Optimize Oracle SQL with SQL Health Check (SQLHC)
Introduction
SQL Health Check (SQLHC) is a powerful tool provided by Oracle for diagnosing and tuning SQL statements. It helps database administrators (DBAs) identify potential performance
issues and provides detailed recommendations for optimization. This blog will guide you through the process of using SQLHC, from downloading it to generating comprehensive
health check reports.
Steps to Use SQLHC
1. Download SQLHC
The SQLHC tool is available for download from Oracle Support. Follow these steps:
- Log in to Oracle Support with your credentials.
- Locate the document with ID 1366133.1.
- Download the SQLHC tool from the provided link.
2. Log in to Oracle
Log in to your Oracle database using the following command. Ensure you have the necessary privileges (e.g., SYS or DBA role).
sqlplus sys/password@your_database as sysdba
3. Identify the SQL_ID
Find the SQL_ID of the statement you want to tune. Use the following query to locate it:
SELECT sql_id, sql_text
FROM v$sql
WHERE sql_text LIKE '%your_query%';
4. Determine Your Oracle Pack License
Check which Oracle Pack license your organization uses. This affects the features available in SQLHC:
- Tuning Pack (T): Offers advanced tuning options.
- Diagnostics Pack (D): Provides diagnostic tools but limited tuning features.
- None (N): Use this if neither pack is available.
5. Execute the SQLHC Script
Run the sqlhc.sql script with the appropriate Oracle Pack license and SQL_ID. This generates HTML reports with performance insights.
SQL> @sqlhc.sql T g4pkmrqrqxg3b
Analyzing the SQLHC Report
The SQLHC script produces HTML reports with valuable information, including:
- SQL Text: Displays the complete SQL statement.
- Execution Plan: Shows how Oracle executes the SQL statement.
- Statistics: Details on the objects and statistics involved in execution.
- Recommendations: Suggestions for improving SQL performance, such as indexing, query rewriting, or statistics gathering.
Conclusion
Utilizing SQLHC can significantly improve SQL performance in Oracle databases. By following the outlined steps, you can effectively use SQLHC to generate detailed health check reports, which offer actionable recommendations for SQL optimization.
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