For Exadata alerts accumulate pretty fast and it is not surprising to see 100-200 alerts in the history. Most of them are cleared but it is really a headache to clear those alerts. With this batch script you can save and drop the cleared alerts in an Exadata Db server. You can replace dbmcli with… Continue reading Save and Delete Cleared Alerts in Exadata
While upgrading oracle to 19C, you will see that WM_CONCAT is no longer available. Instaed of WM_CONCAT you can use these following options. Some has restrictions and I will point these restrictions. you can use listagg, but this has 4000 character limit after this limit it raises error.
ESS patch is applied on one of dataguard exadata box. After a successful ESS patch we started to see ping errors from our primary instance to dataguard nodes. We had such issue before and solved it using rp_filter parameter on linux. Solution is to briefly to relax the linux restriction for network configuration on the… Continue reading Exadata ping problems :rp_filter , martian source, ifcfg-bondeth0
DDL operations on your production may cripple your system. It is an all known fact. Especially when a Stored Procedure (SP), that has a dependency on that object, is heavily used. Most probably you can not compile it and you will have a lot of library cache pin, library cache lock … events. This post… Continue reading Stored Procedure Dependency May Crash Your Database
Last week I had to clone a database. I used backup based clone. The files were on the same exadata so I backuped up the files and cataloged them and then switch to the datafile copies with one simple rman command. I like simple and fast commands like this one My problem was the switch… Continue reading Recovery Area Wait Events
For read consistency oracle uses undo tablespace. In this post I will mention auto tuned undo management for a 11.2.0.4 database. We had space issues on our undo tablespaces. The extents remained unexpired and not recyled back to unexpired extends or free space. When we hit this space pressure point we had row cache waits.… Continue reading Undo Remains Unexpired
Lets talk about an interesting sql performance problem. Finding the cause of the problem was a challenge since it is not a daily sql tunning task. Actually the problem for the statement is not a general one. Sometimes you can run it in fractions of a second, sometimes (mostly the users) wait for the same… Continue reading Long Parse Time
We had 4 presentations on 2016 TROUG exadata event. This event is organized by TROUG. (Turkish Oracle User Group). I am glad that I had took part in this event. We had great time during the event. As TROUG, this year we had many other events and the biggest one was TROUG Days 2016 İstanbul.… Continue reading Exadata SIG 2016
During RMAN clone operation If your diskgroup do not have enough space for all the datafiles then you will get an error and the process will not finish. If you have enough free space over all the diskgroups then you can split the datafiles using those available diskgroups. For this purpose you can use the… Continue reading SET NEWNAME in action for RMAN clone
We had greate 3 days with the experts in their field. Pete Finnigan with great focus on Security. Database design according to the security principles. He also mentioned encryption, leakage of critical data, dangerous functions and use of incorrect privileges. Jonathan Lewis gave tons of examples from simple ones to complex ones and show how to… Continue reading Oracle University Istanbul Expert Summit 2014
Notes On Oracle 