oratop Command in Oracle
- Alireza Kamrani
Overview
The oratop command is a real-time Oracle database performance monitoring tool — similar to the Linux top command, but designed specifically for Oracle Database environments. It provides a dynamic, continuously refreshing view of key performance metrics at the instance, session, and SQL levels, making it an essential utility for DBAs who need quick situational awareness without the overhead of complex diagnostics tools like Enterprise Manager.
Details:
Tool name: oratop
Purpose: Real-time performance monitoring for Oracle Database
Source: Developed by Oracle Support (MOS script)
Availability: Downloadable from My Oracle Support (MOS Note 1500864.1)
Supported Versions: Oracle Database 11g and higher (including 19c and 23ai)
Installation & Setup:
oratop is a Perl-based script that connects to the database through SQL*Plus.
You can download it from My Oracle Support (MOS Note 1500864.1).
Steps:
1. Download the latest version (oratop_latest.zip) from MOS.
2. Unzip the file:
unzip oratop_latest.zip
3. Make it executable:
chmod +x oratop
4. Ensure sqlplus is in your PATH and environment variables (ORACLE_HOME, ORACLE_SID) are set.
Usage Examples
Local connection:
oratop / as sysdba
Remote connection:
oratop user/password@tns_alias
For RAC:
oratop /@service_name inst#
Example: oratop /@orcl1 2
Interface Overview
Once launched, oratop displays a refreshing console interface divided into several sections:
1. Header Section — Instance summary (database name, version, uptime, load, sessions, wait classes)
2. Activity Section — Real-time CPU, session count, I/O, TPS
3. Top Sessions / SQL Section — SID, username, SQL ID, event, CPU, I/O usage
Interactive commands:
s – Session view
i – Instance summary
q – Quit
Common Options
oratop / as sysdba 5 10 → Refresh every 5 seconds, 10 iterations
-f → Flat file mode (output to text)
-n → Non-interactive batch mode
-i → Instance number for RAC
-a → Display all RAC instances
-h → Help and usage options
Example Output:
oratop: Release 15.0 Oracle 19.18.0.0.0
DBNAME INST_ID HOST UP: 3 days Load: 2.3
CPU: 85% Busy IO: 15% Wait Sess: 120 Active: 12
Event: "log file sync" Waits: 123/s
Event: "db file sequential read" Waits: 98/s
Top Active Sessions:
SID USERNAME SQL_ID EVENT CPU% WAIT%
123 APPUSER 2gq1b78xj.. db file sequential read 30 20
345 SYS 5j3fkw2h9.. log file sync 25 15
Licensing and Benefits
oratop does not require the Oracle Diagnostic Pack license since it uses only standard dynamic performance views (v$, gv$). It is safe for production environments.
Benefits:
• Lightweight and agentless
• Real-time performance visibility
• RAC-aware monitoring
• Ideal for quick triage
• Customizable refresh and filters
Summary Table
Feature | Description |
Type | Command-line real-time monitor |
Language | Perl |
Connection | SQL*Plus |
Supports RAC | Yes |
License | Free (no Diagnostic Pack needed) |
Best for | Quick real-time instance and session performance analysis |
Conclusion
oratop is an essential command-line tool for Oracle DBAs who need immediate insights into system performance without heavy GUI overhead. It bridges the gap between command-line simplicity and Enterprise Manager’s diagnostic depth — empowering database administrators to act fast, diagnose bottlenecks, and maintain high system performance.
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