]
Steven Hawkins commented on TEIID-2902:
---------------------------------------
My first thought was to use the SortUtility singlePassSort logic and merge in subsets, but
that will require additional work as even the single pass currently reads all results
prior to returning the sorted sublists. We need it to be iterative in this scenario.
More incremental join when a limit is present
---------------------------------------------
Key: TEIID-2902
URL:
https://issues.jboss.org/browse/TEIID-2902
Project: Teiid
Issue Type: Enhancement
Components: Query Engine
Affects Versions: 8.7
Reporter: Ivan Chan
Assignee: Steven Hawkins
Fix For: 8.8
For SQL like:
SELECT
t1.column1,
t2.column1
FROM
schema1.table1 t1,
schema2.table1 t2
WHERE
t1.column2=t2.column2
LIMIT 100
Teiid may get the whole schema1.table1 content and the whole schema2.table1 content, do
the join in memory and then, limit the resultset to 100 records.
However, I think teiid can fetch smaller set of data then do a join. If the join result
set is less than number of rows asking, keep fetching next set of data and do a join
until hits the limit number.