All Known Implementing Classes:

DelegatingTypeSystem, RelDataTypeSystemImpl
```
public interface RelDataTypeSystem
```
Type system.
Provides behaviors concerning type limits and behaviors. For example, in the default system, a DECIMAL can have maximum precision 19, but Hive overrides to 38.
The default implementation is DEFAULT.

Field Summary

Fields
Modifier and Type Field Description

static RelDataTypeSystem DEFAULT
Default type system.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`RelDataType`	`deriveAvgAggType(RelDataTypeFactory typeFactory, RelDataType argumentType)`	Returns the return type of a call to the `AVG`, `STDDEV` or `VAR` aggregate functions, inferred from its argument type.
`RelDataType`	`deriveCovarType(RelDataTypeFactory typeFactory, RelDataType arg0Type, RelDataType arg1Type)`	Returns the return type of a call to the `COVAR` aggregate function, inferred from its argument types.
`RelDataType`	`deriveFractionalRankType(RelDataTypeFactory typeFactory)`	Returns the return type of the `CUME_DIST` and `PERCENT_RANK` aggregate functions.
`RelDataType`	`deriveRankType(RelDataTypeFactory typeFactory)`	Returns the return type of the `NTILE`, `RANK`, `DENSE_RANK`, and `ROW_NUMBER` aggregate functions.
`RelDataType`	`deriveSumType(RelDataTypeFactory typeFactory, RelDataType argumentType)`	Returns the return type of a call to the `SUM` aggregate function, inferred from its argument type.
`int`	`getDefaultPrecision(SqlTypeName typeName)`	Returns default precision for this type if supported, otherwise -1 if precision is either unsupported or must be specified explicitly.
`java.lang.String`	`getLiteral(SqlTypeName typeName, boolean isPrefix)`	Returns the LITERAL string for the type, either PREFIX/SUFFIX.
`int`	`getMaxNumericPrecision()`	Returns the maximum precision of a NUMERIC or DECIMAL type.
`int`	`getMaxNumericScale()`	Returns the maximum scale of a NUMERIC or DECIMAL type.
`int`	`getMaxPrecision(SqlTypeName typeName)`	Returns the maximum precision (or length) allowed for this type, or -1 if precision/length are not applicable for this type.
`int`	`getMaxScale(SqlTypeName typeName)`	Returns the maximum scale of a given type.
`int`	`getNumTypeRadix(SqlTypeName typeName)`	Returns the numeric type radix, typically 2 or 10.
`boolean`	`isAutoincrement(SqlTypeName typeName)`	Returns whether the type can be auto increment.
`boolean`	`isCaseSensitive(SqlTypeName typeName)`	Returns whether the type is case sensitive.
`boolean`	`isSchemaCaseSensitive()`	Whether two record types are considered distinct if their field names are the same but in different cases.
`boolean`	`shouldConvertRaggedUnionTypesToVarying()`	Whether the least restrictive type of a number of CHAR types of different lengths should be a VARCHAR type.

- Field Detail
  - DEFAULT
```
static final RelDataTypeSystem DEFAULT
```
    Default type system.
- Method Detail
  - getMaxScale
```
int getMaxScale(SqlTypeName typeName)
```
    Returns the maximum scale of a given type.
  - getDefaultPrecision
```
int getDefaultPrecision(SqlTypeName typeName)
```
    Returns default precision for this type if supported, otherwise -1 if precision is either unsupported or must be specified explicitly.
    
    Returns:
    
    Default precision
  - getMaxPrecision
```
int getMaxPrecision(SqlTypeName typeName)
```
    Returns the maximum precision (or length) allowed for this type, or -1 if precision/length are not applicable for this type.
    
    Returns:
    
    Maximum allowed precision
  - getMaxNumericScale
```
int getMaxNumericScale()
```
    Returns the maximum scale of a NUMERIC or DECIMAL type.
  - getMaxNumericPrecision
```
int getMaxNumericPrecision()
```
    Returns the maximum precision of a NUMERIC or DECIMAL type.
  - getLiteral
```
java.lang.String getLiteral(SqlTypeName typeName,
                            boolean isPrefix)
```
    Returns the LITERAL string for the type, either PREFIX/SUFFIX.
  - isCaseSensitive
```
boolean isCaseSensitive(SqlTypeName typeName)
```
    Returns whether the type is case sensitive.
  - isAutoincrement
```
boolean isAutoincrement(SqlTypeName typeName)
```
    Returns whether the type can be auto increment.
  - getNumTypeRadix
```
int getNumTypeRadix(SqlTypeName typeName)
```
    Returns the numeric type radix, typically 2 or 10. 0 means "not applicable".
  - deriveSumType
```
RelDataType deriveSumType(RelDataTypeFactory typeFactory,
                          RelDataType argumentType)
```
    Returns the return type of a call to the SUM aggregate function, inferred from its argument type.
  - deriveAvgAggType
```
RelDataType deriveAvgAggType(RelDataTypeFactory typeFactory,
                             RelDataType argumentType)
```
    Returns the return type of a call to the AVG, STDDEV or VAR aggregate functions, inferred from its argument type.
  - deriveCovarType
```
RelDataType deriveCovarType(RelDataTypeFactory typeFactory,
                            RelDataType arg0Type,
                            RelDataType arg1Type)
```
    Returns the return type of a call to the COVAR aggregate function, inferred from its argument types.
  - deriveFractionalRankType
```
RelDataType deriveFractionalRankType(RelDataTypeFactory typeFactory)
```
    Returns the return type of the CUME_DIST and PERCENT_RANK aggregate functions.
  - deriveRankType
```
RelDataType deriveRankType(RelDataTypeFactory typeFactory)
```
    Returns the return type of the NTILE, RANK, DENSE_RANK, and ROW_NUMBER aggregate functions.
  - isSchemaCaseSensitive
```
boolean isSchemaCaseSensitive()
```
    Whether two record types are considered distinct if their field names are the same but in different cases.
  - shouldConvertRaggedUnionTypesToVarying
```
boolean shouldConvertRaggedUnionTypesToVarying()
```
    Whether the least restrictive type of a number of CHAR types of different lengths should be a VARCHAR type. And similarly BINARY to VARBINARY.

Interface RelDataTypeSystem

Field Summary

Method Summary

Field Detail

DEFAULT

Method Detail

getMaxScale

getDefaultPrecision

getMaxPrecision

getMaxNumericScale

getMaxNumericPrecision

getLiteral

isCaseSensitive

isAutoincrement

getNumTypeRadix

deriveSumType

deriveAvgAggType

deriveCovarType

deriveFractionalRankType

deriveRankType

isSchemaCaseSensitive

shouldConvertRaggedUnionTypesToVarying