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Posted to issues@calcite.apache.org by "Hanumath Rao Maduri (JIRA)" <ji...@apache.org> on 2019/01/28 18:59:00 UTC

[jira] [Created] (CALCITE-2813) Semijoins are not being considered in LoptOptimizeJoinRule for ordering the joins

Hanumath Rao Maduri created CALCITE-2813:
--------------------------------------------

             Summary: Semijoins are not being considered in LoptOptimizeJoinRule for ordering the joins
                 Key: CALCITE-2813
                 URL: https://issues.apache.org/jira/browse/CALCITE-2813
             Project: Calcite
          Issue Type: Bug
          Components: core
    Affects Versions: 1.17.0
            Reporter: Hanumath Rao Maduri
            Assignee: Julian Hyde


During the debugging a performance issue in Apache Drill, I have noticed that the semi joins are not being considered in LoptOptimizeJoinRule. Due to this sub-optimal join ordering is resulting for some of the Drill queries. 

Here is an example for the same.
: jdbc:drill:zk=local> alter session set `planner.enable_semijoin` = true;
+-------+-----------------------------------+
|  ok   |              summary              |
+-------+-----------------------------------+
| true  | planner.enable_semijoin updated.  |
+-------+-----------------------------------+
1 row selected (0.073 seconds)
0: jdbc:drill:zk=local> explain plan without implementation for select * from dfs.`/home/mapr/data/sf1/parquet/web_sales` ws1, dfs.`/home/mapr/data/sf1/parquet/web_sales` ws2  where ws1.ws_ship_date_sk in (select dd.d_date_sk from dfs.`/home/mapr/data/sf1/parquet/date_dim` dd) and ws1.ws_order_number = ws2.ws_order_number;
+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
|                                       text                                       |                                       json                                       |
+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
| DrillScreenRel
  DrillProjectRel(**=[$0], **0=[$3])
    DrillSemiJoinRel(condition=[=($1, $6)], joinType=[inner])
      DrillJoinRel(condition=[=($2, $5)], joinType=[inner])
        DrillScanRel(table=[[dfs, /home/mapr/data/sf1/parquet/web_sales]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=file:/home/mapr/data/sf1/parquet/web_sales]], selectionRoot=file:/home/mapr/data/sf1/parquet/web_sales, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`**`, `ws_ship_date_sk`, `ws_order_number`]]])
        DrillScanRel(table=[[dfs, /home/mapr/data/sf1/parquet/web_sales]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=file:/home/mapr/data/sf1/parquet/web_sales]], selectionRoot=file:/home/mapr/data/sf1/parquet/web_sales, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`**`, `ws_ship_date_sk`, `ws_order_number`]]])
      DrillScanRel(table=[[dfs, /home/mapr/data/sf1/parquet/date_dim]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=file:/home/mapr/data/sf1/parquet/date_dim]], selectionRoot=file:/home/mapr/data/sf1/parquet/date_dim, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`d_date_sk`]]])

0: jdbc:drill:zk=local> alter session set `planner.enable_semijoin` = false;
+-------+-----------------------------------+
|  ok   |              summary              |
+-------+-----------------------------------+
| true  | planner.enable_semijoin updated.  |
+-------+-----------------------------------+
1 row selected (0.077 seconds)
0: jdbc:drill:zk=local> explain plan without implementation for select * from dfs.`/home/mapr/data/sf1/parquet/web_sales` ws1, dfs.`/home/mapr/data/sf1/parquet/web_sales` ws2  where ws1.ws_ship_date_sk in (select dd.d_date_sk from dfs.`/home/mapr/data/sf1/parquet/date_dim` dd) and ws1.ws_order_number = ws2.ws_order_number;
+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
|                                       text                                       |                                       json                                       |
+----------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
| DrillScreenRel
  DrillProjectRel(**=[$0], **0=[$3])
    DrillProjectRel(**=[$0], ws_ship_date_sk=[$1], ws_order_number=[$2], **0=[$4], ws_ship_date_sk0=[$5], ws_order_number0=[$6], d_date_sk=[$3])
      DrillJoinRel(condition=[=($2, $6)], joinType=[inner])
        DrillJoinRel(condition=[=($1, $3)], joinType=[inner])
          DrillScanRel(table=[[dfs, /home/mapr/data/sf1/parquet/web_sales]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=file:/home/mapr/data/sf1/parquet/web_sales]], selectionRoot=file:/home/mapr/data/sf1/parquet/web_sales, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`**`, `ws_ship_date_sk`, `ws_order_number`]]])
          DrillAggregateRel(group=[\{0}])
            DrillScanRel(table=[[dfs, /home/mapr/data/sf1/parquet/date_dim]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=file:/home/mapr/data/sf1/parquet/date_dim]], selectionRoot=file:/home/mapr/data/sf1/parquet/date_dim, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`d_date_sk`]]])
        DrillScanRel(table=[[dfs, /home/mapr/data/sf1/parquet/web_sales]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=file:/home/mapr/data/sf1/parquet/web_sales]], selectionRoot=file:/home/mapr/data/sf1/parquet/web_sales, numFiles=1, numRowGroups=1, usedMetadataFile=false, columns=[`**`, `ws_ship_date_sk`, `ws_order_number`]]])



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