tmudr::TableInfo Class Reference

Describes a table-valued input or a table-valued output. More...

#include <sqludr.h>

Inheritance diagram for tmudr::TableInfo:

Public Member Functions
long	getEstimatedNumRows () const
long	getEstimatedNumPartitions () const
const PartitionInfo &	getQueryPartitioning () const
const OrderInfo &	getQueryOrdering () const
bool	isStream () const
int	getNumConstraints () const
const ConstraintInfo &	getConstraint (int i) const
void	setEstimatedNumRows (long rows)
void	addCardinalityConstraint (const CardinalityConstraintInfo &constraint)
void	addUniquenessConstraint (const UniqueConstraintInfo &constraint)
void	setIsStream (bool stream)
void	print ()

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Detailed Description

Describes a table-valued input or a table-valued output.

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Member Function Documentation

void TableInfo::addCardinalityConstraint

(

const CardinalityConstraintInfo &

constraint

)

Add a cardinality constraint to the UDF table-valued output.

Only use this method from within the following methods:

• UDR::describeParamsAndColumns()
• UDR::describeDataflowAndPredicates()
• UDR::describeConstraints()

Parameters:

constraint

New constraint to add. The object needs to be deallocated by the caller after this call returns.

Exceptions:

UDRException

void TableInfo::addUniquenessConstraint

(

const UniqueConstraintInfo &

constraint

)

Add a uniqueness constraint to the UDF table-valued output.

Only use this method from within the following methods:

• UDR::describeParamsAndColumns()
• UDR::describeDataflowAndPredicates()
• UDR::describeConstraints()

Parameters:

constraint

New uniqueness constraint to add. The object needs to be deallocated by the caller after this call returns.

Exceptions:

UDRException

const ConstraintInfo & TableInfo::getConstraint

(

int

i

)

const

Get a constraint by index/ordinal number.

Parameters:

i

index/ordinal (0-based) of the constraint.

Returns:

Constraint for a given index/ordinal.

Exceptions:

UDRException

long TableInfo::getEstimatedNumPartitions

(

)

const

For tables with a PARTITION BY, get estimated number of partitions.

See also:

getEstimatedNumRows()

setEstimatedNumRows()

Returns:

Estimated number of partitions or -1 if there is no estimate or no PARTITION BY.

long TableInfo::getEstimatedNumRows

(

)

const

Get the estimated number of rows of this table.

See also:

setEstimatedNumRows()

getEstimatedNumPartitions()

Returns:

Estimated number of rows or -1 if there is no estimate.

int TableInfo::getNumConstraints

(

)

const

Get the number of constraints defined on this table.

Returns:

Number of constraints defined on this table.

const OrderInfo & TableInfo::getQueryOrdering

(

)

const

Get the ORDER BY clause for this input table.

This returns either the ORDER BY clause specified in the SQL query, or the updated ordering information, set by UDRInvocationInfo::setChildOrdering(), called during UDR::describeParamsAndColumns().

Returns:

Ordering clause for this input table.

const PartitionInfo & TableInfo::getQueryPartitioning

(

)

const

Get the PARTITION BY clause for this input table.

This returns either the PARTITION BY clause specified in the SQL query, or the updated partitioning information, set by UDRInvocationInfo::setChildPartitioning(), called during UDR::describeParamsAndColumns().

Returns:

Partitioning clause for this input table.

bool TableInfo::isStream

(

)

const

Returns whether the UDF result is treated as a continuous stream.

Note: This is currently not supported. The method always returns false for now.

Returns:

true if the UDF result is a stream, false otherwise.

void TableInfo::print

(

)

Print the object, for use in debugging.

See also:

UDR::debugLoop()

UDRInvocationInfo::PRINT_INVOCATION_INFO_AT_RUN_TIME

Reimplemented from tmudr::TupleInfo.

void TableInfo::setEstimatedNumRows

(

long

rows

)

Set the estimated number of rows for a UDF table-valued result.

Setting this value can help the Trafodion optimizer generate a better plan for queries containing table-valued UDFs. Note that this is only an estimate, a strict correspondence to the actual number of rows returned at runtime is not required.

Only use this method from within the following methods:

• UDR::describeParamsAndColumns()
• UDR::describeDataflowAndPredicates()
• UDR::describeConstraints()
• UDR::describeStatistics()

Parameters:

rows

Estimated number of rows for this table.

void TableInfo::setIsStream

(

bool

stream

)

Set whether a table should be treated as a stream.

This method is not yet supported.

Parameters:

stream

true if the table is a stream, false otherwise.

Exceptions:

UDRException

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The documentation for this class was generated from the following files:

• sqludr.h
• sqludr.cpp