8
Monitoring a Database

This chapter describes how to monitor Oracle8i Personal Edition for Windows 98.

Specific topics discussed are:

• Database Monitoring Overview

• Using Trace and Alert Files

Database Monitoring Overview

The following tools enable you to monitor your Oracle8i database:

This Tool	Enables You To...
Trace Files	Record occurrences and exceptions of database operations.
Alert Files	Record important information about error messages and exceptions during database operations.

Each tool is described in the following sections.

Additional Information: See Oracle8i Tuning and Performance for general tuning information.

Using Trace and Alert Files

Oracle8i Personal Edition for Windows 98 background threads use trace files to record occurrences and exceptions of database operations, as well as errors. Background thread trace files are created regardless of whether the BACKGROUND_DUMP_DEST parameter is set in the INIT.ORA initialization parameter file. If BACKGROUND_DUMP_DEST is set, the trace files are stored in the directory specified. If the parameter is not set, the trace files are stored in the ORACLE_BASE\ADMIN\DB_NAME\BDUMP directory.

Oracle8i database creates a different trace file for each background thread. The name of the trace file contains the name of the background thread, followed by the extension.TRC. Sample trace file syntax includes:

• SIDDBWR.TRC

• SIDSMON.TRC

where SID represents the name of the instance.

Trace files are also created for user threads if the USER_DUMP_DEST parameter is set in the initialization parameter file. The trace files for the user threads have the form ORAxxxxx.TRC, where xxxxx is a 5-digit number indicating the Windows 98 thread ID.

The alert file contains important information about error messages and exceptions that occur during database operations. Each Oracle8i Personal Edition for Windows 98 instance has one alert file; information is appended to the file each time you start the instance. All threads can write to the alert file.

For example, when automatic archiving of redo logs is halted because no disk space is available, a message is placed in the alert file. The alert file is the first place to check if something goes wrong with the database and the cause is not immediately obvious.

The alert file is named SIDALRT.LOG and is found in the directory specified by the BACKGROUND_DUMP_DEST parameter in the INIT.ORA initialization parameter file. If the BACKGROUND_DUMP_DEST parameter is not set, the SIDALRT.LOG file is generated in ORACLE_BASE\ADMIN\DB_NAME\BDUMP. Alert files should be deleted or archived periodically.