Oracle 10g Data Pump Say good bye to exp and imp (or not)!

1. Oracle 10g Data PumpSay good bye to exp and imp (or not)! 2006/02/23 Simon Pane

2. Agenda • Data Pump Overview • Using Data Pump • Demonstration • Data Pump Test Cases

3. Data Pump Overview

4. What is Data Pump? • A replacement of the traditional export/import utilities? • The evolution of the traditional export/import utilities? • A completely new 10g utility serving a similar yet slightly different purpose?

5. Other Options for Moving Data • Traditional Export and Import • Pros • Easy to use – most DBAs have years of experience using these utilities • Versatile – various options available; can specify what to include • Platform independent • Serial output • Cons • Comparatively slow • Can be network intensive • Non-interruptible / resumable • Limited filtering options (for example, can exclude just VIEWS) • Limited remapping options (i.e. from one tablespace to another)

6. Other Options for Moving Data • Transportable Tablespaces • Pros • Undoubtedly the fastest way to move data • Can use the traditional exp/imp or Data Pump to move meta-data • Cross-platform support if the platform byte-order is the same • Cons • Tablespaces must be made read-only • Not selective (must move the entire tablespace) • Flashback is not possible (tablespace is read only when copied) • No physical reorganization is performed • Datafile sizes remain constant • Must use RMAN to convert the datafile if migrating to a platform with a different byte-order (check V$TRANSPORTABLE_PLATFORM)

7. Other Options Used Less Frequently • Extraction to a flat file and loading using SQL Loader • Direct copy using database links (SQL Plus COPY command) • Oracle Streams • 3rd Party data ETL or reorg tools

8. Top 10 Reasons to Love DataPump • Similar look and feel to the old exp/imp • Can filter on the full range of object types • Can re-map datafiles and or tablespaces on import • Estimates the export file size (space needed) • Parallelizable • Significantly faster than the traditional exp/imp • PL/SQL Interface – programmable • A file is not actually required - can import through a network link • Track in v$session_longops • Resumable (interruptible and restartable)

9. Top 10 Reasons Not to Love Data Pump • Still generates redo (unlike direct path inserts) • Aggregation of exported data is not possible (sort only) • Performance on the server • Harder to tell what it’s doing at any given time • No equivalent to the STATISTICS option • Cannot be used with sequential media such as tapes and pipes (not read/written serially) • Only accesses files on the server, never the client • Oracle directories are required in the DB to access the files • Does not support COMMIT on imp or CONSISTENT on exp • If constraints are violated on import, the load is discontinued

10. Operation Fundamentals • Export/Import • These utilities would basically connect to the Oracle database via Oracle NET and run queries or DDL/DML • Processing of returned results and I/O operations were done on the client • Data Pump • The executables call PL/SQL APIs • Therefore processing is done on the database server • This can be an advantage or a disadvantage depending on the situation • “Self-Tuning”: no longer need to use BUFFER or RECORDSET

11. Export Operation Network Database Server Client Machine exp.exe Oracle Database Export File(s)

12. Data Pump Export Operation Network Database Server Client Machine expdp.exe Oracle Database Export File(s)

13. Key Differences • Dump and log files are on the server, not the client • Must have a DIRECTORY created in the Oracle database for I/O • Permissions for the userid connecting to the instance, not the schemas being exported or imported • Canceling the client process does not stop the job • Doesn’t automatically overwrite dump file if it already exists – returns an error instead • Parameters (command line) are reported in the log file • Exported objects order based on table size (descending) instead of alphabetically

14. Multiple Interfaces • Command line utilities expdb and impdb • Similar to the familiar exp and imp in usage • Use HELP=Y for a list of commands • Oracle documentation provides a comparison table to exp/imp • Enterprise Manager • PL/SQL • Can be used independently but is difficult • All of these call the DBMS_DATAPUMP API • Uses Oracle Advanced Queuing • Uses DBMS_METADATA

15. Unload Mechanisms • Data Pump automatically chooses to unload data either using: • Direct path • External Tables (new driver called ORACLE_DATAPUMP) • Same “External Tables” mechanism that was introduced in Oracle9i • When will it use External tables: • When parallelism can be used • When the table contains a complex data type or structure that prevents direct path unloads • A lot of tables fall under this situation – see Oracle documentation for a complete list • It doesn’t really matter to us which method is used

16. Multiple Processes • Master Control Process • Spawns worker processes • Populates the master control table and log file • The master control table can be queried to track the job’s process • At the end of an export, the master control table is written to the dump file and dropped from the database • Worker Processes • Performs the loading/unloading • Number of processes depends on the degree of parallelism (the PARALLEL option)

17. Detaching and Re-Attaching • Issuing “Ctrl-C” from the data pump import will detach • Import is running on the server so it will continue • Brings you into “interactive-command” mode • To re-attach, run impdp with the ATTACH= option • Example: impdp userid=system/oracle attach=JOB_01 • Brings you back into “interactive-command” mode

18. New Views • DBA_DATAPUMP_JOBS and USER_DATABASE_JOBS • Identify all jobs regardless of their state • Identify any master tables not associated with an active job • DBA_DATAPUMP_SESSIONS • Identify user sessions that are attached to a job • Data pump sessions populate v$session_longops • Documentation says that it is 100% accurate for imports but testing proves otherwise!!!

19. Security Considerations • Still uses the EXP_FULL_DATABASE and IMP_FULL_DATABASE • A privileged user will have these two roles • A privileged user can: • Export/import objects owned by other schemas • Export non-schema objects (metadata) • Attach to, monitor, and control jobs initiated by others • Perform schema, datafile, and tablespace remapping • Similar to the traditional export/import • Supports label security • If exporting user has the EXEMPT ACCESS POLICY role

20. Object Statistics • From Oracle documentation regarding data pump exports: • “A parameter comparable to STATISTICS is not needed. Statistics are always saved for tables.” • From Oracle documentation regarding data pump imports: • “A parameter comparable to STATISTICS is not needed. If the source table has statistics, they are imported.”

21. Other Random Points • Can still use a parameter file and the PARFILE command line option • Fully supports Automatic Storage Management (ASM) • Can still flashback to a specified time or SCN • Can still extract (or backup) DDL (meta data) • Using the SQLFILE option instead of the traditional INDEXFILE or SHOW options • Full support of LOBS

22. Using Data Pump

23. Oracle Directory Objects • Must first create an Oracle directory object and give the user who will be performing the Data Pump activities permission to use it (or rely on defaults): SQL> create or replace directory dpump_demo as 'C:\temp'; Directory created. SQL> grant read,write on directory dpump_demo to simon; Grant succeeded. SQL>

24. Key Data Pump Export Parameters • CONTENT={ALL | DATA_ONLY | METADATA_ONLY} • DIRECTORY=directory_object (default=DATA_PUMP_DIR) • DUMPFILE=[directory_object:]file_name [,…] • ESTIMATE={BLOCKS | STATISTICS} • ESTIMATE_ONLY={Y | N} • EXCLUDE=object_type[:name_clause] [,…] • FILESIZE=integer[B | K | M |G] (default=unlimited) • FLASHBACK_SCN=scn_value • FLASHBACK_TIME=“TO_TIMESTAMP(time_value)” • FULL={Y | N} • INCLUDE=object_type[:name_clause] [,…] • JOBNAME=jobname_string

25. Key Data Pump Export Parameters • LOGFILE=[directory_object:]file_name • NOLOGFILE={Y | N} • PARALLEL=integer (default=1) • QUERY=[schema.][table_name:]query_clause • SCHEMAS=schema_name [,…] • TABLES=[schema_name.]table_name[:partition_name] [,…] • TABLESPACES=tablespace_name [,…]

26. Data Pump Export Parameter Samples • Multiple dump files using a substitution variable (%U): • DUMPFILE=DP_DIR1:SCOTT_20060223_%U.dmp • Excluding indexes that start with “EMP”: • EXCLUDE=INDEX:“LIKE ‘EMP%’” • Excluding the SCOTT schema from a FULL export: • EXCLUDE=SCHEMA:“=‘SCOTT’” • Mimicking the traditional CONSITENT parameter: • FLASHBACK_TIME=“TO_TIMESTAMP” • Exporting only TABLES, FUNCTIONS and VIEWS: • INCLUDE=TABLE,FUNCTION,VIEW • Using a query clause • QUERY=emp:‘“WHERE salary > 100000”’

27. Key Data Pump Import Parameters • CONTENT={ALL | DATA_ONLY | METADATA_ONLY} • DIRECTORY=directory_object (default=DATA_PUMP_DIR) • DUMPFILE=[directory_object:]file_name [,…] • EXCLUDE=object_type[:name_clause] [,…] • FULL={Y | N} • INCLUDE=object_type[:name_clause] [,…] • JOBNAME=jobname_string • LOGFILE=[directory_object:]file_name • NOLOGFILE={Y | N} • PARALLEL=integer (default=1) • QUERY=[schema.][table_name:]query_clause

28. Key Data Pump Import Parameters • REMAP_DATAFILE=source_datafile:target_datafile • REMAP_SCHEMA=source_schema:target_schema • REMAP_TABLESPACE=source_tablespace:target_tablespace • REUSE_DATAFILES={Y | N} • SCHEMAS=schema_name [,…] • SKIP_UNUSABLE_INDEXES={Y | N} • SQLFILE=[directory_object:]file_name • TABLE_EXISTS_ACTION={SKIP|APPEND|TRUNCATE|REPLACE} • TABLES=[schema_name.]table_name[:partition_name] [,…] • TABLESPACES=tablespace_name [,…]

29. Interactive Mode Commands • ADD_FILE=[directory_object:]file_name [,…] • CONTINUE_CLIENT • EXIT_CLIENT • FILESIZE=number • KILL_JOB • PARALLEL=integer • START_JOB • STATUS • STOP_JOB

30. Demonstration

31. Exporting and Importing Sample Schemas • expdp system/oracle@ORA1020 dumpfile=scott.dmp schemas=scott • impdp system/oracle@ORA1020 dumpfile=scott.dmp schemas=SCOTT remap_schema=SCOTT:LARRY • expdb system/oracle@ORA1020 dumpfile=larry.dmp schemas=larry • SELECT * FROM DBA_DATAPUMP_JOBS;

32. Using Interactive Mode • Ctrl-C to detach from the current export • Export> status • Export> stop_job • expdp system/oracle@ORA1020 attach=SYS_EXPORT_SCHEMA_01 • Export> start_job • Export> exit_client

33. Data Pump Test Cases

34. Test Scenario #1 • Generated sample SIEBEL data • Brushed off the dust on some old SIEBEL data population scripts (circa 07/2000) • Designed for SIEBEL 6 on Oracle 8.1.6 • Actual data is not important • Schema objects • Tables: 218 (many empty tables) • Indexes: 1180 (SIEBEL is a heavily indexed application) • Schema size (from DBA_SEGMENTS) • Tables: 1255MB • Indexes: 148MB

35. Export Performance Test Criteria • All work performed on laptop C681 • SGA remains constant • SGA_TARGET=0 • SGA_MAX_SIZE=256MB • BUFFER CACHE=152MB • SHARED_POOL=60MB • Mostly default parameters • Not monitoring CPU utilization • Performed 4 runs • Disregarded results from 1st run and averaged the other 3

36. Export Scripts • EXP • sqlplus -s system/oracle @timestamp.sql > exp.log • exp.exe userid=system/oracle@ORA1020 file=SIEBEL.dmp log=SIEBEL.log owner='SIEBEL' • sqlplus -s system/oracle @timestamp.sql >> exp.log • EXPDP • erase SIEBEL.dmp • sqlplus -s system/oracle @timestamp.sql > expdp.log • expdp.exe userid=system/oracle@ORA1020 dumpfile=SIEBEL.dmp logfile=SIEBEL.log schemas='SIEBEL' directory=test_dir • sqlplus -s system/oracle @timestamp.sql >> expdp.log

37. Export Performance Test Results

38. Import Scripts • IMP • sqlplus -s system/oracle @timestamp.sql > exp.log • imp.exe userid=system/oracle@ORA1020 file=SIEBEL.dmp log=SIEBEL.log fromuser='SIEBEL' touser='SCOTT' commit=y • sqlplus -s system/oracle @timestamp.sql >> exp.log • IMPDP • sqlplus -s system/oracle @timestamp.sql > expdp.log • impdp.exe userid=system/oracle@ORA1020 dumpfile=SIEBEL.dmp logfile=SIEBEL.log schemas='SIEBEL' directory=test_dir remap_schema=SIEBEL:SCOTT remap_tablespace=TOOLS:SCOTT_DATA • sqlplus -s system/oracle @timestamp.sql >> expdp.log

39. Import Performance Test Results • Database was in ARCHIVELOG mode • Destination tablespace and archived log destination were both on ASM drives • Machine performance was degraded much more by impdb import • No import tuning performed (only COMMIT=Y)

40. Test Scenario #2 • Data taken from an actual CGI internal application • Schema objects • Tables: 22 • Indexes: 26 • Schema size (from DBA_SEGMENTS) • Tables: 300MB • Indexes: 101MB

41. Export Scripts • EXP • sqlplus -s system/oracle @timestamp.sql > exp.log • exp.exe userid=system/oracle@ORA1020 file=SCOTT.dmp log=SCOTT.log owner='SCOTT' • sqlplus -s system/oracle @timestamp.sql >> exp.log • EXPDP • erase SIEBEL.dmp • sqlplus -s system/oracle @timestamp.sql > expdp.log • expdp.exe userid=system/oracle@ORA1020 dumpfile=SCOTT.dmp logfile=SCOTT.log schemas='SCOTT' directory=test_dir • sqlplus -s system/oracle @timestamp.sql >> expdp.log

42. Export Performance Test Results

43. Import Scripts • IMP • sqlplus -s system/oracle @timestamp.sql > exp.log • imp.exe userid=system/oracle@ORA1020 file=SCOTT.dmp log=SCOTT.log fromuser='SCOTT' touser='LARRY' commit=y • sqlplus -s system/oracle @timestamp.sql >> exp.log • IMPDP • sqlplus -s system/oracle @timestamp.sql > expdp.log • impdp.exe userid=system/oracle@ORA1020 dumpfile=SCOTT.dmp logfile=SCOTT.log schemas='SCOTT' directory=test_dir remap_schema=SCOTT:LARRY remap_tablespace=SCOTT_DATA:LARRY_DATA • sqlplus -s system/oracle @timestamp.sql >> expdp.log

44. Import Performance Test Results • Database was in NOARCHIVELOG mode • Destination tablespace and archived log destination were both on ASM drives • No import tuning performed (only COMMIT=Y)

45. Conclusions

46. Conclusions • Data Pump is an exciting new Oracle 10g tool that provides many benefits over the traditional export and import utilities • Whether to use Data Pump, Transportable Tablespaces, or even the traditional exp/imp will depend on the situation • Since the command line interface is easy to use and so similar to the traditional exp/imp, DBAs and developers should spend the time to learn how to use it • Final thought: since Data Pump dump files and traditional export dump files are not compatible/interchangeable, should a new file extension be used??? (.dmp vs .dpd)

47. The End Comments, Questions ???