A conglomerate is an abstract storage structure (they
correspond to access methods). The Conglomerate interface
corresponds to a single instance of a conglomerate. In
other words, for each conglomerate in the system, there
will be one object implementing Conglomerate.
The Conglomerate interface is implemented by each access method.
The implementation must maintain enough information to properly
open the conglomerate and scans, and to drop the conglomerate.
This information typically will include the id of the container
or containers in which the conglomerate is stored, and my also
include property information.
Conglomerates are created by a conglomerate factory. The access
manager stores them in a directory (which is why they implement
Storable).
| Method from org.apache.derby.iapi.store.access.conglomerate.Conglomerate Detail: |
|---|
 public void addColumn(TransactionManager xact_manager,
int column_id,
Storable template_column,
int collation_id) throws StandardException
Add a column to the conglomerate.
This routine update's the in-memory object version of the
Conglomerate to have one more column of the type described by the
input template column.
Note that not all conglomerates may support this feature. |
public void compressConglomerate(TransactionManager xact_manager,
Transaction rawtran) throws StandardException |
public ScanManager defragmentConglomerate(TransactionManager xact_manager,
Transaction rawtran,
boolean hold,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level) throws StandardException Online compress table.
Returns a ScanManager which can be used to move rows
around in a table, creating a block of free pages at the end of the
table. The process of executing the scan will move rows from the end
of the table toward the beginning. The GroupFetchScanController will
return the old row location, the new row location, and the actual data
of any row moved. Note that this scan only returns moved rows, not an
entire set of rows, the scan is designed specifically to be
used by either explicit user call of the SYSCS_ONLINE_COMPRESS_TABLE()
procedure, or internal background calls to compress the table.
The old and new row locations are returned so that the caller can
update any indexes necessary.
This scan always returns all collumns of the row.
All inputs work exactly as in openScan(). The return is
a GroupFetchScanController, which only allows fetches of groups
of rows from the conglomerate.
Note that all Conglomerates may not implement openCompressScan(),
currently only the Heap conglomerate implements this scan. |
public void drop(TransactionManager xact_manager) throws StandardException |
public boolean fetchMaxOnBTree(TransactionManager xact_manager,
Transaction rawtran,
long conglomId,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level,
FormatableBitSet scanColumnList,
DataValueDescriptor[] fetchRow) throws StandardException Retrieve the maximum value row in an ordered conglomerate.
Returns true and fetches the rightmost row of an ordered conglomerate
into "fetchRow" if there is at least one row in the conglomerate. If
there are no rows in the conglomerate it returns false.
Non-ordered conglomerates will not implement this interface, calls
will generate a StandardException.
RESOLVE - this interface is temporary, long term equivalent (and more)
functionality will be provided by the openBackwardScan() interface. |
public long getContainerid() |
public DynamicCompiledOpenConglomInfo getDynamicCompiledConglomInfo() throws StandardException Return dynamic information about the conglomerate to be dynamically
reused in repeated execution of a statement.
The dynamic info is a set of variables to be used in a given
ScanController or ConglomerateController. It can only be used in one
controller at a time. It is up to the caller to insure the correct
thread access to this info. The type of info in this is a scratch
template for btree traversal, other scratch variables for qualifier
evaluation, ...
|
public ContainerKey getId() Get the id of the container of the conglomerate.
Will have to change when a conglomerate could have more than one
container. The ContainerKey is a combination of the container id
and segment id. |
public StaticCompiledOpenConglomInfo getStaticCompiledConglomInfo(TransactionController tc,
long conglomId) throws StandardException Return static information about the conglomerate to be included in a
a compiled plan.
The static info would be valid until any ddl was executed on the
conglomid, and would be up to the caller to throw away when that
happened. This ties in with what language already does for other
invalidation of static info. The type of info in this would be
containerid and array of format id's from which templates can be created.
The info in this object is read only and can be shared among as many
threads as necessary.
|
public boolean isTemporary() Is this conglomerate temporary?
|
public long load(TransactionManager xact_manager,
boolean createConglom,
RowLocationRetRowSource rowSource) throws StandardException Bulk load into the conglomerate.
Individual rows that are loaded into the conglomerate are not
logged. After this operation, the underlying database must be backed up
with a database backup rather than an transaction log backup (when we
have them). This warning is put here for the benefit of future
generation.
|
public ConglomerateController open(TransactionManager xact_manager,
Transaction rawtran,
boolean hold,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
StaticCompiledOpenConglomInfo static_info,
DynamicCompiledOpenConglomInfo dynamic_info) throws StandardException Open a conglomerate controller.
|
public ScanManager openScan(TransactionManager xact_manager,
Transaction rawtran,
boolean hold,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level,
FormatableBitSet scanColumnList,
DataValueDescriptor[] startKeyValue,
int startSearchOperator,
Qualifier[][] qualifier,
DataValueDescriptor[] stopKeyValue,
int stopSearchOperator,
StaticCompiledOpenConglomInfo static_info,
DynamicCompiledOpenConglomInfo dynamic_info) throws StandardException |
public StoreCostController openStoreCost(TransactionManager xact_manager,
Transaction rawtran) throws StandardException Return an open StoreCostController for the conglomerate.
Return an open StoreCostController which can be used to ask about
the estimated row counts and costs of ScanController and
ConglomerateController operations, on the given conglomerate.
|
public void purgeConglomerate(TransactionManager xact_manager,
Transaction rawtran) throws StandardException |
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