[
https://issues.apache.org/jira/browse/CALCITE-7616?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
leishp updated CALCITE-7616:
----------------------------
Description:
When a JDBC schema's dialect supports window functions (e.g. MySQL,
PostgreSQL), a query with CTE and RANK() throws AssertionError during
VolcanoPlanner optimization:
{code}
AssertionError: Relational expression
LogicalWindow.JDBC.TEST.[]
has calling-convention JDBC.TEST but does not implement the required interface
'interface org.apache.calcite.adapter.jdbc.JdbcRel' of that convention
{code}
h3. Reproduction
A JDBC schema with MySQL dialect ({{supportsWindowFunctions() = true}}), and a
query with CTE + RANK():
{code:sql}
WITH ranked AS (
SELECT customer_name, contract_amount,
RANK() OVER (ORDER BY contract_amount DESC) AS rnk
FROM sales_data
)
SELECT customer_name FROM ranked WHERE rnk <= 3
{code}
h3. Root cause
{{ProjectToLogicalProjectAndWindowRule}} passes the parent {{Project}}'s
traitSet directly to {{LogicalWindow.create()}} via {{CalcRelSplitter}}. When
the parent is a {{JdbcProject}} (JDBC convention), the generated
{{LogicalWindow}} inherits the JDBC convention but does not implement the
{{JdbcRel}} interface, causing an AssertionError in
{{VolcanoPlanner.registerImpl}}.
{code:java}
// ProjectToWindowRule.java:161 — passes project.getTraitSet() directly
final LogicalCalc calc =
new LogicalCalc(project.getCluster(), project.getTraitSet(), // JDBC
convention leaks in
project.getHints(), input, program);
{code}
This is related to CALCITE-3352 (wrong collation on generated Window) — both
bugs share the same root cause: {{ProjectToWindowRule}} blindly propagates the
parent's traitSet to the generated {{LogicalWindow}}. Danny Chen commented on
CALCITE-3352:
{quote}
We should limit this rule to only match logical nodes because it is a plan
rewrite.
{quote}
h3. Fix
Force {{Convention.NONE}} when creating the temporary {{LogicalCalc}}, so that
{{LogicalWindow}} never inherits a non-NONE convention:
{code:java}
// ProjectToWindowRule.java
final RelTraitSet traitSet =
project.getCluster().traitSetOf(Convention.NONE); // force Convention.NONE
final LogicalCalc calc =
new LogicalCalc(project.getCluster(), traitSet,
project.getHints(), input, program);
{code}
h3. Impact
- When dialect supports window functions: window function is pushed down to
database via {{JdbcProject}}. Correct behavior.
- When dialect does NOT support window functions:
{{ProjectToLogicalProjectAndWindowRule}} fires on {{LogicalProject(NONE)}} as
before. No change.
- No existing tests broken (verified {{RelOptRulesTest}} 902/902 passed).
h3. Scope
This is a targeted fix for the convention issue only. The collation issue
(CALCITE-3352) is tracked separately.
h3. Test
A JUnit test {{JdbcWindowConventionTest}} is provided in the PR, using HSQLDB
in-memory database with MySQL dialect override to reproduce the bug without an
external database.
was:
When a JDBC schema's dialect supports window functions (e.g. MySQL,
PostgreSQL), a query with CTE and RANK() throws AssertionError during
VolcanoPlanner optimization:
{code}
AssertionError: Relational expression
LogicalWindow.JDBC.TEST.[]
has calling-convention JDBC.TEST but does not implement the required interface
'interface org.apache.calcite.adapter.jdbc.JdbcRel' of that convention
{code}
h3. Reproduction
A JDBC schema with MySQL dialect ({{supportsWindowFunctions() = true}}), and a
query with CTE + RANK():
{code:sql}
WITH ranked AS (
SELECT customer_name, contract_amount,
RANK() OVER (ORDER BY contract_amount DESC) AS rnk
FROM sales_data
)
SELECT customer_name FROM ranked WHERE rnk <= 3
{code}
h3. Root cause
{{ProjectToLogicalProjectAndWindowRule}} has no convention restriction in its
operand definition:
{code:java}
// ProjectToWindowRule.java:196
.withOperandSupplier(b ->
b.operand(Project.class)
.predicate(Project::containsOver)
.anyInputs()) // trait=null matches ANY convention
{code}
When {{JdbcProjectRule}} first converts a {{LogicalProject}} with OVER to
{{JdbcProject}} (JDBC convention), and then
{{ProjectToLogicalProjectAndWindowRule}} fires on it, the JDBC traitSet
propagates through {{CalcRelSplitter}} to {{LogicalWindow.create()}}, causing
the AssertionError.
This is related to CALCITE-3352 (wrong collation on generated Window) — both
bugs share the same root cause: {{ProjectToWindowRule}} blindly propagates the
parent's traitSet to the generated {{LogicalWindow}}. Danny Chen commented on
CALCITE-3352:
{quote}
We should limit this rule to only match logical nodes because it is a plan
rewrite.
{quote}
h3. Fix
Add {{.trait(Convention.NONE)}} to the operand:
{code:java}
// ProjectToWindowRule.java
.withOperandSupplier(b ->
b.operand(Project.class)
.trait(Convention.NONE) // only match logical Project
.predicate(Project::containsOver)
.anyInputs())
{code}
h3. Impact
- When dialect supports window functions: window function is pushed down to
database via {{JdbcProject}}. Correct behavior.
- When dialect does NOT support window functions:
{{ProjectToLogicalProjectAndWindowRule}} fires on {{LogicalProject(NONE)}} as
before. No change.
h3. Scope
This is a targeted fix for the convention issue only. The collation issue
(CALCITE-3352) is tracked separately.
h3. Test
A JUnit test {{JdbcWindowConventionBugTest}} is provided in the PR, using
HSQLDB in-memory database with MySQL dialect override to reproduce the bug
without an external database.
> ProjectToLogicalProjectAndWindowRule should not match non-logical Project
> nodes with JDBC convention
> ----------------------------------------------------------------------------------------------------
>
> Key: CALCITE-7616
> URL: https://issues.apache.org/jira/browse/CALCITE-7616
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: leishp
> Assignee: leishp
> Priority: Major
> Labels: pull-request-available
>
> When a JDBC schema's dialect supports window functions (e.g. MySQL,
> PostgreSQL), a query with CTE and RANK() throws AssertionError during
> VolcanoPlanner optimization:
> {code}
> AssertionError: Relational expression
> LogicalWindow.JDBC.TEST.[]
> has calling-convention JDBC.TEST but does not implement the required
> interface
> 'interface org.apache.calcite.adapter.jdbc.JdbcRel' of that convention
> {code}
> h3. Reproduction
> A JDBC schema with MySQL dialect ({{supportsWindowFunctions() = true}}), and
> a query with CTE + RANK():
> {code:sql}
> WITH ranked AS (
> SELECT customer_name, contract_amount,
> RANK() OVER (ORDER BY contract_amount DESC) AS rnk
> FROM sales_data
> )
> SELECT customer_name FROM ranked WHERE rnk <= 3
> {code}
> h3. Root cause
> {{ProjectToLogicalProjectAndWindowRule}} passes the parent {{Project}}'s
> traitSet directly to {{LogicalWindow.create()}} via {{CalcRelSplitter}}. When
> the parent is a {{JdbcProject}} (JDBC convention), the generated
> {{LogicalWindow}} inherits the JDBC convention but does not implement the
> {{JdbcRel}} interface, causing an AssertionError in
> {{VolcanoPlanner.registerImpl}}.
> {code:java}
> // ProjectToWindowRule.java:161 — passes project.getTraitSet() directly
> final LogicalCalc calc =
> new LogicalCalc(project.getCluster(), project.getTraitSet(), // JDBC
> convention leaks in
> project.getHints(), input, program);
> {code}
> This is related to CALCITE-3352 (wrong collation on generated Window) — both
> bugs share the same root cause: {{ProjectToWindowRule}} blindly propagates
> the parent's traitSet to the generated {{LogicalWindow}}. Danny Chen
> commented on CALCITE-3352:
> {quote}
> We should limit this rule to only match logical nodes because it is a plan
> rewrite.
> {quote}
> h3. Fix
> Force {{Convention.NONE}} when creating the temporary {{LogicalCalc}}, so
> that {{LogicalWindow}} never inherits a non-NONE convention:
> {code:java}
> // ProjectToWindowRule.java
> final RelTraitSet traitSet =
> project.getCluster().traitSetOf(Convention.NONE); // force
> Convention.NONE
> final LogicalCalc calc =
> new LogicalCalc(project.getCluster(), traitSet,
> project.getHints(), input, program);
> {code}
> h3. Impact
> - When dialect supports window functions: window function is pushed down to
> database via {{JdbcProject}}. Correct behavior.
> - When dialect does NOT support window functions:
> {{ProjectToLogicalProjectAndWindowRule}} fires on {{LogicalProject(NONE)}} as
> before. No change.
> - No existing tests broken (verified {{RelOptRulesTest}} 902/902 passed).
> h3. Scope
> This is a targeted fix for the convention issue only. The collation issue
> (CALCITE-3352) is tracked separately.
> h3. Test
> A JUnit test {{JdbcWindowConventionTest}} is provided in the PR, using HSQLDB
> in-memory database with MySQL dialect override to reproduce the bug without
> an external database.
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