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DB Java Edition version 1.7.1 |
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java.lang.Objectcom.sleepycat.je.Database
com.sleepycat.je.SecondaryDatabase
A secondary database handle.
Secondary databases are opened with Environment.openSecondaryDatabase
and are always associated with a single primary database. The
distinguishing characteristics of a secondary database are:
put()
methods on a secondary database are
prohibited.delete
method of a secondary database will delete the primary record and as
well as all its associated secondary records.get()
methods will return the data
from the associated primary database.get()
method signatures are provided
to return the primary key in an additional pKey
parameter.openCursor
will return a SecondaryCursor
,
which itself has get()
methods that return the data of the
primary database and additional get()
method signatures
for returning the primary key.openSecondaryCursor
method is provided to return a SecondaryCursor
that doesn't require casting.
Before opening or creating a secondary database you must implement the SecondaryKeyCreator interface. For example:
class MyKeyCreator implements SecondaryKeyCreator { public boolean createSecondaryKey(SecondaryDatabase secondary, DatabaseEntry key, DatabaseEntry data, DatabaseEntry result) throws DatabaseException { // // DO HERE: Extract the secondary key from the primary key and data, // and set the secondary key into the result parameter. // return true; } }
To create a secondary database that supports duplicates:
Database primaryDb; // The primary database must already be open. SecondaryConfig secConfig = new SecondaryConfig(); secConfig.setAllowCreate(true); secConfig.setSortedDuplicates(true); secConfig.setKeyCreator(new MyKeyCreator()); SecondaryDatabase newDb = env.openSecondaryDatabase(txn, "foo", primaryDb, secConfig)
If a primary database is to be associated with one or more secondary databases, it may not be configured for duplicates.
Method Summary | |
void |
close()
Closes a secondary database and dis-associates it from its primary database. |
OperationStatus |
delete(Transaction txn, DatabaseEntry key) Deletes the key/data pair from the associated primary database and all secondary indices. |
OperationStatus |
get(Transaction txn, DatabaseEntry key, DatabaseEntry pKey, DatabaseEntry data, LockMode lockMode) Retrieves the key/data pair with the given key. |
OperationStatus |
get(Transaction txn, DatabaseEntry key, DatabaseEntry data, LockMode lockMode) Retrieves the key/data pair with the given key. |
Database |
getPrimaryDatabase()
Returns the primary database associated with this secondary database. |
OperationStatus |
getSearchBoth(Transaction txn, DatabaseEntry key, DatabaseEntry pKey, DatabaseEntry data, LockMode lockMode) Retrieves the key/data pair with the specified secondary and primary key, that is, both the primary and secondary key items must match. |
OperationStatus |
getSearchBoth(Transaction txn, DatabaseEntry key, DatabaseEntry data, LockMode lockMode) This operation is not allowed with this method signature. |
SecondaryConfig |
getSecondaryConfig()
Returns a copy of the secondary configuration of this database. |
JoinCursor |
join(Cursor[] cursors, JoinConfig config) This operation is not allowed on a secondary database. |
SecondaryCursor |
openSecondaryCursor(Transaction txn, CursorConfig cursorConfig)
Obtain a cursor on a database, returning a SecondaryCursor . |
OperationStatus |
put(Transaction txn, DatabaseEntry key, DatabaseEntry data) This operation is not allowed on a secondary database. |
OperationStatus |
putNoDupData(Transaction txn, DatabaseEntry key, DatabaseEntry data) This operation is not allowed on a secondary database. |
OperationStatus |
putNoOverwrite(Transaction txn, DatabaseEntry key, DatabaseEntry data) This operation is not allowed on a secondary database. |
int |
truncate(Transaction txn,
boolean countRecords) This operation is not allowed on a secondary database. |
Methods inherited from class com.sleepycat.je.Database |
getConfig,
getDatabaseName,
getEnvironment,
getSecondaryDatabases,
getStats,
openCursor,
preload,
verify |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Method Detail |
public SecondaryConfig getSecondaryConfig() throws DatabaseException
DatabaseException
- if a
failure occurs.
public OperationStatus get(Transaction txn, DatabaseEntry key, DatabaseEntry pKey, DatabaseEntry data, LockMode lockMode) throws DatabaseException
Cursor
operations.
txn
- For a transactional database, an explicit
transaction may be specified to transaction-protect the operation, or
null may be specified to perform the operation without transaction
protection. For a non-transactional database, null must be specified.
key
- the secondary key used as input. It must
be initialized with a non-null byte array by the caller.
pKey
- the primary key returned as output. Its
byte array does not need to be initialized by the caller.
data
- the primary data returned as output. Its
byte array does not need to be initialized by the caller.
lockMode
- the locking attributes; if null,
default attributes are used.
OperationStatus.NOTFOUND
if no matching key/data pair is found; otherwise, OperationStatus.SUCCESS
.
DeadlockException
- if the
operation was selected to resolve a deadlock.
IllegalArgumentException
- if an invalid parameter was specified.
DatabaseException
- if a
failure occurs.
public OperationStatus getSearchBoth(Transaction txn, DatabaseEntry key, DatabaseEntry pKey, DatabaseEntry data, LockMode lockMode) throws DatabaseException
txn
- For a transactional database, an explicit
transaction may be specified to transaction-protect the operation, or
null may be specified to perform the operation without transaction
protection. For a non-transactional database, null must be specified.
key
- the secondary key used as input. It must
be initialized with a non-null byte array by the caller.
pKey
- the primary key used as input. It must be
initialized with a non-null byte array by the caller.
data
- the primary data returned as output. Its
byte array does not need to be initialized by the caller.
lockMode
- the locking attributes; if null,
default attributes are used.
OperationStatus.NOTFOUND
if no matching key/data pair is found; otherwise, OperationStatus.SUCCESS
.
DeadlockException
- if the
operation was selected to resolve a deadlock.
IllegalArgumentException
- if an invalid parameter was specified.
DatabaseException
- if a
failure occurs.
public Database getPrimaryDatabase() throws DatabaseException
DatabaseException
- if a
failure occurs.
public SecondaryCursor openSecondaryCursor(Transaction txn, CursorConfig cursorConfig) throws DatabaseException
SecondaryCursor
.
Calling this method is the equivalent of calling Database.openCursor(com.sleepycat.je.Transaction,
com.sleepycat.je.CursorConfig)
and casting the result to SecondaryCursor
.
txn
- To use a cursor for writing to a
transactional database, an explicit transaction must be specified. For
read-only access to a transactional database, the transaction may be
null. For a non-transactional database, the transaction must be null.
To transaction-protect cursor operations, cursors must be opened and closed within the context of a transaction, and the txn parameter specifies the transaction context in which the cursor will be used.
cursorConfig
- The cursor attributes. If null,
default attributes are used.
DatabaseException
- if a
failure occurs.
public void close() throws DatabaseException
Flush any cached database information to disk and discard the database handle.
The database handle should not be closed while any other handle
that refers to it is not yet closed; for example, database handles
should not be closed while cursor handles into the database remain
open, or transactions that include operations on the database have not
yet been committed or aborted. Specifically, this includes Cursor
and Transaction
handles.
When multiple threads are using the Database
handle
concurrently, only a single thread may call this method.
The database handle may not be accessed again after this method is called, regardless of the method's success or failure.
When called on a database that is the primary database for a secondary index, the primary database should be closed only after all secondary indices which reference it have been closed.
close
in
class Database
DatabaseException
- if a
failure occurs.
public OperationStatus delete(Transaction txn, DatabaseEntry key) throws DatabaseException
This method behaves as if Database.delete(com.sleepycat.je.Transaction,
com.sleepycat.je.DatabaseEntry)
were called for the primary database,
using the primary key obtained via the secondary key parameter.
delete
in class Database
txn
- For a transactional database, an explicit
transaction may be specified, or null may be specified to use
auto-commit. For a non-transactional database, null must be specified.
key
- the key DatabaseEntry
operated on.
OperationStatus.NOTFOUND
if the specified key is not found in the database; otherwise the
method will return OperationStatus.SUCCESS
.
DatabaseException
- if a
failure occurs.
public OperationStatus get(Transaction txn, DatabaseEntry key, DatabaseEntry data, LockMode lockMode) throws DatabaseException
Cursor
operations.
get
in class Database
txn
- For a transactional database, an explicit
transaction may be specified to transaction-protect the operation, or
null may be specified to perform the operation without transaction
protection. For a non-transactional database, null must be specified.
key
- the secondary key used as input. It must
be initialized with a non-null byte array by the caller.
data
- the primary data returned as output. Its
byte array does not need to be initialized by the caller.
lockMode
- the locking attributes; if null,
default attributes are used.
OperationStatus.NOTFOUND
if no matching key/data pair is found; otherwise, OperationStatus.SUCCESS
.
DeadlockException
- if the
operation was selected to resolve a deadlock.
IllegalArgumentException
- if an invalid parameter was specified.
DatabaseException
- if a
failure occurs.
public OperationStatus getSearchBoth(Transaction txn, DatabaseEntry key, DatabaseEntry data, LockMode lockMode) throws DatabaseException
UnsupportedOperationException
will always be thrown by this method. The corresponding method with the
pKey
parameter should be used instead.
getSearchBoth
in class Database
txn
- For a transactional database, an explicit
transaction may be specified to transaction-protect the operation, or
null may be specified to perform the operation without transaction
protection. For a non-transactional database, null must be specified.
key
- the key used as input. It must be
initialized with a non-null byte array by the caller.
data
- the data used as input. It must be
initialized with a non-null byte array by the caller.
lockMode
- the locking attributes; if null,
default attributes are used.
OperationStatus.NOTFOUND
if no matching key/data pair is found; otherwise, OperationStatus.SUCCESS
.
DatabaseException
- if a
failure occurs.
public OperationStatus put(Transaction txn, DatabaseEntry key, DatabaseEntry data) throws DatabaseException
UnsupportedOperationException
will always be thrown by this method. The corresponding method on the
primary database should be used instead.
put
in class Database
txn
- For a transactional database, an explicit
transaction may be specified, or null may be specified to use
auto-commit. For a non-transactional database, null must be specified.
key
- the key DatabaseEntry
operated on.
data
- the data DatabaseEntry
stored.
DatabaseException
- if a
failure occurs.
public OperationStatus putNoOverwrite(Transaction txn, DatabaseEntry key, DatabaseEntry data) throws DatabaseException
UnsupportedOperationException
will always be thrown by this method. The corresponding method on the
primary database should be used instead.
putNoOverwrite
in class Database
txn
- For a transactional database, an explicit
transaction may be specified, or null may be specified to use
auto-commit. For a non-transactional database, null must be specified.
key
- the key DatabaseEntry
operated on.
data
- the data DatabaseEntry
stored.
OperationStatus.KEYEXIST
.
DatabaseException
- if a
failure occurs.
public OperationStatus putNoDupData(Transaction txn, DatabaseEntry key, DatabaseEntry data) throws DatabaseException
UnsupportedOperationException
will always be thrown by this method. The corresponding method on the
primary database should be used instead.
putNoDupData
in class Database
txn
- For a transactional database, an explicit
transaction may be specified, or null may be specified to use
auto-commit. For a non-transactional database, null must be specified.
key
- the key DatabaseEntry
operated on.
data
- the data DatabaseEntry
stored.
OperationStatus.KEYEXIST
.
DatabaseException
- if a
failure occurs.
public JoinCursor join(Cursor[] cursors, JoinConfig config) throws DatabaseException
UnsupportedOperationException
will always be thrown by this method. The corresponding method on the
primary database should be used instead.
join
in class Database
cursors
- an array of cursors associated with
this primary database.
config
- The join attributes. If null, default
attributes are used.
DatabaseException
- if a
failure occurs.
JoinCursor
public int truncate(Transaction txn, boolean countRecords) throws DatabaseException
UnsupportedOperationException
will always be thrown by this method. The corresponding method on the
primary database should be used instead.
truncate
in class Database
txn
- For a transactional database, an explicit
transaction may be specified, or null may be specified to use
auto-commit. For a non-transactional database, null must be specified.
countRecords
- If true, count and return the
number of records discarded.
DatabaseException
- if a
failure occurs.
|
Berkeley
DB Java Edition version 1.7.1 |
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