[jira] [Commented] (TRAFODION-1423) Indexes on trafodion should be created in aligned row format by default

[ASF GitHub Bot (JIRA)]

    [ 
https://issues.apache.org/jira/browse/TRAFODION-1423?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14651878#comment-14651878
 ] 

ASF GitHub Bot commented on TRAFODION-1423:
-------------------------------------------

Github user sureshsubbiah commented on a diff in the pull request:

    https://github.com/apache/incubator-trafodion/pull/37#discussion_r36086954
  
    --- Diff: core/sql/generator/GenRelScan.cpp ---
    @@ -2203,10 +2203,46 @@ short HbaseAccess::codeGen(Generator * generator)
                       ExpTupleDesc::SQLMX_KEY_FORMAT);
     
       const ValueIdList &retColumnList = retColRefSet_; 
    +  // Always get the index name -- it will be the base tablename for
    +  // primary access if it is trafodion table.
    +  char * tablename = NULL;
    +  char * snapshotName = NULL;
    +  LatestSnpSupportEnum  latestSnpSupport=  latest_snp_supported;
    +  if ((getTableDesc()->getNATable()->isHbaseRowTable()) ||
    +      (getTableDesc()->getNATable()->isHbaseCellTable()))
    +    {
    +      tablename =
    +        space->AllocateAndCopyToAlignedSpace(
    +                                             
GenGetQualifiedName(getTableName().getQualifiedNameObj().getObjectName()), 0);
    +      latestSnpSupport = latest_snp_not_trafodion_table;
    +    }
    +  else
    +    {
    +      if (getIndexDesc() && getIndexDesc()->getNAFileSet())
    +      {
    +         tablename = 
space->AllocateAndCopyToAlignedSpace(GenGetQualifiedName(getIndexDesc()->getNAFileSet()->getFileSetName()),
 0);
    +         if (getIndexDesc()->isClusteringIndex())
    +         {
    +            //base table
    +            snapshotName = 
(char*)getTableDesc()->getNATable()->getSnapshotName() ;
    +           if (snapshotName == NULL)
    +             latestSnpSupport = latest_snp_no_snapshot_available;
    +          }
    +          else
    +            latestSnpSupport = latest_snp_index_table;
    --- End diff --
    
    Do we support the case where the base table has no snapshot defined on it 
but an index on the table does have a snapshot?


> Indexes on trafodion should be created in aligned row format by default
> -----------------------------------------------------------------------
>
>                 Key: TRAFODION-1423
>                 URL: https://issues.apache.org/jira/browse/TRAFODION-1423
>             Project: Apache Trafodion
>          Issue Type: Improvement
>          Components: sql-cmp, sql-cmu
>    Affects Versions: 2.0-incubating
>            Reporter: Selvaganesan Govindarajan
>            Assignee: Selvaganesan Govindarajan
>
> Currently indexes are created with the same row format as the table. However, 
> indexes can be created in aligned row format independent of the table because 
> the columns in the index table doesn't have any other column other than salt, 
> index columns, and primary key of the table. These column values constitute 
> the rowid. Index rows are always deleted and inserted and are never updated. 
> Hence, it goes well to create index in aligned row format. In addition, index 
> in aligned row format has the following advantages:
> - Reduced storage space for the index
> - Reduced block cache and memstore space at runtime



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