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Posted to issues@drill.apache.org by "Aman Sinha (JIRA)" <ji...@apache.org> on 2015/03/22 17:09:10 UTC

[jira] [Commented] (DRILL-2157) Directory pruning on subdirectories only and data type conversions for directory filters

    [ https://issues.apache.org/jira/browse/DRILL-2157?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14375041#comment-14375041 ] 

Aman Sinha commented on DRILL-2157:
-----------------------------------

Most of the issues listed here have been fixed by DRILL-2353 and are available in the 0.8 release.  This includes filters that have range conditions (between, <, > etc.)  and filters on subdirectories without specifying parent directory.  I am not completely sure about the casting issue since I could not reproduce the original issue.   

I am marking this as fixed for 0.8.  [~aengelbrecht] could you please try the 0.8 release and verify ?  If there are remaining issues, pls open a new JIRA.  

> Directory pruning on subdirectories only and data type conversions for directory filters
> ----------------------------------------------------------------------------------------
>
>                 Key: DRILL-2157
>                 URL: https://issues.apache.org/jira/browse/DRILL-2157
>             Project: Apache Drill
>          Issue Type: Improvement
>          Components: Query Planning & Optimization
>    Affects Versions: Future
>            Reporter: Andries Engelbrecht
>            Assignee: Aman Sinha
>            Priority: Minor
>             Fix For: 0.8.0
>
>
> Drill will scan all files and directories when using only a subdirectory as a predicate. Additionally if the data type for the directory filter is not a string and is converted Drill will also first scan all the subdirectories adn files before applying the filter.
> My current observation is that for a directory structure as listed below,
> the pruning only works if the full tree is provided. If only a lower level
> directory is supplied in the filter condition Drill only uses it as a
> filter.
> With directory structure as below
> /2015
>         /01
>                /10
>                /11
>                /12
>                /13
>                /14
> Query:
> select count(id) from `/foo` t where dir0='2015' and dir1='01' and
> dir2='10'
> Produces the correct pruning and query plan
> 01-02            Project(id=[$3]): rowcount = 3670316.0, cumulative cost =
> {1.1010948E7 rows, 1.4681284E7 cpu, 0.0 io, 0.0 network, 0.0 memory}, id =
> 28434
> 01-03              Project(dir0=[$0], dir1=[$3], dir2=[$2], id=[$1]):
> rowcount = 3670316.0, cumulative cost = {7340632.0 rows, 1.468128E7 cpu,
> 0.0 io, 0.0 network, 0.0 memory}, id = 28433
> 01-04                Scan(groupscan=[EasyGroupScan [selectionRoot=/foo,
> numFiles=24, columns=[`dir0`, `dir1`, `dir2`, `id`]
> However:
> select count(id) from `/foo` t where dir2='10'
> Produces full scan of all sub directories and only applies a filter
> condition after the fact. Notice the numFiles between the 2, even though it
> lists columns in the base scan
> 01-04                Filter(condition=[=($0, '10')]): rowcount =
> 9423761.7, cumulative cost = {1.88475234E8 rows, 3.76950476E8 cpu, 0.0 io,
> 0.0 network, 0.0 memory}, id = 27470
> 01-05                  Project(dir2=[$1], id=[$0]): rowcount =
> 6.2825078E7, cumulative cost = {1.25650156E8 rows, 1.25650164E8 cpu, 0.0
> io, 0.0 network, 0.0 memory}, id = 27469
> 01-06                    Scan(groupscan=[EasyGroupScan
> [selectionRoot=/foo, numFiles=405, columns=[`dir2`, `id`]
> Also using the wrong data type for the filter produces a full scan
> select count(id) from `/foo` where dir_year=2015 and dir_month=01 and dir_day=14
> Produces
> 01-04                Filter(condition=[AND(=(CAST($1):ANY NOT NULL, 2015), =(CAST($2):ANY NOT NULL, 1), =(CAST($3):ANY NOT NULL, 10))]): rowcount = 212034.63825, cumulative cost = {1.88475234E8 rows, 1.005201264E9 cpu, 0.0 io, 0.0 network, 0.0 memory}, id = 34910
> 01-05                  Project(id=[$2], dir0=[$3], dir1=[$1], dir2=[$0]): rowcount = 6.2825078E7, cumulative cost = {1.25650156E8 rows, 2.51300328E8 cpu, 0.0 io, 0.0 network, 0.0 memory}, id = 34909
> 01-06                    Scan(groupscan=[EasyGroupScan [selectionRoot=/foo, numFiles=405, columns=[`id`, `dir0`, `dir1`, `dir2`],



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