ESRI recommends that ArcGIS be used to edit personal geodatabase data to ensure data integrity, specifically ArcCatalog or ArcMap applications. It is not recommended to edit personal geodatabase data with Microsoft Access.
Both regular Access database and personal geodatabase are represented as a single item in ArcCatalog and Windows.
The limitation of Microsoft Access as an application to edit personal geodatabase is that it does not understand the ESRI technology that is behind the personal geodatabase format. Even though the personal geodatabase format is based on the Microsoft Access data format, it is much more complex than the Access database format. For example:
· The Access database format does not support geographic features.
· Personal geodatabases contain hidden information that Access ignores.
· Personal geodatabases contain multiple underlying tables that provide information for a single feature class. When editing a feature class in ArcGIS, ArcGIS keeps track of changes in all the underlaying tables. Editing the geodatabase in Access may cause the underlaying tables to become out of sync and corrupt the geodatabase.
The Microsoft Access application has a lot of desirable functionalities, and there are many valid reasons to use an Access database. If use of an Access database is necessary, it is recommended that a regular Access database, separate from a personal geodatabase, be used to store the necessary information. To work with an Access database, it is possible to make an OLE DB connection to it in ArcCatalog. See the link in the Related Information section for more information on how to create an OLE DB connection.
There is no evidence to suggest that it is unsafe to open a personal geodatabase with Microsoft Access, but it is a risky process. It is safer to view and edit personal geodatabases with ArcGIS to avoid any accidental changes that can be made in Microsoft Access.