No data with DB Analysis?
I am trying to use one of the DB tools that come with SAP. So, I do the following:
1. Txn db02old
2. Menu : DB Analysis -> Other DB Analysis
Firstly, I saw that buffer busy waits was > 0. Since the system uses Locally Managed Tablespaces, should this not be 0???
I then went to:
--> Wait Event Analysis
-----> Buffer Busy Waits
Double-clicking on this does not work. It produces nothing. What is one supposed to do?
Stefan Koehler replied
But with ASSM,
>-> There is no need to read the header of a segment
>-> There is no need to traverse any kind of list looking for free blocks (i.e. there are no blocks to read)
You also need to read the segment header, if you are using ASSM. The difference between manual and automatic segment space handling is the type of finding free blocks. The ASSM is using something like an index structure.
There is no linked list between the block headers.. but the segment header and some other blocks (level X BMBs) also need to be read.
If you really want to know this in detail.. please check this really great presentation from Tanel Põder: