Data Queues在程式間採用非同步(asynchronous)通訊方式, Socket則是則是採同步通訊的方式作業.
Data Queues的好處有
- performance can be dramatically improved over individual submits if the job is complex
- record locking conflicts are eliminated if only one job is updating.
- they can facilitate clean modular design
Data Queues的壞處為
- they are hard to document well - the next programmer will have to think to figure them out
- they can't really be audited, backed up, or for that matter conveniently examined.
- the contents are almost invisible, although smart programmers have written program to read the queue, print the entry, and re-write it.
- Once the entry is read it is gone; if the program halts the entry is lost. This can be gotten around with an audit file; write a record when the entry is written, nad have the receiver program update a status field when done.
詳細參考以下這篇文章
http://www.news400.com/resources/clubtech/tnt400/bo400ng/as400dataqs.htm