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Hi Martin, I'm not sure I would like to implement that kind of workaround. My recommendation for tha...
Franck, might it make sense to 1) create a startup-trigger to parse the statement with "most suita...
Martin Berger
I've used this method quite successfully in the past. In Oracle RAC, this will have to be done in ea...
Brian Peasland
Hi Franck, I don't know if the options will be addressed in the future. There are two note in M.O.S ...
I am aware of all these documents. Which leads to the following comment: - Customers are required to...
Pierre
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Franck's Oracle blog

Blog of Franck Pachot, Consultant at dbi services

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Franck Pachot

Franck Pachot

I'm a Senior Consultant, and Oracle Technology Leader at dbi services (Switzerland).
Certified DBA (OCM 11g, OCP 12c, Performance Tuning Expert, Exadata Implementation) I cover all database areas: architecture, data modeling, database design, tuning, operation, and training.
My preferred area is troubleshooting oracle and performance tuning, especially when I acheive to enable an efficient collaboration between the developers and the
operational team.


As an Oracle Ace, I participate in the Oracle Community in forums, blogs, articles and presentation. You can follow my activity on this blog: RSS and my twitter account: @FranckPachot


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If you want a statement to be hard parsed on its next execution, you can flush the shared pool, but you don't want all the cursors to be hard parsed. Here is how to flush only one statement, illustrated with the case where it can be useful.
During the performance training, here is how I introduce Adaptive Cursor Sharing, here is how I show the bind variable peeking problem that is well known by everyone that was DBA at the times of 9iR2 upgrades.

Tagged in: Oracle Performances
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This is a question that starts to be raised quite frequently. Oracle released the multitenant architecture 1.5 year ago. And now says that the previous architecture - known as non-CDB - is deprecated. What does it mean? Do we have to go to the CDB architecture even if we dont want to use/pay multi-tenant?

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This month we started to give our Oracle Tuning Workshop. And with a new workshop comes new questions. We advise to give to the optimizer the most accurate statsistics that we can have. That suggests that WORKLOAD statistics are better than NOWORKLOAD ones because they gather the average number of blocks read in multiblock read, rather than using default values. But then, the question is: which time period do you choose to gather workload statistics, and with which interval duration?

Tagged in: Oracle Performance
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In europe we have accents and non US7ASCII characters. We need special characterset. I'm not talking about Unicode here that solves all the problems. If you have a Java application, you have no problem: it's Unicode. You can store all characters in one multi-byte characterset. But for other applications, on Windows, you have 2 possible charactersets for Western Europe WE8MSWIN1252 and WE8PC850. WE8MSWIN1252 is the one that is set by default in the registry, but is it the right one?

Tagged in: NLS_LANG Oracle
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(english below)

Bonne nouvelle pour les francophones: le SOUG-R est de plus en plus actif.

Le 21 mai 2015 une journée performance est organisée sur Lausanne.

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in my previous post I've reproduced an issue where some bulk insert into a GTT was generating too much undo. But the real case I encountered was worse: the insert was reading lot of UNDO. And lot of this undo was read from disk.

Tagged in: flashback Oracle
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This post is about the case I had where a GTT was generating too much undo. The effects were amplified by the fact that the database was in flashback logging (see Jonathan Lewis answer in my question on OTN forum about that, but that's for the next post.

Tagged in: Oracle
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This is a second part of the previous post about metadata link. I've shown how a sharing=metadata function becomes a sharing=none function when it is changed in the pdb - i.e when not having the same DDL, not having a different signature.

Here is another experimentation doing the opposite: change the function in root and see what happens in the pdb. Again playing with internals in order to understand the 'upgrade by unplug-plug' feature available in 12c multi-tenant (and single-tenant).

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As in previous posts (1 and 2) I'm still playing with multitenant dictionary. You may wonder why I'm spending time to do unsupported things that we will never be able to use in real life.

Of course, playing with internals is fun ;)

But it's not only that. We will implement CDB databases (multi-tenant, and single-tenant as I think non-CDB will be deprecated in future versions). We will operate pluggable databases (clone, upgrade, downgrade,...), encounter issues, etc. Before doing that on critical environments, I need to be confident about the multitenant implementation. I'ts new, it's undocumented, and - at the first sight - it looks like a 'hack' in the way the dictionary is working for years.

Tagged in: internals Oracle 12c
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calendar          today  tomorrow  message
----------------- ------ --------- --------------
Arabic Hijrah     1436   1436
English Hijrah    1436   1436
Gregorian         2014   2015      Happy New Year
Japanese Imperial 0026   0027      Happy New Year
Persian           1393   1393
ROC Official      0103   0104      Happy New Year
Thai Buddha       2557   2558      Happy New Year

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