Waitfailed

Waitfailed is a term used in Oracle databases to describe a specific error condition that occurs when a database operation, typically a queue or a database transaction, cannot complete. The term is derived from the Oracle database error message "WAITED failed" which indicates that a thread or process has timed out while waiting for a resource or event.

This error is often seen in multi-user systems where concurrent access to the database is taking place. The cause of the waitfailed error is typically related to:

1) Contention for database resources such as locks, latches, or other shared resources.

2) Insufficient buffer space or capacity in memory to process tasks.

3) Deadlocks where two or more threads are holding locks on database records in such a way that the threads cannot proceed without releasing the locks held by the other, in effect causing them to lock indefinitely.

To resolve the waitfailed condition, database administrators can employ various techniques such as:

1) Allocating additional buffer space or resources in memory.

2) Improving the database configuration to address resource contention.

3) Analyzing and tuning query performance for the involved transactions.

Monitoring the database and assessing the performance metrics can provide insight into the underlying cause of the waitfailed error. This information can then be used to adjust the database configuration, perform necessary maintenance, or implement changes to software or queries involved. By identifying and addressing the root cause of the waitfailed error condition, database availability and overall performance can be improved.