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Berkeley DB: db_create
db_create
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#include <db.h>
typedef struct __db DB;
int
db_create(DB **dbp, DB_ENV *dbenv, u_int32_t flags);
Description: db_create
The DB handle is the handle for a Berkeley DB database, which may or
may not be part of a database environment.
DB handles are free-threaded if the DB_THREAD flag is
specified to the DB->open method when the database is opened or if the
database environment in which the database is opened is free-threaded.
The handle should not be closed while any other handle that refers to
the database is in use; for example, database handles must 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. Once the DB->close, DB->remove, or
DB->rename methods are called, the handle may not be accessed again,
regardless of the method's return.
The db_create method creates a DB structure that is the
handle for a Berkeley DB database. Calling the DB->close,
DB->remove or DB->rename methods will discard the returned
handle.
The DB handle contains a special field, "app_private", which is
declared as type "void *". This field is provided for the use of the
application program. It is initialized to NULL and is not further used
by Berkeley DB in any way.
The db_create method
returns a non-zero error value on failure
and 0 on success.
Parameters
- dbp
- The dbp parameter references the memory into which the returned
structure pointer is stored.
- dbenv
- If the dbenv parameter is NULL, the database is standalone; that
is, it is not part of any Berkeley DB environment.
If the dbenv parameter is not NULL, the database is created
within the specified Berkeley DB environment. The database access methods
automatically make calls to the other subsystems in Berkeley DB, based on the
enclosing environment. For example, if the environment has been
configured to use locking, the access methods will automatically acquire
the correct locks when reading and writing pages of the database.
- flags
- The flags parameter must be set to 0 or
the following value:
- DB_XA_CREATE
- Instead of creating a standalone database, create a database intended
to be accessed via applications running under an X/Open conformant
Transaction Manager. The database will be opened in the environment
specified by the OPENINFO parameter of the GROUPS section of the
ubbconfig file. See the XA
Introduction section in the Berkeley DB Reference Guide for more information.
Errors
The db_create method
may fail and return one of the following non-zero errors:
- EINVAL
- An
invalid flag value or parameter was specified.
Class
DB
See Also
Databases and Related Methods
Copyright (c) 1996-2004 Sleepycat Software, Inc. - All rights reserved.
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