Tuesday Jun 30, 2015

Some Data Pump issues:
+ DBMS_DATAPUMP Import via NETWORK_LINK fails
+ STATUS parameter giving bad performance

One of my dear Oracle ACS colleagues (Danke Thomas!) highlighted this issue to me as one of his lead customers hit this pitfall a week ago. . 

DBMS_DATAPUMP Import Over NETWORK_LINK fails with ORA-39126 / ORA-31600

Symptoms are: 

KUPW$WORKER.CONFIGURE_METADATA_UNLOAD [ESTIMATE_PHASE]
ORA-31600: invalid input value IN ('VIEWS_AS_TABLES/TABLE_DATA') for parameter VALUE in function SET_FILTER

This can be cured with the patch for bug19501000 -  but this patch can conflict with:Bug 18793246  EXPDP slow showing base object lookup during datapump export causes full table scan per object and therefore may require a merge patch - patch 21253883 is the one to go with in this case.

 .

Another issue Roy just came across:

Data Pump is giving bad performance in Oracle 12.1.0.2 when the STATUS parameter option is used on command line

Symptoms are: 

It looks like the routines we are using to get status are significantly slower in 12c than in 11g. On 11.2.0.4 a STATUS call of expdp/impdp runs in 0.2-0.3 seconds, but in 12.1.0.2 it takes 0.8-1.6 seconds. As a result the client falls behind on 12.1.0.2; it is taking about 0.5-0.8 seconds to put out each line in the logfile because it is getting the status each time. With over 9000 tables in a test that half a second really adds up. The result in this test case was that the data pump job completed in 35 minutes, but it took another 30-35 minutes to finish putting out messages on the client (the log file was already complete) and return control to the command line. This happens only when you use STATUS on the command line.

Recommendation is:  

Don't use the STATUS parameter on the expdp/impdp command line in Oracle 12.1.0.2 until the issue is fixed. This will be tracked under Bug 21123545.

--Mike 

Thursday Sep 04, 2014

OOW 2014 - Upgrade and Data Pump Talks

Oracle Open World (OOW) 2014 in San Francisco is coming ... just a few weeks to go ... everybody is in the prep phase for demos, presentations, labs etc. 

If you'd like to get in touch with us to discuss your upgrade and migration strategies please feel free to contact either Roy Swonger or myself directly. We'll be happy to assist you. And of course you are welcome to stop by at our combined Upgrade/DataPump booth at the demo grounds and visit one of our talks.

Our group is happy to deliver the following talks and labs:

How to Upgrade, Migrate, and Consolidate to Oracle Database 12c [CON7647]
Monday, Sep 29, 5:15 PM - 6:00 PM - Moscone South - 102

The most widely anticipated feature of Oracle Database 12c is now available, and you may be wondering just how you can move your current databases to pluggable databases in a multitenant architecture. Whether you are just starting to explore the world of pluggable databases or are planning a production upgrade in the near future to Oracle Database 12c, this presentation by Oracle Database upgrade and migration experts gives you all the details: what methods are available; how they work; and which is the best for your particular upgrade, migration, or consolidation scenario.

How an Oracle Database 12c Upgrade Works in a Multitenant Environment [CON7648]
Tuesday, Sep 30, 12:00 PM - 12:45 PM - Moscone South - 306

With the first patch set of Oracle Database 12c, you will be able to choose between various methods of upgrading a multitenant container database and its pluggable databases. In this session, you will hear from Oracle upgrade experts about all the details of how a database upgrade works in a multitenant environment. You will learn what your options are, how parallelism works for database upgrades, and what is new for database upgrades in the first patch set of Oracle Database 12c.

How and Why to Migrate from Schema Consolidation to Pluggable Databases [CON7649]
Wednesday, Oct 1, 11:30 AM - 12:15 PM - Moscone South - 306

One important use case for pluggable databases is to enable you to move from schema consolidation with multiple applications in the same database to a more secure environment with Oracle Multitenant and pluggable databases. In this technical session, you will hear from Oracle development experts about the methods available for migrating from schema consolidation to a multitenant database environment with Oracle Data Pump, transportable tablespaces, or new features in Oracle Multitenant.

Oracle Database 12c Upgrade: Tools and Best Practices from Oracle Support [CON8236]
This talk is not done by us but by our Global Tech Lead for Upgrades in Support, Agrim Pandit
Tuesday, Sep 30, 5:00 PM - 5:45 PM - Moscone South - 310

You’ve heard about Oracle Database 12c and its new capabilities. Now come hear from Oracle experts about all the great tools and resources Oracle offers to help you upgrade to Oracle Database 12c efficiently and effectively. This session’s presenters, from Oracle Support, bring years of database experience and recent lessons learned from Oracle Database 12c upgrades at companies of all sizes all around the world. You are sure to leave with valuable information that will help you plan and execute your upgrade. What's more, most, if not all, of the tools and resources they discuss are available to current customers at no additional cost through their standard product support coverage.

.

I will publish the schedules for the Hands-On-Lab (4x) and the location of the demo ground's booth as soon as I'll get it.

-Mike

Monday Jul 22, 2013

OTN Tour Latin America 2013

While Mike is in Shanghai for OOW, I'll be participating in the 2013 OTN Tour in Latin America. This week includes events in Panama, Costa Rica, and Mexico where I will have two sessions at each:

OTN Tour Header

Migrate and Consolidate your Databases using Data Pump

What ́s New in Database Upgrade

Both Mike and I will be participating in the August events in Uruguay, Argentina, and Brazil as well. But if you can't make it to these or other upcoming events, the slides are ready for download!

Thursday Jan 17, 2013

Potential check for corruptions

Having a corruption somewhere in the database is one of the worst case scenarios I could ever imagine - especially if it "sleeps" somewhere in the data dictionary. Recently I did talk to a customer who encountered a failing upgrade due to a data dictionary corruption gotten introduced in an earlier release.

What can you do to check your database(s) prior to an upgrade or generally from time to time? Actually I know now two powerful possibilities: 

  • hcheck.sql
    See MOS Note:136697.1
    This script will check for known problems in Oracle8i, Oracle9i, Oracle10g and Oracle 11g.
    You will need to create
    hOut Helper Package first - please see MOS Note:101468.1 to download the script hout.sql
  • RMAN validation:
    RMAN> backup check logical validate database;
    See MOS Note:836658.1 for further details - and you can run this with multiple parallel channels to speed up the run

Tuesday Jul 03, 2012

Data Pump: Consistent Export?

Ouch ... I have to admit as I did say in several workshops in the past weeks that a data pump export with expdp is per se consistent.

Well ... I thought it is ... but it's not. Thanks to a customer who is doing a large unicode migration at the moment. We were discussing parameters in the expdp's par file. And I did ask my colleagues after doing some research on MOS. And here are the results of my "research":

  • MOS Note 377218.1 has a nice example showing a data pump export of a partitioned table with DELETEs on that table as inconsistent
  • Background:
    Back in the old 9i days when Data Pump was designed flashback technology wasn't as popular and well known as today - and UNDO usage was the major concern as a consistent per default export would have heavily relied on UNDO. That's why - similar to good ol' exp - the export won't operate per default in consistency mode
  • To get a consistent data pump export with expdp you'll have to set:
    FLASHBACK_TIME=SYSTIMESTAMP
    in your parameter file. Then it will be consistent according to the timestamp when the process has been started. You could use FLASHBACK_SCN instead and determine the SCN beforehand if you'd like to be exact.

So sorry if I had proclaimed a feature which unfortunately is not there by default :-(

- Mike

Monday Dec 05, 2011

Exclude DBMS_SCHEDULER Jobs from expdp?

You have never thought about excluding DBMS_SCHEDULER jobs from a Data Pump export? Me neither but I've recently got a copy of an email for such a customer case from Roy who owns Data Pump as well. And this is the code example from Dean Gagne:

exclude.par:
exclude=procobj:"IN (SELECT NAME FROM sys.OBJ$ WHERE TYPE# IN (47,48,66,67,68,69,71,72,74))"

  • This will work only on export
  • It's an all or nothing approach

Quite interesting, isn't it? 

Tuesday Jul 19, 2011

How to get the Master Table from a Data Pump expdp?

Interesting question a customer had last week during the Upgrade Workshop in Munich. He's getting export dump files from several customers and often not much information describing the contents. So how can ge find out what's in there, which was the source characterset etc.

This seems to be a simple question but it did cost me a few searches and tests to come back with some (hopefully) useful information.Pump

First attempt: $strings expdp.dmp > outexpdp.txt

I bet there are better ways to do this but in my case this will give me:
"APP"."SYS_EXPORT_SCHEMA_01"
x86_64/Linux 2.4.xx
WE8ISO8859P15
LBB EMB GHC JWD SD EBE WMF DDG JG SJH SRH JGK CL EGM BJM RAP RLP RP KR PAR MS MRS JLS CET HLT
10.02.00.05.00

This does look interesting as it tells me the exporting user ('APP') , the source OS and - more important - the characterset of the source database (WE8ISO8859P15). 

But Data Pump has also a Master Table - and how do I read this table? We'll do a dummy import with impdp and keep the master table :-)

impdp system/oracle dumpfile=app.dmp SQLFILE=sql.txt nologfile=Y keep_master=y directory=DATA_PUMP_DIR

And voilà ... we have a sql file with all DMLs - and we have the master table:

Import: Release 11.2.0.2.0 - Production on Tue Jul 19 09:56:05 2011

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining
and Real Application Testing options
Master table "SYSTEM"."SYS_SQL_FILE_FULL_02" successfully loaded/unloaded
Starting "SYSTEM"."SYS_SQL_FILE_FULL_02":  system/******** dumpfile=app.dmp SQLFILE=sql.txt logfile=nologfile keep_master=y:q!
Processing object type SCHEMA_EXPORT/USER
Processing object type SCHEMA_EXPORT/SYSTEM_GRANT
Processing object type SCHEMA_EXPORT/ROLE_GRANT
Processing object type SCHEMA_EXPORT/DEFAULT_ROLE
Processing object type SCHEMA_EXPORT/PRE_SCHEMA/PROCACT_SCHEMA
Processing object type SCHEMA_EXPORT/TABLE/TABLE
Processing object type SCHEMA_EXPORT/POST_SCHEMA/PROCACT_SCHEMA
Job "SYSTEM"."SYS_SQL_FILE_FULL_02" successfully completed at 09:56:06

So the master table "SYSTEM"."SYS_SQL_FILE_FULL_02" is still kept and can be read to access information about the dump file.


16-AUG-2011:
Thanks to Marco Patzwahl from MuniQSoft for correcting my example to:

impdp system/oracle dumpfile=app.dmp SQLFILE=sql.txt nologfile=Y keep_master=y directory=DATA_PUMP_DIR
Using LOGFILE=NOLOGFILE will simply create a logfile called NOLOGFILE.log which was not my intention. And not specifying the directory will require that you start impdp from the actual Data Pump OS directory - by default $ORACLE_BASE/admin/<SID>/dpdump.
About

Mike Dietrich - Oracle Mike Dietrich
Master Product Manager - Database Upgrade & Migrations - Oracle Corp

Based near Munich/Germany and spending plenty of time in airplanes to run either upgrade workshops or work onsite or remotely with reference customers. Acting as interlink between customers/partners and the Upgrade Development.

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