Berkeley DB: Dbc.dup
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++

# Dbc.dup |

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    import com.sleepycat.db.*;

    public Dbc dup(int flags)
    	throws DbException;

# Description

The Dbc.dup method creates a new cursor that uses the same transaction and locker ID as the original cursor. This is useful when an application is using locking and requires two or more cursors in the same thread of control.

The flags value must be set to 0 or by bitwise inclusively OR'ing together one or more of the following values:

Db.DB_POSITION
  The newly created cursor is initialized to refer to the same position in the database as the original cursor and hold the same locks. If the Db.DB_POSITION flag is not specified, then the created cursor is uninitialized and will behave like a cursor newly created using Db.cursor.

When using the Berkeley DB Concurrent Data Store product, there can be only one active write cursor at a time. For this reason, attempting to duplicate a cursor for which the Db.DB_WRITECURSOR flag was specified during creation will return an error.

If the cursor argument is not yet initialized, the Dbc.dup method throws an exception that encapsulates EINVAL.

Otherwise, the Dbc.dup method throws an exception that encapsulates a non-zero error value on failure.

# Errors

The Dbc.dup method may fail and throw an exception encapsulating a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

  The cursor argument was created using the Db.DB_WRITECURSOR flag in the Berkeley DB Concurrent Data Store product.

The Dbc.dup method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods. If a catastrophic error has occurred, the Dbc.dup method may fail and throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.

# Class

Dbc

# See Also

Dbc.close, Dbc.count, Dbc.del, Dbc.dup, Dbc.get, Dbc.pget, and Dbc.put.`

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