These tools are used to transfer data from one oracle database to another oracledatabase. You Export tool to export data from source database, and Import tool to loaddata into the target database. When you export tables from source database export toolwill extracts the tables and puts it into the dump file. This dump file is transferred tothe target database. At the target database the Import tool will copy the data fromdump file to the target database.

From Ver. 10g Oracle is recommending to use Data Pump Export and Import tools,which are enhanced versions of original Export and Import tools.

The export dump file contains objects in the following order:

1. Type definitions2. Table definitions3. Table data4. Table indexes5. Integrity constraints, views, procedures, and triggers6. Bitmap, function-based, and domain indexes

When you import the tables the import tool will perform the actions in the followingorder, new tables are created, data is imported and indexes are built, triggers areimported, integrity constraints are enabled on the new tables, and any bitmap,function-based, and/or domain indexes are built. This sequence prevents data frombeing rejected due to the order in which tables are imported. This sequence alsoprevents redundant triggers from firing twice on the same data

Invoking Export and Import

You can run Export and Import tool in two modes

Command Line Mode

Interactive Mode

When you just type exp or imp at o/s prompt it will run in interactive mode i.e. thesetools will prompt you for all the necessary input. If you supply command linearguments when calling exp or imp then it will run in command line mode

Command Line Parameters of Export tool

You can control how Export runs by entering the EXP command followedby various arguments. To specify parameters, you use keywords:

Format: EXP KEYWORD=value or KEYWORD=(value1,value2,...,valueN)

Example: EXP SCOTT/TIGER GRANTS=Y TABLES=(EMP,DEPT,MGR)

or TABLES=(T1:P1,T1:P2), if T1 is partitioned table

Keyword Description (Default)

--------------------------------------------------------------

USERID username/password

BUFFER size of data buffer

FILE output files (EXPDAT.DMP)

COMPRESS import into one extent (Y)

GRANTS export grants (Y)

INDEXES export indexes (Y)

DIRECT direct path (N)

LOG log file of screen output

ROWS export data rows (Y)

CONSISTENT cross-table consistency(N)

FULL export entire file (N)

OWNER list of owner usernames

TABLES list of table names

RECORDLENGTH length of IO record

INCTYPE incremental export type

RECORD track incr. export (Y)

TRIGGERS export triggers (Y)

STATISTICS analyze objects (ESTIMATE)

PARFILE parameter filename

CONSTRAINTS export constraints (Y)OBJECT_CONSISTENT transaction set to read only during object export (N)

FEEDBACK display progress every x rows (0)

FILESIZE maximum size of each dump file

FLASHBACK_SCN SCN used to set session snapshot back to

FLASHBACK_TIME time used to get the SCN closest to the specified time

QUERY select clause used to export a subset of a table

RESUMABLE suspend when a space related error is encountered(N)

RESUMABLE_NAME text string used to identify resumable statement

RESUMABLE_TIMEOUT wait time for RESUMABLE

TTS_FULL_CHECK perform full or partial dependency check for TTS

TABLESPACES list of tablespaces to export

TRANSPORT_TABLESPACE export transportable tablespace metadata (N)

TEMPLATE template name which invokes iAS mode export

The Export and Import tools support four modes of operation

FULL :Exports all the objects in all schemasOWNER :Exports objects only belonging to the given OWNERTABLES :Exports Individual TablesTABLESPACE :Export all objects located in a given TABLESPACE.

Example of Exporting Full Database

The following example shows how to export full database

$exp USERID=scott/tiger FULL=y FILE=myfull.dmp

In the above command, FILE option specifies the name of the dumpfile, FULL option specifies that you want to export the full database, USERID optionspecifies the user account to connect to the database. Note, to perform full export theuser should have DBA or EXP_FULL_DATABASE privilege.

Example of Exporting Schemas

To export Objects stored in a particular schemas you can run export utility with thefollowing arguments

$exp USERID=scott/tiger OWNER=(SCOTT,ALI)FILE=exp_own.dmp

The above command will export all the objects stored in SCOTT and ALI’s schema.

Exporting Individual Tables

To export individual tables give the following command

$exp USERID=scott/tiger TABLES=(scott.emp,scott.sales)FILE=exp_tab.dmp

This will export scott’s emp and sales tables.

Exporting Consistent Image of the tables

If you include CONSISTENT=Y option in export command argument then, Exportutility will export a consistent image of the table i.e. the changes which are done to thetable during export operation will not be exported.

Using Import Utility

Objects exported by export utility can only be imported by Import utility. Importutility can run in Interactive mode or command line mode.

You can let Import prompt you for parameters by entering the IMP commandfollowed by your username/password:

Example: IMP SCOTT/TIGER

Or, you can control how Import runs by entering the IMP command followed

by various arguments. To specify parameters, you use keywords:

Format: IMP KEYWORD=value orKEYWORD=(value1,value2,...,valueN)

Example: IMP SCOTT/TIGER IGNORE=Y TABLES=(EMP,DEPT)FULL=N

or TABLES=(T1:P1,T1:P2), if T1 ispartitioned table

USERID must be the first parameter on the command line.

Keyword Description (Default)USERID username/passwordBUFFER size of data bufferFILE input files (EXPDAT.DMP)SHOW just list file contents (N)IGNORE ignore create errors (N)GRANTS import grants (Y)INDEXES import indexes (Y)ROWS import data rows (Y)LOG log file of screen outputFULL import entire file (N)FROMUSER list of owner usernamesTOUSER list of usernamesTABLES list of table namesRECORDLENGTH length of IO recordINCTYPE incremental import typeCOMMIT commit array insert (N)PARFILE parameter filenameCONSTRAINTS import constraints (Y)DESTROY overwrite tablespace data file (N)INDEXFILE write table/index info to specified fileSKIP_UNUSABLE_INDEXES skip maintenance of unusable indexes (N)FEEDBACK display progress every x rows(0)

TOID_NOVALIDATE skip validation of specified type idsFILESIZE maximum size of each dump fileSTATISTICS import precomputed statistics (always)RESUMABLE suspend when a space related error is encountered(N)RESUMABLE_NAME text string used to identify resumable statementRESUMABLE_TIMEOUT wait time for RESUMABLECOMPILE compile procedures, packages, and functions (Y)STREAMS_CONFIGURATION import streams general metadata (Y)STREAMS_INSTANITATION import streams instantiation metadata (N)

Example Importing Individual Tables

To import individual tables from a full database export dump file give the followingcommand

$imp scott/tiger FILE=myfullexp.dmpFROMUSER=scott TABLES=(emp,dept)

This command will import only emp, dept tables into Scott user and you will get aoutput similar to as shown below

Export file created by EXPORT:V10.00.00 via conventional path

import done in WE8DEC character set and AL16UTF16 NCHAR character set

. importing SCOTT's objects into SCOTT

. . importing table "DEPT" 4 rows imported

. . importing table "EMP" 14 rows imported

Import terminated successfully without warnings.

Example, Importing Tables of One User account into another User account

For example, suppose Ali has exported tables into a dump file mytables.dmp. NowScott wants to import these tables. To achieve this Scott will give the followingimport command

$imp scott/tiger FILE=mytables.dmpFROMUSER=ali TOUSER=scott

Then import utility will give a warning that tables in the dump file was exported byuser Ali and not you and then proceed.

Example Importing Tables Using Pattern Matching

Suppose you want to import all tables from a dump file whose name matches aparticular pattern. To do so, use “%” wild character in TABLES option. For example,the following command will import all tables whose names starts with alphabet “e”and those tables whose name contains alphabet “d”

$imp scott/tiger FILE=myfullexp.dmpFROMUSER=scott TABLES=(a%,%d%)

Migrating a Database across platforms.

The Export and Import utilities are the only method that Oracle supports for movingan existing Oracle database from one hardware platform to another. This includesmoving between UNIX and NT systems and also moving between two NT systemsrunning on different platforms.

The following steps present a general overview of how to move a database betweenplatforms.

1. As a DBA user, issue the following SQL query to get the exact name of all tablespaces. You willneed this information later in the process.

SQL> SELECT tablespace_name FROM dba_tablespaces;2. As a DBA user, perform a full export from the source database, for example:

> exp system/manager FULL=y FILE=myfullexp.dmp3. Move the dump file to the target database server. If you use FTP, be sure to copy it in binary

format (by entering binary at the FTP prompt) to avoid file corruption.

4. Create a database on the target server.

5. Before importing the dump file, you must first create your tablespaces, using the informationobtained in Step 1. Otherwise, the import will create the corresponding datafiles in the same filestructure as at the source database, which may not be compatible with the file structure on thetarget system.

6. As a DBA user, perform a full import with the IGNORE parameter enabled:

> imp system/manager FULL=y IGNORE=yFILE=myfullexp.dmp

Using IGNORE=y instructs Oracle to ignore any creation errors during the import and permit the importto complete.

7. Perform a full backup of your new database.

7.8. Using Data Pump Export Utility8.9. To Use Data Pump, DBA has to create a directory in Server Machine

and create a Directory Object in the database mapping to the directory createdin the file system.

9.10. The following example creates a directory in the filesystem and creates adirectory object in the database and grants privileges on the Directory Object tothe SCOTT user.

10.11. $mkdir my_dump_dir$sqlplusEnter User:/ as sysdbaSQL>create directory data_pump_dir as‘/u01/oracle/my_dump_dir’;

11.12. Now grant access on this directory object to SCOTT user12.13. SQL> grant read,write on

directory data_pump_dir to scott;13.14. Example of Exporting a Full Database14.15. To Export Full Database, give the following command15.16. $expdp scott/tiger FULL=y

DIRECTORY=data_pump_dir DUMPFILE=full.dmpLOGFILE=myfullexp.log JOB_NAME=myfullJob

16.17. The above command will export the full database and it will create thedump file full.dmp in the directory on the server /u01/oracle/my_dump_dir

17.18. In some cases where the Database is in Terabytes the above commandwill not feasible since the dump file size will be larger than the operatingsystem limit, and hence export will fail. In this situation you can create multipledump files by typing the following command

18.19. $expdp scott/tiger FULL=yDIRECTORY=data_pump_dir DUMPFILE=full%U.dmp

FILESIZE=5G LOGFILE=myfullexp.logJOB_NAME=myfullJob

19.20. This will create multiple dump files named full01.dmp, full02.dmp,full03.dmp and so on. The FILESIZE parameter specifies how much larger thedump file should be.

21.Example of Exporting a Schema22.To export all the objects of SCOTT’S schema you can run the following export

data pump command.

23.$expdp scott/tigerDIRECTORY=data_pump_dir DUMPFILE=scott_schema.dmp

SCHEMAS=SCOTT24.You can omit SCHEMAS since the default mode of Data Pump export is

SCHEMAS only.25.If you want to export objects of multiple schemas you can specify the following

command26.$expdp scott/tiger

DIRECTORY=data_pump_dir DUMPFILE=scott_schema.dmpSCHEMAS=SCOTT,HR,ALI

27.Exporting Individual Tables using Data Pump Export28.You can use Data Pump Export utility to export individual tables. The

following example shows the syntax to export tables29.$expdp hr/hr DIRECTORY=dpump_dir1 DUMPFILE=tables.dmp30. TABLES=employees,jobs,departments31.32.Exporting Tables located in a Tablespace33.If you want to export tables located in a particular tablespace you can type the

following command34.35.$expdp hr/hr DIRECTORY=dpump_dir1 DUMPFILE=tbs.dmp36.TABLESPACES=tbs_4, tbs_5, tbs_637.38.The above will export all the objects located in tbs_4,tbs_5,tbs_639.40.Excluding and Including Objects during Export41.You can exclude objects while performing a export by using EXCLUDE option

of Data Pump utility. For example you are exporting a schema and don’t wantto export tables whose name starts with “A” then you can type the followingcommand

42.$expdp scott/tigerDIRECTORY=data_pump_dir DUMPFILE=scott_schema.dmp

SCHEMAS=SCOTT EXCLUDE=TABLE:”like ‘A%’”43.Then all tables in Scott’s Schema whose name starts with “A “ will not be

exported.44.Similarly you can also INCLUDE option to only export certain objects like this45.$expdp scott/tiger

DIRECTORY=data_pump_dir DUMPFILE=scott_schema.dmpSCHEMAS=SCOTT INCLUDE=TABLE:”like ‘A%’”

46.This is opposite of EXCLUDE option i.e. it will export only those tables ofScott’s schema whose name starts with “A”

47.Similarly you can also exclude INDEXES, CONSTRAINTS, GRANTS,USER, SCHEMA

48.Using Query to Filter Rows during Export49.You can use QUERY option to export only required rows. For Example, the

following will export only those rows ofemployees tables whose salary isabove 10000 and whose dept id is 10.

50. expdp hr/hr QUERY=emp:'"WHERE dept_id > 10 AND sal > 10000"'51. NOLOGFILE=y DIRECTORY=dpump_dir1 DUMPFILE=exp1.dmp52.53.Suspending and Resuming Export Jobs (Attaching and Re-Attaching to

the Jobs)54.You can suspend running export jobs and later on resume these jobs or kill

these jobs using Data Pump Export. You can start a job in one client machineand then, if because of some work, you can suspend it. Afterwards when yourwork has been finished you can continue the job from the same client, whereyou stopped the job, or you can restart the job from another client machine.

55.For Example, suppose a DBA starts a full database export by typing thefollowing command at one client machine CLNT1 by typing the followingcommand

56.$expdp scott/tiger@mydb FULL=yDIRECTORY=data_pump_dir

DUMPFILE=full.dmp LOGFILE=myfullexp.logJOB_NAME=myfullJob

57.After some time, the DBA wants to stop this job temporarily. Then he pressesCTRL+C to enter into interactive mode. Then he will get the Export> promptwhere he can type interactive commands

58.Now he wants to stop this export job so he will type the following command59.Export> STOP_JOB=IMMEDIATE

Are you sure you wish to stop this job ([y]/n): y60.The job is placed in a stopped state and exits the client.61.After finishing his other work, the DBA wants to resume the export job and the client

machine from where he actually started the job is locked because, the user has lockedhis/her cabin. So now the DBA will go to another client machine and he reattach to thejob by typing the following command

62.$expdp hr/hr@mydb ATTACH=myfulljob63.After the job status is displayed, he can issue the CONTINUE_CLIENT command to resume

logging mode and restart themyfulljob job.64.Export> CONTINUE_CLIENT65.A message is displayed that the job has been reopened, and processing status is output to

the client.66.Note: After reattaching to the Job a DBA can also kill the job by typing KILL_JOB, if he

doesn’t want to continue with the export job.

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