Most web apps I've worked on have had queues in the database. The operational simplicity of only having a database has far outweighed the code complexity of usi

Most web apps I've worked on have had queues in the database. The operational simplicity of only having a database has far outweighed the code complexity of using the relational database as a queue. However the performance would not have scaled. Luckily the performance was well above peak load of the actual systems.