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,…
Troubleshooting Oracle session disconnection slowness
I have been recently asked to investigate very interesting issue. In short: AIX 7.1 with Oracle 12.1.0.2. Connect with SQL*Plus from hostX to databaseA running on hostZ, then disconnect – was hanging for around 75 seconds. Connect with SQL*Plus from hostY to databaseA running on…
Fast Recovery Area space usage threshold
Using Fast Recovery Area to let Oracle automatically manage the backup/flashback/recovery related files is very useful, but avoiding problems related with FRA free space shortage requires careful planning. There are several factors that have to be taken into account, apart from the most obvious like…
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,…
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…
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…
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. Recently I had such a problem and…
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