[
https://issues.apache.org/jira/browse/CALCITE-606?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14359400#comment-14359400
]
Jinfeng Ni commented on CALCITE-606:
------------------------------------
Re 2. In the testcase, collations are supposedly to kick in when logical SCAN
is converted into physical SCAN. collations are not know in logical SCAN phase.
{code}
Line :299
call.transformTo(new PhysTable(rel.getCluster()));
Line 383
public PhysTable(RelOptCluster cluster) {
super(cluster, cluster.traitSet().replace(PHYSICAL).replace(COLLATION));
{code}
I think the assumption of knowing traits only in physical stage makes senses :
in logical plan, we have
{code}
Aggregate
\
PROJECT
\
SCAN
{code}
We know the collation of SCAN only In physical stage. If the table has the
required collation, no SORT is required. If no collation exists, Calcite either
generates a plan by inserting SORT and do a SORT-based aggregation, or
generates a plan which uses hash-based aggregation. In that way, the logical
aggregate could be converted into SORT-based AGG or hash-based AGG, depending
on the collation of SCAN known in physical stage.
PS. I also have getStatistics, and use unwrap(). The only change I made is to
provide an empty collation list to logical SCAN.
{code}
@Override public Statistic getStatistic() {
return Statistics.of(100d, ImmutableList.<ImmutableBitSet>of(),
ImmutableList.<RelCollation>of()); // empty collation list for
logical SCAN.
// ImmutableList.of(COLLATION));
{code}
> Fix Trait Propagation and add test case
> ---------------------------------------
>
> Key: CALCITE-606
> URL: https://issues.apache.org/jira/browse/CALCITE-606
> Project: Calcite
> Issue Type: Bug
> Reporter: Jacques Nadeau
> Assignee: Jacques Nadeau
> Fix For: next
>
>
> Per my email to the dev list, it seems like we need to have a Trait
> propagation test case. Some things also seem broken. Dev list email:
> http://mail-archives.apache.org/mod_mbox/incubator-calcite-dev/201503.mbox/browser
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
