get your traces – yourself



I'd like to mention a small peace of software. It's called MrTrace and available in Version 2.0.0.43 right now. For me it's a tool to save time. So what is it doing at all?
MrTrace is a plugin for Oracles SQL Developer to access tracefiles via SQL Developer. It's previous version could only access the tracefile for the statement you just executed. But since version 2 you anyone with the right permissions access any tracefile in the trace directory.

For a DBA it does not sound spectacular to access tracefiles, but it can be quite annoying to get and (more...)

Setting Up Oracle Connection Manager (without SOURCE_ROUTE)


This post must be seen as a direct follow up to Arup Nandas Setting Up Oracle Connection Manager.
As there are many references to this post, please read it first. Problem and Solution are quite similar, only the architecture is a little bit different:

The Architecture

 The network diagram of the three machines is slightly different:


There is a new needed connection: from the instance on dbhost1 to the connection manager on cmhost1.

After changing the setup, you will need to rewrite the TNSNAMES.ORA in the following way:

TNS_CM = 
(DESCRIPTION =
(ADDRESS =
(PROTOCOL = TCP)(HOST = cmhost1)(PORT (more...)

Who created that process?

Figure 2-7
Connection to
a Dedicated
Server Process
For some reason I was really curios who created that process. It's not about a particular process in detail, mir a well known kind of processes. At least well known for DBAs.
Which process? 
It's one of these:

oracle   13096     1  0 20:05 ?        00:00:00 oracleTTT071 (LOCAL=NO)

Yes, it's a simple server process, nothing spectacular. Nevertheless, the Concepts guide is not very specific, who created that process. So I tried to find out in more detail.
On my linux sandbox the first column of ps -ef shows the UID, the second is the PID, the third (more...)

bzip2 twice?


To check the performance of RMAN backup I recently started to trace it a little bit. As most of the time was not spent in any reading from disk or writing to media manager library event, it was on CPU. It's good to know the CPUs are of any good, but as I still want to know what's going on I tried to dig any deeper. CPU cycles are not just a magic black box where we put in a problem and the answer comes out after some times. At an abstraction layer it's a chain of functions where one (more...)

non-Exadata HCC

Oracles Hybrid Columnar Compression was one of the big new features of Oracle 11.2. Unfortunately someone decided this feature should only be available in Exadata. Even Oracle tried to explain it with technical limitations, it was more or less obvious that's just wrong. There are some reasons for this:

  • The Database is doing the HCC compression all the time
  • The Database must be able doing the HCC decompression in case the storage cell can not or want not.
  • Beta-testers where very sure, HCC worked there without any special hardware.
  • Jonathan Lewis shows there are situations, where also an ordinary database (more...)