Transcript Data Pump - Glennb.us

CHAPTER 13
Data Pump
Data Pump
• Tool that replaces legacy exp/imp utilities
• Data Pump is a scalable, feature-rich utility that allows
you to extract objects and data from a database
• You can use the extract file as:
• Point in time backup of your database
• Efficiently copy large amounts of objects/data from one database
environment to another
• Extract SQL from the export file
• Partially extract specific objects or data from the export file
• Easily stop/suspend/restart operations
Data Pump Architectural Components
• expdp (Data Pump export utility)
• impdp (Data Pump import utility)
• DBMS_DATAPUMP PL/SQL package (Data Pump API)
• DBMS_METADATA PL/SQL package (Data Pump
Metadata API)
Data Pump Architecture
Steps Required to Export Data
1. Create a database-directory object that points to an
operating-system directory that you want to write/read
Data Pump files to/from.
2. Grant read, write on the directory to the database user
running the export.
3. From the operating-system prompt, run the expdp utility.
Creating a Database Directory
• Use CREATE DIRECTORY statement to create a
directory:
SQL> create directory dp_dir as '/oradump';
• View directory details:
SQL> select owner, directory_name, directory_path from
dba_directories;
Granting Access to the Directory
• As a privileged user, grant access to the directory to the
user who will be invoking expdp:
SQL> grant read, write on directory dp_dir to <user>;
Taking an Export
• From the operating system invoke expdp:
$ expdp darl/foo directory=dp_dir tables=inv
dumpfile=exp.dmp logfile=exp.log
Importing using Data Pump
• Similar to export, but using the import utility.
• Need to setup directory and access
1. Create a database-directory object that points to an
operating-system directory that you want to write/read
Data Pump files to/from.
2. Grant read, write on the directory to the database user
running the export or import.
3. From the operating system prompt, run the impdp
command.
Using Data Pump Interactive Command
Mode
• Allows you to interact with Data Pump from a command
line mode utility interface.
• There are two ways to get to the interactive commandmode prompt:
• Press Ctrl+C in a Data Pump job that you started via expdp or
impdp.
• Use the ATTACH parameter to attach to a currently running job
• Most useful commands: status, start_job, kill_job, parallel,
stop_job.
Attaching to a Running Job
• You can attach to a currently running Data Pump job to
view its status, stop/start it, and so on.
• Determine the job name:
SQL> select owner_name, operation, job_name, state from
dba_datapump_jobs;
• Use the ATTACH command line switch:
$ impdp darl/engdev attach=sys_import_schema_02
Stopping and Restarting a Job
• You can stop and restart a Data Pump job
• First attach to the job, then issue interactive commands:
$ impdp darl/foo attach=sys_import_table_01
Import> stop_job
Import> start_job
Terminating a Data Pump Job
• You might find yourself in a scenario where you have a
long running Data Pump job that appears to be hung.
• You want to kill the job as gracefully as possible.
• First attach to the job, then kill it:
Import> kill_job
Using a Parameter File
• Parameter files are useful for repeatability and consistency.
• Parameter files also make it easier to handle parameters that
use single and double quotes.
• Sometimes single and double quotes are mis-interpreted by the
OS when entered on the command line.
userid=darl/foo
directory=dp
dumpfile=invp.dmp
logfile=invp.log
tables=f_sales
$ impdp parfile=pfile.ctl
Estimating the Size of Export Jobs
• Sometimes it’s useful to estimate the size of a job before
starting it.
• Helps you get an idea how much disk space will be
required.
$ expdp dbauser/foo estimate_only=y full=y logfile=n
Listing the Contents of Dump Files
• Allows you to translate the contents of a dump file created by
expdp into SQL statements.
• Very handy for generating a copy of the SQL required to recreate an environment.
• Use the SQLFILE parameter:
$ impdp hr/hr DIRECTORY=dpump_dir1
DUMPFILE=expfull.dmp \
SQLFILE=dpump_dir2:expfull.sql
• In this mode, impdp doesn’t import anything, it only creates a
file that contains the SQL required to re-create objects within
the dump file.
Exporting and Importing Directly Across
the Network
• Powerful technique for copying environments.
• Efficient way to copy users and data from one database to
another.
1. Create users in target environment.
2. Create a database link
3. Create a directory object.
4. Run the impdp command using the NETWORK_LINK
5. parameter that points at the database link you created
in the prior step.
Transportable Tablespaces
• Powerful feature for copying large amounts of data from
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one environment to another.
Ensure tablespace is self-contained.
Make the tablespaces being transported read-only.
Use Data Pump to export the metadata for the
tablespaces being transported:
Copy the Data Pump export dump file to the destination
server.
Copy the datafile(s) to the destination database.
Import the metadata into the destination database.
Exporting Tablespace Metadata
• Sometimes it’s useful to capture tablespace information
and transfer it to a new database environment.
• Use a combination of FULL and
INCLUDE=TABLESPACE.
$ expdp darl/foo directory=dp dumpfile=phredstg.dmp
content=metadata_only full=y \
include=tablespace
Specifying Different Datafile Paths and
Names
• When you’re copying database environments, oftentimes the source
and target servers have different mount point names.
• You can rename the datafiles on the import using
REMAP_DATAFILE.
userid=darl/foo
directory=dp
dumpfile=phredstg.dmp
full=y
include=tablespace:"like 'TBSP%'"
remap_datafile="'/ora01/dbfile/O11R2/tbsp101.dbf':'/ora02/O11R2/tb1.d
bf'"
remap_datafile="'/ora01/dbfile/O11R2/tbsp201.dbf':'/ora02/O11R2/tb2.d
bf'"
remap_datafile="'/ora01/dbfile/O11R2/tbsp301.dbf':'/ora02/O11R2/tb3.d
bf'"
Changing Segment and Storage
Attributes
• You may have very different segment and storage
requirements when copying database environments.
• Use the TRANSFORM parameter to remove the segment
and storage attributes from being specified when
importing.
$ impdp darl/foo directory=dp dumpfile=inv.dmp
transform=segment_attributes:n
$ impdp darl/foo directory=dp dumpfile=inv.dmp
transform=storage:n
Importing into a Different Tablespace from
the Original
• You may want to export a user and when importing map
the old user to a new username and map the old
tablespaces associated with the user’s objects to new
tablespace names.
• Use REMAP_SCHEMA and REMAP_TABLESPACE
$ impdp darl/foo directory=dp dumpfile=rm.dmp
remap_schema=HEERA:CHAYA \
remap_tablespace=TBSP1:V_DATA tables=heera.ticket
Sophisticated Filtering Mechanisms
• Use the QUERY parameter to export or import subsets of data.
• Use the SAMPLE parameter to export a percentage of the rows
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in a table.
Use the CONTENT parameter to exclude or include data and
metadata.
Use the EXCLUDE parameter to specifically name items to be
excluded.
Use the INCLUDE parameter to name the items to be included
(thereby excluding other non-dependent items not included in
the list).
Use parameters like SCHEMA to specify that you only want a
subset of the database’s objects (those that belong to the
specified user or users).
Filtering via a Query
• Use this syntax to filter via a query:
QUERY = [schema.][table_name:] query_clause
• Example using a parameter file:
userid=darl/foo
directory=dp
dumpfile=inv.dmp
tables=inv,reg
query=inv:"WHERE inv_desc='Book'"
query=reg:"WHERE reg_id <=20"
Exporting a Percentage of the Data
• Doesn’t work well when exporting combinations of
parent/child tables, because the percentage doesn’t
enforce that parent rows match corresponding child rows.
• General syntax for exporting a percentage of data in a
table:
SAMPLE=[[schema_name.]table_name:]sample_percent
$ expdp darl/foo directory=dp tables=inv sample=10
dumpfile=inv.dmp
Excluding Objects from the Export File
• Use this general syntax to exclude objects from being
exported:
EXCLUDE=object_type[:name_clause] [, ...]
userid=darl/foo
directory=dp
dumpfile=inv.dmp
tables=inv
exclude=index:"LIKE 'INV%'"
Including Only Specific Objects in an
Export File
• Use INCLUDE to specify objects to be included.
directory=datapump
dumpfile=pl.dmp
include=function:"='ISDATE'",procedure:"='DEPTREE_FILL'"
Excluding Objects from Import
• Use EXCLUDE to exclude objects on import.
impdp darl/foo dumpfile=d.dmp directory=dp
exclude=TRIGGER,PROCEDURE
Including Objects in Import
• To only include objects on import, use INCLUDE:
userid=darl/foo
directory=dp
dumpfile=h.dmp
schemas=HEERA
include=table:"like 'A%'"
Creating a Consistent Export
• No consistent=y switch (like the old exp utility)
• Use flashback_scn or flashback_time
SQL> select current_scn from v$database;
$ expdp darl/foo directory=dp
flashback_scn=8400741902387
Importing When Objects Already Exist
• Use TABLE_EXISTS_ACTION to specify behavior if the
object already exists
• The TABLE_EXISTS_ACTION parameter takes the
following options:
• SKIP (default if not combined with CONTENT=DATA_ONLY)
• APPEND (default if combined with CONTENT=DATA_ONLY)
• REPLACE
• TRUNCATE
Renaming a Table
• Rename a table on import
• General syntax:
REMAP_TABLE=[schema.]old_tablename[.partition]:new_t
ablename
or
REMAP_TABLE=[schema.]old_tablename[:partition]:new_t
ablename
Remapping Data
• Allows you to obfuscate data on import.
• Some production data you may not want imported with
easily readable values.
• Create a PL/SQL function to obfuscate the data
$ impdp darl/foo directory=dp dumpfile=cust.dmp
tables=customers
remap_data=customers.last_name:obfus.obf
Cloning a User
• Use REMAP_SCHEMA to rename a user during import
$ impdp darl/foo directory=dp remap_schema=inv:inv_dw
dumpfile=inv.dmp
Miscellaneous Features
• Suppressing a Log File
• Using Parallelism
• Specifying Additional Dump Files
• Reusing Output File Names
• Creating a Daily DDL File
• Compressing Output
• Encrypting Data
Monitoring Data Pump Jobs
• Screen output
• Data Pump log file
• Database alert log
• Querying the status table
• Querying data-dictionary views
• Interactive command-mode status
• Using operating-system utilities’ process status ps
Data Pump Legacy Mode
• Enter old exp or imp parameter at the command line when
invoking Data Pump
• Data Pump automatically translates parameter into
parameters it understands
• Available starting with 11g R2
• Very handy feature if you’re familiar with the old exp/imp
utilities
Summary
• Data Pump is a flexible and powerful utility for taking point
in time backups and copying database environments.
• As a DBA, you should be proficient with this utility.
• Sophisticated object and data transfer filtering
parameters.
• Use Data Pump in legacy mode to view how the old
exp/imp parameters are translated into Data Pump
parameters.