Cross-endian Oracle migration – moving user data – part II

In my previous post I shared some findings on migrating user and application data between platforms with different endianness, focusing on problems with reducing downtime.

Today I’ll talk more about the complexity of chosen method. It’s not only about complexity per se, it’s rather about the possibility to automate as much as possible in order to allow efficient migration of a big number of databases.

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Cross-endian Oracle migration – moving user data – part I

One can find a lot of sources and materials regarding migrating Oracle databases between platforms having different endianness, even though the choice of possible methods is limited in this case. On paper (slides?) everything looks fine, but then you hit bugs or environment-specific problems. Moreover, in real life the situation is always more complex than moving just one tablespace with just one datafile as shown in many places as an example. Today I would like to add my 2 cents into this topic, focusing on moving user and application data.

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Redo Transport from Oracle 11.2 to 12.2 and SYS password case-sensitivity problems

Case-sensitive passwords were introduced in Oracle Database 11g, causing some misunderstanding and introducing quite a lot of annoying problems for DBAs, even though it was really required to bring level of Oracle’s security to 21st century standards ;). Since then, even more changes were introduced, including for example deprecation of SEC_CASE_SENSITIVE_LOGON database parameter, IGNORECASE argument of ORAPWD tool or password file format change in 12c.

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Migrating from Windows to Linux with Active Duplicate for standby – problem with 11.2.0.4

Recently I was working on migrating Oracle 11.2.0.4 database running on Windows, to new hardware infrastructure on Linux. This Oracle version is with us for quite a long time, plus migration from Windows to Linux is quite common (fortunately in that direction…;)), so when I got an error while trying to use Active Duplicate feature to create a standby database, I was quite sure I’ll be able to quickly find the solution either in MOS or elsewhere. Indeed, I found several blog posts with exactly the same error, but solution mentioned there was not working for me.

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Bloom filters and parallel execution

Today I want to share with you another interesting example of solving performance problem which happened in the database used for Business Intelligence purposes. Users were complaining that the performance in kind of staging database (STGDB) was much better than the production one (PRDDB), even though the dataset was exactly the same.

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Playing with statistics modification hints

How often did you have the situation when performance problem disappeared just after refreshing object statistics? Of course it is nice to solve the problem quickly and simply, but is always better to understand what has exactly happened.

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