Set - 8

Question 51 :

Where can one get more information about TCL? (for DBA)

Answer :

One can write custom event checking routines for OEM using the TCL (Tool Command Language) language. Check the following sites for more information about TCL:
. The Tcl Developer Xchange - download and learn about TCL
. OraTCL at Sourceforge - Download the OraTCL package
. Tom Poindexter's Tcl Page - Oratcl was originally written by Tom Poindexter


Question 52 :

Are there any troubleshooting tips for OEM? (for DBA)

Answer :

. Create the OEM repository with a user (which will manage the OEM) and store it in a tablespace that does not share any data with other database users. It is a bad practice to create the repository with SYS and System.
. If you are unable to launch the console or there is a communication problem with the intelligent agent (daemon). Ensure OCX files are registered. Type the following in the DOS prompt (the current directory should be $ORACLE_HOME\BIN:
C:\Orawin95\Bin> RegSvr32 mmdx32.OCX
C:\Orawin95\Bin> RegSvr32 vojt.OCX
. If you have a problem starting the Oracle Agent
Solution A: Backup the *.Q files and Delete all the *.Q Files ($Oracle_home/network/agent folder)
Backup and delete SNMP_RO.ora, SNMP_RW.ora, dbsnmp.ver and services.ora files ($Oracle_Home/network/admin folder) Start the Oracle Agent service.
Solution B: Your version of Intelligent Agent could be buggy. Check with Oracle for any available patches. For example, the Intelligent Agent that comes with Oracle 8.0.4 is buggy.
Sometimes you get a Failed status for the job that was executed successfully.
Check the log to see the results of the execution rather than relying on this status.


Question 53 :

What is import/export and why does one need it? (for DBA)

Answer :

The Oracle export (EXP) and import (IMP) utilities are used to perform logical database backup and recovery. They are also used to move Oracle data from one machine, database or schema to another.
The imp/exp utilities use an Oracle proprietary binary file format and can thus only be used between Oracle databases. One cannot export data and expect to import it into a non-Oracle database. For more information on how to load and unload data from files, read the SQL*Loader FAQ.
The export/import utilities are also commonly used to perform the following tasks:
. Backup and recovery (small databases only)
. Reorganization of data/ Eliminate database fragmentation
. Detect database corruption. Ensure that all the data can be read.
. Transporting tablespaces between databases
. Etc.


Question 54 :

What is a display item?

Answer :

Display items are similar to text items but store only fetched or assigned values. Operators cannot navigate to a display item or edit the value it contains.


Question 55 :

How does one use the import/export utilities? (for DBA)

Answer :

Look for the "imp" and "exp" executables in your $ORACLE_HOME/bin directory. One can run them interactively, using command line parameters, or using parameter files. Look at the imp/exp parameters before starting. These parameters can be listed by executing the following commands: "exp help=yes" or "imp help=yes".
The following examples demonstrate how the imp/exp utilities can be used:
exp scott/tiger file=emp.dmp log=emp.log tables=emp rows=yes indexes=no
exp scott/tiger file=emp.dmp tables=(emp,dept)
imp scott/tiger file=emp.dmp full=yes
imp scott/tiger file=emp.dmp fromuser=scott touser=scott tables=dept
exp userid=scott/tiger@orcl parfile=export.txt
... where export.txt contains:
BUFFER=100000
FILE=account.dmp
FULL=n
OWNER=scott
GRANTS=y
COMPRESS=y
NOTE: If you do not like command line utilities, you can import and export data with the "Schema Manager" GUI that ships with Oracle Enterprise Manager (OEM).