You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@drill.apache.org by "Khurram Faraaz (JIRA)" <ji...@apache.org> on 2015/10/08 20:22:26 UTC
[jira] [Updated] (DRILL-3419) Handle scans optimally when all files
are pruned out
[ https://issues.apache.org/jira/browse/DRILL-3419?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Khurram Faraaz updated DRILL-3419:
----------------------------------
Assignee: Jinfeng Ni
> Handle scans optimally when all files are pruned out
> ----------------------------------------------------
>
> Key: DRILL-3419
> URL: https://issues.apache.org/jira/browse/DRILL-3419
> Project: Apache Drill
> Issue Type: Bug
> Components: Query Planning & Optimization
> Affects Versions: 1.1.0
> Reporter: Khurram Faraaz
> Assignee: Jinfeng Ni
> Fix For: 1.3.0
>
>
> Note that in case (1) and case (2) we prune, however it is not clear if we prune is case (3), that is because we see a FILTER in the query plan in case (3)
> CTAS
> {code}
> 0: jdbc:drill:schema=dfs.tmp> CREATE TABLE CTAS_ONE_MILN_RWS_PER_GROUP(col1, col2) PARTITION BY (col2) AS select cast(columns[0] as bigint) col1, cast(columns[1] as char(2)) col2 from `millionValGroup.csv`;
> +-----------+----------------------------+
> | Fragment | Number of records written |
> +-----------+----------------------------+
> | 1_1 | 21932064 |
> | 1_0 | 28067936 |
> +-----------+----------------------------+
> 2 rows selected (73.661 seconds)
> {code}
> case 1)
> {code}
> explain plan for select col1, col2 from CTAS_ONE_MILN_RWS_PER_GROUP where col2 LIKE '%Z%';
> | 00-00 Screen
> 00-01 Project(col1=[$0], col2=[$1])
> 00-02 UnionExchange
> 01-01 Scan(groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_0_3.parquet], ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_1_3.parquet]], selectionRoot=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP, numFiles=2, columns=[`col2`, `col1`]]])
> {code}
> case 2)
> {code}
> explain plan for select col1, col2 from CTAS_ONE_MILN_RWS_PER_GROUP where col2 LIKE 'A%';
> | 00-00 Screen
> 00-01 Project(col1=[$0], col2=[$1])
> 00-02 UnionExchange
> 01-01 Scan(groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_0_3.parquet], ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_0_2.parquet], ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_1_1.parquet], ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_1_2.parquet], ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_1_3.parquet], ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_0_1.parquet]], selectionRoot=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP, numFiles=6, columns=[`col2`, `col1`]]])
> {code}
> case 3) we are NOT pruning here.
> {code}
> explain plan for select col1, col2 from CTAS_ONE_MILN_RWS_PER_GROUP where col2 LIKE 'Z%';
> | 00-00 Screen
> 00-01 Project(col1=[$1], col2=[$0])
> 00-02 SelectionVectorRemover
> 00-03 Filter(condition=[LIKE($0, 'Z%')])
> 00-04 Project(col2=[$1], col1=[$0])
> 00-05 Scan(groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP/1_1_48.parquet]], selectionRoot=/tmp/CTAS_ONE_MILN_RWS_PER_GROUP, numFiles=1, columns=[`col2`, `col1`]]])
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)