira/browse/TAJO-1600
Project: Tajo
Issue Type: Bug
Components: planner/optimizer
Reporter: Jihoon Son
Fix For: 0.11.0
For a query involving distinct operator, group-by is always executed at the last step of the query. Let me consider an example query as follows.
{noformat}
default> select distinct a.col3 from test as a left outer join lineitem b on a.col1 = b.l_orderkey order by a.col3;
{noformat}
The plan for this query is
{noformat}
GROUP_BY(5)(col3)
=> target list: default.a.col3 (TEXT)
=> out schema:{(1) default.a.col3 (TEXT)}
=> in schema:{(1) default.a.col3 (TEXT)}
SORT(3)
=> Sort Keys: default.a.col3 (TEXT) (asc)
JOIN(7)(LEFT_OUTER)
=> Join Cond: default.a.col1 (INT4) = default.b.l_orderkey (INT4)
=> target list: default.a.col3 (TEXT)
=> out schema: {(1) default.a.col3 (TEXT)}
=> in schema: {(3) default.a.col3 (TEXT), default.a.col1 (INT4), default.b.l_orderkey (INT4)}
SCAN(1) on default.lineitem_large as b
=> target list: default.b.l_orderkey (INT4)
=> out schema: {(1) default.b.l_orderkey (INT4)}
=> in schema: {(16) default.b.l_orderkey (INT4), default.b.l_partkey (INT4), default.b.l_suppkey (INT4), default.b.l_linenumber (INT4), default.b.l_quantity (FLOAT8), default.b.l_extendedprice (FLOAT8), default.b.l_discount (FLOAT8), default.b.l_tax (FLOAT8), default.b.l_returnflag (TEXT), default.b.l_linestatus (TEXT), default.b.l_shipdate (TEXT), default.b.l_commitdate (TEXT), default.b.l_receiptdate (TEXT), default.b.l_shipinstruct (TEXT), default.b.l_shipmode (TEXT), default.b.l_comment (TEXT)}
PARTITIONS_SCAN(8) on default.testbroadcastmulticolumnpartitiontable as a
=> target list: default.a.col3 (TEXT), default.a.col1 (INT4)
=> num of filtered paths: 3
=> out schema: {(2) default.a.col3 (TEXT), default.a.col1 (INT4)}
=> in schema: {(2) default.a.col1 (INT4), default.a.col2 (FLOAT4)}
=> 0: hdfs://localhost:52705/tajo/warehouse/default/testbroadcastmulticolumnpartitiontable/col3=01/col4=1996
=> 1: hdfs://localhost:52705/tajo/warehouse/default/testbroadcastmulticolumnpartitiontable/col3=10/col4=1993
=> 2: hdfs://localhost:52705/tajo/warehouse/default/testbroadcastmulticolumnpartitiontable/col3=12/col4=1996
{noformat}
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