[
https://issues.apache.org/jira/browse/CALCITE-2082?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Julian Hyde updated CALCITE-2082:
---------------------------------
Description:
Do not store types (RelDataType) or type factories (RelDataTypeFactory) in
SqlOperator instances.
*Rationale*: a {{SqlOperator}} has a lifetime that spans many statements; but a
type factory is only for one statement, and each type belongs to that factory.
We want to share {{SqlOperator}} instances across connections, therefore we
need to create them before there is a type factory.
Typically, a method that returns a type should have a type factory argument
with which to create it.
The current situation is technical debt. There are a couple of pieces of code
tagged with this case number; see the fix to CALCITE-2072.
In particular:
* Remove method {{List<RelDataType> SqlOperator.getParamTypes()}};
* Remove {{RelDataTypeFactory}} argument from {{SqlUserDefinedAggFunction}}
constructor, and remove its {{typeFactory}} field.
We will add {{interface SqlOperandMetadata extends SqlOperatorTypeChecker}},
which has new methods {{List<RelDataType>> paramTypes(RelDataTypeFactory)}} and
{{List<String> paramNames()}}.
This interface will typically be implemented only for user-defined functions.
Unlike SQL built-in functions, UDFs have a fixed set of parameters (although
some of them may be optional), and the parameters have names.
In {{interface SqlOperandTypeChecker}}, add method {{boolean
isFixedParameters()}}. Will typically return true for UDFs, false for built-in
functions. Returns false for table window functions (e.g. {{HOP}}), even though
these have named parameters (which tends to make them look a bit like UDFs).
was:
Remove RelDataTypeFactory argument from SqlUserDefinedAggFunction constructor.
We want to share SqlOperator instances across connections, therefore we need to
create them before there is a type factory.
The current situation is technical debt. There are a couple of pieces of code
tagged with this case number; see the fix to CALCITE-2072.
> Do not store types or type factories inside operators
> -----------------------------------------------------
>
> Key: CALCITE-2082
> URL: https://issues.apache.org/jira/browse/CALCITE-2082
> Project: Calcite
> Issue Type: Bug
> Reporter: Julian Hyde
> Assignee: Julian Hyde
> Priority: Major
> Fix For: 1.26.0
>
>
> Do not store types (RelDataType) or type factories (RelDataTypeFactory) in
> SqlOperator instances.
> *Rationale*: a {{SqlOperator}} has a lifetime that spans many statements; but
> a type factory is only for one statement, and each type belongs to that
> factory. We want to share {{SqlOperator}} instances across connections,
> therefore we need to create them before there is a type factory.
> Typically, a method that returns a type should have a type factory argument
> with which to create it.
> The current situation is technical debt. There are a couple of pieces of code
> tagged with this case number; see the fix to CALCITE-2072.
> In particular:
> * Remove method {{List<RelDataType> SqlOperator.getParamTypes()}};
> * Remove {{RelDataTypeFactory}} argument from {{SqlUserDefinedAggFunction}}
> constructor, and remove its {{typeFactory}} field.
> We will add {{interface SqlOperandMetadata extends SqlOperatorTypeChecker}},
> which has new methods {{List<RelDataType>> paramTypes(RelDataTypeFactory)}}
> and {{List<String> paramNames()}}.
> This interface will typically be implemented only for user-defined functions.
> Unlike SQL built-in functions, UDFs have a fixed set of parameters (although
> some of them may be optional), and the parameters have names.
> In {{interface SqlOperandTypeChecker}}, add method {{boolean
> isFixedParameters()}}. Will typically return true for UDFs, false for
> built-in functions. Returns false for table window functions (e.g. {{HOP}}),
> even though these have named parameters (which tends to make them look a bit
> like UDFs).
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
