Andrey Mashenkov created IGNITE-28296:
-----------------------------------------
Summary: SQL. Prefer table scan for unbounded scan with no sort
required.
Key: IGNITE-28296
URL: https://issues.apache.org/jira/browse/IGNITE-28296
Project: Ignite
Issue Type: Improvement
Components: sql ai3
Reporter: Andrey Mashenkov
Assume there is a table with secondary index by some column.
In the next queries, `val1` is non-indexed column.
{noformat}
SELECT * FROM T1 LEFT JOIN T2 ON t1.val1 = t2.val1
SELECT * FROM T1 ORDER BY val1
SELECT * FROM T1{noformat}
As for now, we choose index scan if table size is zero.
So, we choose more expensive plan with IndexScan, when statistics are not
available yet.
The reason is we can got zero cost if IndexScan has no condition.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
