I've observed in my
no-sql adapter
implementation that for q
ueries with
P
roject
+
S
ort by
ONE
column
t
he
Project
is pushed (as expected)
before the Sort but for Sort
on MULTIPLE
columns
the Sort is before the Project.
For example
for a query with one
sort column:
SELECT yearPublished FROM BookMaster ORDER BY yearPublished ASC
The plan looks like expected (project before the sort)
PLAN=GeodeToEnumerableConverterRel
*GeodeSortRel*(sort0=[$0], dir0=[ASC])
GeodeProjectRel(yearPublished=[$2])
GeodeTableScanRel(table=[[TEST, BookMaster]])
But
for sort
with
two
columns:
SELECT yearPublished, itemNumber from BookMaster ORDER BY yearPublished
ASC, itemNumber ASC
The
the plan is:
PLAN=GeodeToEnumerableConverterRel
GeodeProjectRel(yearPublished=[$2], itemNumber=[$0])
*GeodeSortRel*(sort0=[$2], sort1=[$0], dir0=[ASC], dir1=[ASC])
GeodeTableScanRel(table=[[TEST, BookMaster]])
I'm not sure i can explain
why in the second case the Sort appears before the Project?
Here
are my cost functions:
*
GeodeSortRel
:
https://github.com/tzolov/calcite/blob/geode-1.3/geode/src/main/java/org/apache/calcite/adapter/geode/rel/GeodeSortRel.java#L51
* GoedeProjectRel:
https://github.com/tzolov/calcite/blob/4a631d9055340f64f5e644454551f964ea08f9de/geode/src/main/java/org/apache/calcite/adapter/geode/rel/GeodeProjectRel.java#L52
Cheers,
Christian
