In addition to Oracle export utility modes,
the export utility enables the user to specify
runtime parameters interactively, on the
command line, or defined in a parameter file
(PARFILE).
Also, see my notes on
Oracle
tablespace exports. abd
export performance tuning.
The export command options include:
?
buffer - Specifies
the size, in bytes, of the buffer used to
fetch the rows. If 0 is specified, only
one row is fetched at a time. This
parameter only applies to conventional (non
direct) exports.
?
compress - When
?Y?, export will mark the table to be loaded
as one extent for the import utility. If
?N?, the current storage options defined for
the table will be used. Although this
option is only implemented on import, it can
only be specified on export.
?
consistent - [N]
Specifies the set transaction read only
statement for export, ensuring data
consistency. This option should be set
to ?Y? if activity is anticipated while the
exp
command is executing. If ?Y? is set, confirm
that there is sufficient undo segment space to
avoid the export session getting the ORA-1555
Snapshot too old error.
?
constraints - [Y]
Specifies whether table constraints should be
exported with table data.
?
direct - [N]
Determines whether to use direct or
conventional path export. Direct path
exports bypass the SQL command, thereby
enhancing performance.
?
feedback - [0]
Determines how often feedback is displayed.
A value of feedback=n displays a dot
for every n rows processed. The
display shows all tables exported not
individual ones. From the output below,
each of the 20 dots represent 50,000 rows,
totaling 1 million rows for the table.
About to export specified tables via Direct
Path ...
. .
exporting table
TABLE_WITH_ONE_MILLION_ROWS
....................
1000000 rows exported
?
file - The name of
the export file. Multiple files can be listed,
separated by commas. When export fills
the
filesize, it will begin writing to the
next file in the list.
?
filesize - The
maximum file size, specified in bytes.
?
flashback_scn - The system change number (SCN) that export
uses to enable flashback.
?
flashback_time - Export will discover the SCN that is closest
to the specified time. This SCN is used
to enable flashback.
?
full - The entire
database is exported.
?
grants - [Y]
Specifies object grants to export.
?
help - Shows
command line options for export.
?
indexes - [Y]
Determines whether index definitions are
exported. The index data is never
exported.
?
log - The
filename used by export to write messages.
The same messages that appear on the screen
are written to this file:
Export done in WE8MSWIN1252 character set and
AL16UTF16 NCHAR character set
About to export specified tables via Direct
Path ...
. . exporting table
TABLE_WITH_ONE_MILLION_ROWS
1000000 rows exported
Export terminated successfully without
warnings.
?
object_consistent - [N] Specifies whether export uses SET
TRANSACTION READ ONLY to ensure that the data
being exported is consistent.
?
owner - Only the
owner's objects will be exported.
?
parfile - The name
of the file that contains the export parameter
options. This file can be used instead
of specifying all the options on the command
line for each export.
?
query - Allows a subset of rows from a table to be
exported, based on a SQL where clause
(discussed later in this chapter).
?
recordlength - Specifies the length of the file record in
bytes. This parameter affects the amount
of data that accumulates before it is written
to disk. If not specified, this
parameter defaults to the value specific to
that platform. The highest value is
64KB.
?
resumable - [N]
Enables and disables resumable space
allocation. When ?Y?, the parameters
resumable_name and resumable_timeout
are utilized.
?
resumable_name - User defined string that helps identify a
resumable statement that has been suspended.
This parameter is ignored unless resumable
= Y.
?
resumable_timeout - [7200 seconds] The time period in which an
export error must be fixed. This
parameter is ignored unless resumable = Y.
?
rows - [Y]
Indicates whether or not the table rows should
be exported.
?
statistics - [ESTIMATE] Indicates the level of statistics
generated when the data is imported.
Other options include COMPUTE and NONE.
?
tables - Indicates
that the type of export is table-mode and
lists the tables to be exported. Table
partitions and sub partitions can also be
specified.
?
tablespaces - Indicates that the type of export is
tablespace-mode, in which all tables assigned
to the listed tablespaces will be exported.
This option requires the EXP_FULL_DATABASE
role.
?
transport_tablespace - [N] Enables the export of metadata needed
for transportable tablespaces.
?
triggers - [Y]
Indicates whether triggers defined on export
tables will also be exported.
?
tts_full_check - [FALSE] When TRUE, export will verify that
when creating a transportable tablespace, a
consistent set of objects is exported.
?
userid - Specifies
the userid/password of the user performing the
export.
?
volsize - Specifies the maximum number of bytes in an
export file on each tape volume.
The functionality of the export utility has
been significantly enhanced in recent versions
of Oracle. To check which options are
available in any release use:
exp help=y
See here for tips on
tuning a data pump export for fast
performance.
Other Related
Oracle Export Articles:
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