Each of the layers is stored in physical file with the naming AX<layer>.AOD. Each layer has two file, one is layer file and another is Services Packs file.The filename for the sys layer is AXSYS.AOD(AXSYP.AOD). The layers are indexed in the file AXAPD.AOI. If deleted, the index file is built automatically at startup. If a layer file is deleted or added, the index file will also be rebuilt. You might end up in a situation where you cannot locate an object in the AOT, or other strange system behavior such as the AOT crashing when a certain object is accessed. Then it might help to delete the index file and have it rebuild at startup. To rebuild the index file all users must be logged out, shut down the Application Object Server (AOS). Start a single two-tier client to rebuild the index (MorphX Book)
If an object was deleted in AOT, but this user's session was not break, we can restore it in AOT Recycle Bin. If user log off system, all can't be restore. If it is a table, all data can't be restored. But table structure can be restored.
通常，我们在table上增加一个字段后，对应的form,report的数据源不会马上更新，这个时候对着这个form或者report右键，restore一下，马上就同步了
