Files - Expert Oracle Database Architecture - page 92

Prior to Oracle 11 g and the addition of the Default Trace File information, you had to locate your trace file
manually. If you use a shared server connection to Oracle, you are using a background process so the location of your
trace files is defined by background_dump_dest . If you use a dedicated server connection, you are using a user or
foreground process to interact with Oracle so your trace files will go in the directory specified by the user_dump_dest
parameter. The core_dump_dest parameter defines where a “core” file would be generated in the event of a serious
Oracle internal error (such as a segmentation fault on UNIX/Linux), or if Oracle Support had you generate one
for additional debug information. In general, the two destinations of interest are the background and user dump
destinations. Unless otherwise stated, we will be using dedicated server connections in the course of this topic, so all
of our trace files will be generated in the user_dump_dest location.

Naming Convention
The trace file naming convention changes from time to time in Oracle, but if you have an example trace file name from
your system, it is easy to see the template in use. For example, on my various UNIX/Linux servers, a trace file name
looks like those in Table 3-1 .

Table 3-1. Sample Trace File Names

Trace File Name Database Version

ora_10583.trc 9 i Release 1

ora9ir2_ora_1905.trc 9 i Release 2

ora10gr2_ora_6793.trc 10 g Release 2

ora11gr2_ora_1990.trc

11 g Release 2

ora12cr1_ora_2344.trc 12 c Release 1

On my servers, the trace file name can be broken down as follows:

ORACLE_SID (with the exception of Oracle9 i Release 1,
where Oracle decided to leave that off ).

• The first part of the file name is the

ora . • The next bit of the file name is just

• The number in the trace file name is the process ID of your dedicated server, available to you

from the V$PROCESS view.
Therefore, prior to Oracle 11 g , which has the easy to use V$DIAG_INFO view, in practice (assuming dedicated
server mode) you need access to four views to determine your trace file name:

V$PARAMETER , which is used to locate the trace file for user_dump_dest and to find the optional
tracefile_identifier that might be used in your trace file name.

•

V$PROCESS , which is used to find the process ID. •

V$SESSION , which is used to correctly identify your session's information in the other views. •

V$INSTANCE , which is used to get the ORACLE_SID .
As noted earlier, you can use the DBMS_UTILITY to find the location, and often you simply “know” the ORACLE_SID ,
so technically you might only need access to V$SESSION and V$PROCESS , but for ease of use you'd want access to all four.

•