Pythian Group

Its all started from the question on communities.oracle.com
An “enhancement” in 11.2 prevents RMAN duplicating non self-contained subset of a database
where new feature of RMAN in 11.2 was shown which prevents duplication of sets of tablespaces if they are not self-contained.
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(story based on real events)
Where: Meeting room, Pythian office, Sydney, Australia.
When: Afternoon, after lunch time.
What: Discussion of planned maintenance for one of clients.
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If you support Oracle RDBMS 11.2.0.2 and want to zero downtime applying
patches to databases then it is time to have a look at new possibility
of Online Patching delivered with 11.2.0.2 version and described here
RDBMS Online Patching Aka Hot Patching [ID 761111.1]
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Every installation is unique. It can be the same software and hardware
but one installation will squease you like a lemon in jucier another one
will make you feel that you and only you is the boss here.

The way how it behaves depends not only on stars location and on
Saturn position in Zenith but also on how scripts finished, what SA did not
implement and change and how vigorously developers spent a day.

In any case you should put all your heart to the process either it is GUI
or silent installation, feel the breath of installer and give heed to every
entry appeared in the output log.
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During database maintenance one of the main questions is when long running processes
like export, import, backup, recovery, flashback, etc. are finished.

I usually use v$session_longops which allows to get some estimation of when process finished:

select message, time_remaining/3600 hrs from v$session_longops where sofar <> totalwork

After one of the recent Data Pump executions I tested import and export on Oracle 11.1.0.7 Linux 64-bit
and found that for both export and import master processes value of message column in v$session_longops
stays something like “0 out of … MB done” during the whole process even it is far away from the beginning.
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The new functionality to download latest patches or either apply saved ones
came with installer of Oracle 11.2.0.2 (Software Updates Option)

It can be used not only through OUI but with silent installation too.
There are several options and variables available to get patches from MOS:
oracle.installer.autoupdates…
MYORACLESUPPORT_…
AUTOUPDATES_MYORACLESUPPORT_…

Putting it all together I got the following selection of options and parameters that was started and
successfully completed (operations and their status were logged to logs under oracle inventory):

./runInstaller -silent -responseFile /home/oracle/install/patchset1/database/response/db_install.rsp \
-downloadUpdates \
AUTOUPDATES_MYORACLESUPPORT_USERNAME=... \
AUTOUPDATES_MYORACLESUPPORT_PASSWORD=... \
oracle.installer.autoupdates.option=MYORACLESUPPORT_DOWNLOAD \
oracle.installer.autoupdates.downloadUpdatesLoc=/tmp/updates

There was nothing displayed for that execution but in log file there were following entries:

INFO: Retrieving list of updates
INFO: UpdateManager: retrieving value for key: UPDATE_VERSION
INFO: UpdateManager: retrieving value for key: UPDATE_VERSION value: 11.2.0.2.0
INFO: UpdateManager: retrieving value for key: UPDATE_BUGID
INFO: UpdateManager: retrieving value for key: UPDATE_BUGID value: 9794229
INFO: Connection to metalink was successful
INFO: No of components in db install : 136

Search on MOS found patch 9794229 called “PLACEHOLDER BUG FOR METADATA XML IN 11202″
which is just a container for possible critical and security patches in the future.
(Worth to note that after recent upgrade MOS exposed very helpful feature to get wget
script to download patches. You will see it in download box when you click on download button)

There is also option of installer to apply already downloaded and saved patches:

oracle.installer.autoupdates.option=OFFLINE_UPDATES
oracle.installer.autoupdates.downloadUpdatesLoc=/tmp/updates

To try the option I downloaded one of the patches for 11.2.0.2 (there are several dozens of them already),
put it under /home/oracle/install/patches, unpacked it there and executed silent installation
without previously used AUTOUPDATES_MYORACLESUPPORT_…:

./runInstaller -silent -responseFile /home/oracle/install/patchset1/database/response/db_install.rsp \
AUTOUPDATES_MYORACLESUPPORT_USERNAME=... \
AUTOUPDATES_MYORACLESUPPORT_PASSWORD=... \
oracle.installer.autoupdates.option=OFFLINE_UPDATES \
oracle.installer.autoupdates.downloadUpdatesLoc=/home/oracle/install/patches

but it failed with error:”[SEVERE] – My Oracle Support Username/Email Address Not Specified”

I replaced AUTOUPDATES_MYORACLESUPPORT_… with MYORACLESUPPORT_… parameters
and executed it once more:

./runInstaller -silent -responseFile /home/oracle/install/patchset1/database/response/db_install.rsp \
MYORACLESUPPORT_USERNAME=... \
MYORACLESUPPORT_PASSWORD=... \
oracle.installer.autoupdates.option=OFFLINE_UPDATES \
oracle.installer.autoupdates.downloadUpdatesLoc=/home/oracle/install/patches

and another error appeared:
CAUSE: The location provided is not in the expected directory structure.
ACTION: For auto-updates to work in offline mode,
the location of the downloaded updates should be in a particular format.
Please refer to the doc for details.
The same happened when I executed OUI and chose the same option there.

Unfortunately, search in Oracle documentation had not returned anything but MOS
returned one document related to auto updates in Grid Control (ID 1099123.1) where similar
auto updates feature is used for Grid Control and there is patches.xml file that has all information about
patches and to what product they should be applied.

I copied patch 9794229 “PLACEHOLDER BUG FOR METADATA XML IN 11202″ downloaded before and
to /home/oracle/install/patches and unzipped there but installer failed again even I got patches.xml file under the location.

Even there was no success for now to apply already downloaded patches I believe it will be revealed soon
since Auto Update feature can be useful especially when there is no any CPU yet
and installer can execute patches that you decided are applicable for your database environment.

Have a good day!

There is a new tool came with Oracle 11g Rel.2 that helps to modify options in
installed oracle home (Enabling and Disabling Database Options)
It is very simple and straightforward utility that recompiles database kernel
with different flags.

[oracle@r1 bin]$ chopt
usage:
chopt  <enable|disable> <option>
options:
                  dm = Oracle Data Mining RDBMS Files
                  dv = Oracle Database Vault option
                lbac = Oracle Label Security
                olap = Oracle OLAP
        partitioning = Oracle Partitioning
                 rat = Oracle Real Application Testing
e.g. chopt enable rat

There is no “list” command that can show installed options for the selected home
although it can be helpful and useful to have such option.

Initially enabled options can possibly be seen in $ORACLE_HOME/install/make.log file
(flags were set as compilation options for ins_rdbms.mk) but it can be changed over time
and not always relfect the current configuration.

Knowing that there is XML file for properties of oracle home wouldn’t be
$ORACLE_HOME/inventory/ContentsXML/oraclehomeproperties.xml
a good place to track list of oracle home configured options?

And finally the tool does not take into account several options at once, it simply ignores
all parameter after the second one:

[oracle@r1 bin]$ chopt enable dm dv

Writing to /u01/app/oracle/product/11.2.0/dbhome_1/install/enable_dm.log...
/usr/bin/make -f /u01/app/oracle/product/11.2.0/dbhome_1/rdbms/lib/ins_rdbms.mk dm_on ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1
/usr/bin/make -f /u01/app/oracle/product/11.2.0/dbhome_1/rdbms/lib/ins_rdbms.mk ioracle ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1/
[oracle@r1 bin]$

Have a good day!

oraenv is great utility that helps to control environment
and to avoid exact use of ORACLE_… variables in scripts.
With invention of ORACLE_BASE it was enhanced to change the variable
and to print the value in the output.

But with more than one oracle homes installed that use not the same oracle base
path it does not switch oracle bases and leaves it to be the same as it is selected
during the first execution of oraenv(switching $ORACLE_BASE using oraenv in 11g)

More interesting that behaviour of oraenv in 11.2.0.2 has been changed
and now it is able to switch oracle base variables but it does not
show oracle home path in the output, only oracle base:

[oracle@r1 trace]$ . oraenv
ORACLE_SID = [r1] ? t1
The Oracle base has been changed from /u01/app/oracle to /u04/app/oracle
[oracle@r1 trace]$ . oraenv
ORACLE_SID = [t1] ? r1
The Oracle base has been changed from /u04/app/oracle to /u01/app/oracle

Is that a new feature or just a bug that does not show oracle home path
in oraenv output…

Have a good day!

I was co-presenting recently at Sydney Oracle Meetup
about Data Guard Compression and in preparation I did
some tests to see how it works for 11.2.0.1 (Linux x86-64)

…and I am still not able to see it working.

There is a note “Redo Transport Compression in a Data Guard Environment [ID 729551.1]“
on MOS how to set compression for redo transport destination
and for log archive gaps but none of those settings helped to see compression
reported neither in trace files nor in v$archived_log view (compressed column).

Possibly at first compression for archive logs was mentioned in the
“Archivelog compression?” post but even “alter database archivelog compress enable”
works in 11.2.0.1 (still not documented)
it does not affect compression of archive logs although archivelog_compression in
v$database changed to ENABLED.

Later on I checked ability of alter database… to influence compression of archive logs
in 11.1.0.6 and 11.1.0.7 (Linux x86-64) and got positive results:

in both versions archive logs of 50M were decreased in size to ~10M
and trace file for ARCH process was updated with information about ratio
of compression:

Archivelog compression complete.
  Input: 50969088 bytes Output: 10307875 bytes
  Compression Performance: 79.78 percent or 1.62 bits per byte

But for 11g Rel.2 database created from predefined templates compression did not work.
Does it require some special additional options or specific hidden parameters configuration
in addition to mentioned in the note COMPRESSION=ENABLE and “_redo_transport_compress_all”
(which by default set to TRUE)?

Definitely truth is out there…

Have a good day!

One of the first questions that I asked myself when EM GC 11g came out is how would a silent
installation go especially taking into account the use of WebLogic server as the http server.

But before any attempt of silent installation I started the GC 11g GUI installation to local VM machine
(Oracle Enterprise Linux 5.4 64-bit) with an allocated 2Gb of memory and got errors since
WebLogic server was not installed there.
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