This question frequently asked “Is APO ABAP different from normal ABAP” ?
Answer is “NO”
APO ABAP is same as normal ABAP, we can use all command, all syntax of normal ABAP, only difference is in architecture of APO, transactional data in APO is saved in LiveCache (a memory database) not in tables like R/3 hence we cannot extract transactional data in APO using “SELECT” statements nor we can use other database commands instead of it we have to use standard BAPIs/FMs to handle data in LiveCache.
Also data stored in LiveCache as Time Series / Order Series
For more details you can refer my book 🙂