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secondo/Algebras/CRel2/BinaryTuple.h
2026-01-23 17:03:45 +08:00

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/*
----
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Copyright (C) 2004, University in Hagen, Department of Computer Science,
Database Systems for New Applications.
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----
//paragraph [10] title: [{\Large \bf ] [}]
//paragraph [21] table1column: [\begin{quote}\begin{tabular}{l}] [\end{tabular}\end{quote}]
//paragraph [22] table2columns: [\begin{quote}\begin{tabular}{ll}] [\end{tabular}\end{quote}]
//paragraph [23] table3columns: [\begin{quote}\begin{tabular}{lll}] [\end{tabular}\end{quote}]
//paragraph [24] table4columns: [\begin{quote}\begin{tabular}{llll}] [\end{tabular}\end{quote}]
//[--------] [\hline]
//characters [1] verbatim: [$] [$]
//characters [2] formula: [$] [$]
//characters [3] capital: [\textsc{] [}]
//characters [4] teletype: [\texttt{] [}]
//[ae] [\"a]
//[oe] [\"o]
//[ue] [\"u]
//[ss] [{\ss}]
//[<=] [\leq]
//[#] [\neq]
//[tilde] [\verb|~|]
December 07, 2017
Author: Nicolas Napp
\tableofcontents
1 Header File: BinaryTuple.h
*/
#ifndef BINARYTUPLE_H_
#define BINARYTUPLE_H_
#include <cstdint>
/*
~BinaryTuples~ are needed to store the extracted ~relevant~ data from the argument tuple blocks, which are currently materialized in the ~ccPartHashJoin~ operator. The size of a ~binary tuple~ is determined dynamically at runtime. They come in three different sizes:
\begin{itemize}
\item binaryTupleSmall (4 Byte),
\item binaryTupleMedium (8 Byte), or
\item binaryTupleLarge (16 Byte).
\end{itemize}
The goal is to use the smallest size possible and still be able to encode a reference to any tuple (i.e. the tuple block and row number) in the field ~tupelref~.
*/
namespace CRel2Algebra {
struct binaryTupleSmall // size = 4 Bytes
{
binaryTupleSmall() :
tupleref { 0 }, hashvalue { 0 }
{
}
uint16_t tupleref; // exactly 16 Bit; needs <cstdint>
uint16_t hashvalue;
};
struct binaryTupleMedium // size = 8 Bytes
{
binaryTupleMedium() :
tupleref { 0 }, hashvalue { 0 }
{
}
uint32_t tupleref; // exactly 32 Bit; needs <cstdint>
uint32_t hashvalue;
};
struct binaryTupleLarge // size = 16 Bytes
{
binaryTupleLarge() :
tupleref { 0 }, hashvalue { 0 }
{
}
uint64_t tupleref; // exactly 64 Bit; needs <cstdint>
uint64_t hashvalue;
};
} /* namespace CRel2Algebra */
#endif /* BINARYTUPLE_H_ */