TupleCorrelation Class Reference

Public Member Functions
	TupleCorrelation (Uint32 val)
Uint32	toUint32 () const
Uint16	getTupleId () const
Uint16	getParentTupleId () const

Static Public Attributes
static const Uint32	wordCount = 1

Detailed Description

A class for accessing the correlation data at the end of a tuple (for scan queries). These data have the following layout:

Word 0: AttributeHeader Word 1, upper halfword: tuple id of parent tuple. Word 1, lower halfword: tuple id of this tuple. Word 2: Id of receiver for root operation (where the ancestor tuple of this tuple will go).

Both tuple identifiers are unique within this batch and root fragment. With these identifiers, it is possible to relate a tuple to its parent and children. That way, results for child operations can be updated correctly when the application iterates over the results of the root scan operation.

Definition at line 107 of file NdbQueryOperation.cpp.

Constructor & Destructor Documentation

TupleCorrelation::TupleCorrelation ( Uint32  val )

inlineexplicit

Conversion to/from Uint32 to store/fetch from buffers

Definition at line 117 of file NdbQueryOperation.cpp.

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

• storage/ndb/src/ndbapi/NdbQueryOperation.cpp