Snapshot Too Old

Undo space cannot save historical data if the execution time of the query SQL statement is too long or other reasons. Therefore, an error may be reported if the historical data is forcibly recycled. Generally, the rollback segment space needs to be expanded. However, the specific problem needs to be analyzed.

• Undo Space Recycling Blocked by Long Transactions
  
• Slow Undo Space Recycling Caused by Many Rollback Transactions