Hi Team,
Recently we faced performance degradation situation which impacted overall operations of application.
From awr report, a proc is taking more than 3 or 4 seconds to complete. Lets call that proc 'A'.
In addmrpt, we are getting a statement similar to one given below:
Tune the entry point PL/SQL 'A' of type
"PROCEDURE". Refer to the PL/SQL documentation for
addition information.
Rationale
7821 seconds spent in executing PL/SQL "SYS.DBMS_SYSTEM.KSDWRT" of type
"PACKAGE".

We are focusing on proc 'A' because performance degradation happens when this proc is called on a regular basis (every one or two seconds).
But this proc is spending almost all of its time in executing SYS.DBMS_SYSTEM.KSDWRT. We have inferred this from awr and addm reports.

Since SYS.DBMS_SYSTEM.KSDWRT is undocumented, we are not getting any information on how this process is working internally.

My doubts are as follows:

1) How does SYS.DBMS_SYSTEM.KSDWRT manage to access the alert.log?
2) Is it using any oracle background process to access this log?
3) Can multipe sessions write to log concurrently or a wait occur there?
4) Does writing to log impact other DML operations?