[
https://issues.apache.org/jira/browse/CALCITE-4333?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17248015#comment-17248015
]
Ruben Q L edited comment on CALCITE-4333 at 12/11/20, 4:30 PM:
---------------------------------------------------------------
[~danny0405] unfortunately, the proposed fix is insufficient, as soon as the
LogicalSort is not at the top of the plan (e.g. it is the input of a final
LogicalProject), it is not decorrelated (and it could/should be).
Example:
{code}
@Test void testSortLimitWithCorrelateInput2() {
final String sql = ""
+ "SELECT ename||deptno FROM\n"
+ "(SELECT deptno, ename\n"
+ " FROM\n"
+ " (SELECT DISTINCT deptno FROM emp) t1,\n"
+ " LATERAL (\n"
+ " SELECT ename, sal\n"
+ " FROM emp\n"
+ " WHERE deptno = t1.deptno)\n"
+ " ORDER BY ename DESC\n"
+ " LIMIT 3)";
sql(sql).ok();
}
{code}
Expected:
{noformat}
LogicalProject(EXPR$0=[||($1, CAST($0):VARCHAR NOT NULL)])
LogicalSort(sort0=[$1], dir0=[DESC], fetch=[3])
LogicalProject(DEPTNO=[$0], ENAME=[$1])
LogicalJoin(condition=[=($0, $3)], joinType=[inner])
LogicalAggregate(group=[{0}])
LogicalProject(DEPTNO=[$7])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
LogicalProject(ENAME=[$1], SAL=[$5], DEPTNO=[$7])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
{noformat}
But it is:
{noformat}
LogicalProject(EXPR$0=[||($1, CAST($0):VARCHAR NOT NULL)])
LogicalSort(sort0=[$1], dir0=[DESC], fetch=[3])
LogicalProject(DEPTNO=[$0], ENAME=[$1])
LogicalCorrelate(correlation=[$cor0], joinType=[inner],
requiredColumns=[{0}])
LogicalAggregate(group=[{0}])
LogicalProject(DEPTNO=[$7])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
LogicalProject(ENAME=[$1], SAL=[$5])
LogicalFilter(condition=[=($7, $cor0.DEPTNO)])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
{noformat}
was (Author: rubenql):
[~danny0405] unfortunately, the proposed fix is insufficient, as soon as the
LogicalSort is not at the top of the plan (e.g. it is the input of a final
LogicalProject), it is not decorrelated.
Example:
{code}
@Test void testSortLimitWithCorrelateInput2() {
final String sql = ""
+ "SELECT ename||deptno FROM\n"
+ "(SELECT deptno, ename\n"
+ " FROM\n"
+ " (SELECT DISTINCT deptno FROM emp) t1,\n"
+ " LATERAL (\n"
+ " SELECT ename, sal\n"
+ " FROM emp\n"
+ " WHERE deptno = t1.deptno)\n"
+ " ORDER BY ename DESC\n"
+ " LIMIT 3)";
sql(sql).ok();
}
{code}
Expected:
{noformat}
LogicalProject(EXPR$0=[||($1, CAST($0):VARCHAR NOT NULL)])
LogicalSort(sort0=[$1], dir0=[DESC], fetch=[3])
LogicalProject(DEPTNO=[$0], ENAME=[$1])
LogicalJoin(condition=[=($0, $3)], joinType=[inner])
LogicalAggregate(group=[{0}])
LogicalProject(DEPTNO=[$7])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
LogicalProject(ENAME=[$1], SAL=[$5], DEPTNO=[$7])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
{noformat}
But it is:
{noformat}
LogicalProject(EXPR$0=[||($1, CAST($0):VARCHAR NOT NULL)])
LogicalSort(sort0=[$1], dir0=[DESC], fetch=[3])
LogicalProject(DEPTNO=[$0], ENAME=[$1])
LogicalCorrelate(correlation=[$cor0], joinType=[inner],
requiredColumns=[{0}])
LogicalAggregate(group=[{0}])
LogicalProject(DEPTNO=[$7])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
LogicalProject(ENAME=[$1], SAL=[$5])
LogicalFilter(condition=[=($7, $cor0.DEPTNO)])
LogicalTableScan(table=[[CATALOG, SALES, EMP]])
{noformat}
> The Sort rel should be decorrelated even though it has fetch or limit when
> its parent is not a Correlate
> --------------------------------------------------------------------------------------------------------
>
> Key: CALCITE-4333
> URL: https://issues.apache.org/jira/browse/CALCITE-4333
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.26.0
> Reporter: Danny Chen
> Assignee: Danny Chen
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.27.0
>
> Time Spent: 1h 10m
> Remaining Estimate: 0h
>
> Check this test in SqlToRelConverterTest:
> {code:java}
> @Test void testSortLimitWithCorrelateInput() {
> final String sql = "" +
> "SELECT deptno, ename\n" +
> " FROM\n" +
> " (SELECT DISTINCT deptno FROM emp) t1,\n" +
> " LATERAL (\n" +
> " SELECT ename, sal\n" +
> " FROM emp\n" +
> " WHERE deptno = t1.deptno)\n" +
> " ORDER BY ename DESC\n" +
> " LIMIT 3";
> sql(sql).ok();
> }
> {code}
> The current plan is:
> {code:xml}
> LogicalSort(sort0=[$1], dir0=[DESC], fetch=[3])
> LogicalProject(DEPTNO=[$0], ENAME=[$1])
> LogicalCorrelate(correlation=[$cor0], joinType=[inner],
> requiredColumns=[{0}])
> LogicalAggregate(group=[{0}])
> LogicalProject(DEPTNO=[$7])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> LogicalProject(ENAME=[$1], SAL=[$5])
> LogicalFilter(condition=[=($7, $cor0.DEPTNO)])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> {code}
> It actually can be decorrelated to:
> {code:xml}
> LogicalSort(sort0=[$1], dir0=[DESC], fetch=[3])
> LogicalProject(DEPTNO=[$0], ENAME=[$1])
> LogicalJoin(condition=[=($0, $3)], joinType=[inner])
> LogicalAggregate(group=[{0}])
> LogicalProject(DEPTNO=[$7])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> LogicalProject(ENAME=[$1], SAL=[$5], DEPTNO=[$7])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]])
> {code}
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
