This is the tuple manager, which manages the physical storage of
cluster data. It consists of the following files found in the
AttributeOffset.hpp: Defines the
AttributeOffset class, which models the
structure of an attribute, permitting up to 4096 attributes,
all of which are nullable.
DbtupDiskAlloc.cpp: Handles allocation
and deallocation of extents for disk space.
DbtupIndex.cpp: Implements methods for
reading and writing tuples using ordered indexes.
DbtupScan.cpp: Implements methods for
tuppage.cpp: Handles allocating pages
for writing tuples.
tuppage.hpp: Defines structures for
fixed and variable size data pages for tuples.
DbtupAbort.cpp: Contains routines for
terminating failed tuple operations.
DbtupExecQuery.cpp: Handles execution
of queries for tuples and reading from them.
DbtupMeta.cpp: Handle table operations
DbtupStoredProcDef.cpp: Module for
adding and dropping procedures.
DbtupBuffer.cpp: Handles read/write
buffers for tuple operations.
DbtupFixAlloc.cpp: Allocates and frees
fixed-size tuples from the set of pages attatched to a
fragment. The fixed size is set per fragment; there can be
only one such value per fragment.
DbtupPageMap.cpp: Routines used by
Dbtup to map logical page IDs to physical
page IDs. The mapping needs the fragment ID and the logical
page ID to provide the physical ID. This part of
Dbtup is the exclusive user of a certain
set of variables on the fragment record; it is also the
exclusive user of the struct for page ranges (the
PageRange struct defined in
DbtupTabDesMan.cpp: This file contains
the routines making up the table descriptor memory manager.
Each table has a descriptor, which is a contiguous array of
data words, and which is allocated from a global array using
a “buddy” algorithm, with free lists existing
for each 2N words.
Notes.txt: Contains some developers'
implementation notes on tuples, tuple operations, and tuple
Undo_buffer.hpp: Defines the
Undo_buffer class, used for storage of
operations that may need to be rolled back.
Undo_buffer.cpp: Implements some
DbtupCommit.cpp: Contains routines used
to commit operations on tuples to disk.
DbtupGen.cpp: This file contains
Dbtup initialization routines.
DbtupPagMan.cpp: This file implements
the page memory manager's “buddy” algorithm.
PagMan is invoked when fragments lack
sufficient internal page space to accommodate all the data
they are requested to store. It is also invoked when
fragments deallocate page space back to the free area.
DbtupTrigger.cpp: The routines
contained in this file perform handling of
NDB internal triggers.
DbtupDebug.cpp: Used for debugging
Dbtup.hpp: Contains the
Dbtup class definition. Also defines a
number of essential structures such as tuple scans, disk
allocation units, fragment records, and so on.
Dbtup routines for reading attributes.
test_varpage.cpp: Simple test program
for verifying variable-size page operations.
This block also monitors changes in tuples.