How Can a Dedicated Audit Trail Table Improve Database Revision Tracking?

An Alternative Database Revision Tracking Strategy: The Audit Trail Table

Beyond the previously discussed design options, consider using a dedicated history table—an audit trail—to manage entity revisions. This centralized approach offers a comprehensive record of all database modifications.

Audit Trail Table Structure

The AuditTrail table includes these fields:

<code>[ID] [int] IDENTITY(1,1) NOT NULL
[UserID] [int] NULL
[EventDate] [datetime] NOT NULL
[TableName] [varchar](50) NOT NULL
[RecordID] [varchar](20) NOT NULL
[FieldName] [varchar](50) NULL
[OldValue] [varchar](5000) NULL
[NewValue] [varchar](5000) NULL</code>

Table Updates and Trigger Implementation

Triggers on each table capture changes. For every UPDATE or INSERT operation, the trigger:

1. Records the LastUpdateByUserID.
2. Logs the modified fields (including old and new values) into the AuditTrail table.

Advantages and Disadvantages

This method offers several benefits:

• Clear Revision History: Provides a detailed, chronological audit trail, perfect for reporting and compliance.
• Performance Optimization: Separating revision data from main entities can improve data access speed.
• Reduced Data Redundancy: Unlike previous designs, it avoids unnecessary field duplication.

However, consider these potential downsides:

• Increased Storage: The audit trail table's size can grow substantially with frequent database updates.
• Performance Overhead: The trigger mechanism and logging process may slightly impact write operation performance.

The above is the detailed content of How Can a Dedicated Audit Trail Table Improve Database Revision Tracking?. For more information, please follow other related articles on the PHP Chinese website!