Oracle Database Administration: The Essential Refe

Export Parameters

The following is a description of the Export parameters that may be specified, either on a command line or in a parameter file:

BUFFER=buffersize

Specifies the size, in bytes, of the buffer used to fetch rows. This parameter determines the maximum number of rows in an array fetched by Export as:

rows = buffer / maximum_row_size

If you specify zero, Export fetches one row at a time. Tables with LONG, LOB, BFILE, REF, ROWID, or type columns are always fetched one row at a time. BUFFER applies only to conventional path export, and has no effect on a direct path export. The default is operating system dependent.

COMPRESS={Y | N}

Specifies how Export manages the initial extent for table data. The default, COMPRESS=Y, causes Export to write a CREATE object statement for use in a subsequent import that will cause the object to be created with a single initial extent. If COMPRESS=N is specified, Export uses the current storage parameters, including the values of the INITIAL extent size and the NEXT extent size.

CONSISTENT={Y | N}

Specifies whether Export uses the SET TRANSACTION READ ONLY statement to ensure that the data seen by Export is consistent to a single point in time and does not change during the execution of the EXP command. You should specify CONSISTENT=Y when you anticipate that other applications will update the database after an export has started. The default is CONSISTENT=N.

CONSTRAINTS={Y | N}

Specifies whether the Export utility exports table constraints. The ...