Recompilation

Database Migration from non-CDB to PDB – Plug in, upgrade, convert

This is my next blog post about Database Migration from non-CDB to PDB – Plug in, upgrade, convert. But what is different from the previous one? And why is it necessary? Since Oracle Database 12.2.0.1 you can plugin a non-CDB at first, the upgrade and convert it. And I’ll show you this technique here.

Database Migration from non-CDB to PDB – Plug in, upgrade, convert

Photo by Dan Freeman on Unsplash

High Level Overview

Endianness change possible: No
Source database versions: Oracle 12.2.0.1 or newer (or 12.1.0.2 when CDB has shared UNDO)
Characteristic: Plugin into CDB first
Upgrade necessary: Yes, after plugin
Downtime: Plugin, copy (optional), upgrade and noncdb_to_pdb.sql
Minimal
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utlrp.sql – How to decrease resource consumption with utlprp.sql

 utlrp.sql - How to decrease resource consumption with utlprp.sqlJust being back from Oracle Open World 2017 I’m working on the open topics, the homework, the follow-up activities. And I took several notes during OOW when customers asked me about things I’ve seen before.

One topic I wanted to write about a long time ago already: utlrp.sql – How to decrease resource consumption with utlprp.sql.

Where it started

Actually it’s all Uwe’s fault (Uwe Kirchhoff is one of my best and oldest friends at Oracle and one of the best ACS guys I can think of). Uwe told me this story about a customer case he …

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Will gathering fixed object stats reduce recompilation time post upgrade?

Interesting question, isn’t it?
Will the time to recompile invalid objects post upgrade decreased once fixed object stats have been gathered?

First of all fixed object stats on X$-tables won’t be gathered by default [This will change with Oracle 12c where it is part of the Auto Stats Gathering job].
X$ structures are undocumented. V$ views are build on top of them and
should only be used even though it might be sometimes useful to access
X$ tables such as X$BH (buffer headers – contains information describing the current contents of a piece of the buffer cache

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