ESRI New file geodatabase format

New Geodatabase format
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Until now, single-user geodatabases in ArcGIS have been personal geodatabases stored in Microsoft Access.Personal geodatabases satisfy basic requirements. However their performance slows markedly as the size of datasets stored in them increases, and they have a 2 GB overall database size limit. Accessing a personal geodatabase over a network concurrently with other users can present additional problems; performance slows further and data locks can stay around longer than you’d expect, blocking other users from accessing the data.
ArcGIS 9.2 introduces an alternative, a new type of single-user geodatabase referred to as the file geodatabase. A file geodatabase stores datasets as a folder of files on your file system, much like you’d store a folder of shapefiles. Individual datasets can be as large as 1 terabyte and there is no overall database size limit. Compared to personal geodatabases, file geodatabases improve performance, store vector data more efficiently, and improve concurrency and multi-user access over a network. You can also optionally store vector feature classes and tables in a compressed, read-only format to reduce storage requirements further. File geodatabases are also fully supported across platforms. One of the driving forces behind introducing this format was to provide support on both Windows and UNIX. For example, you can use Java to create and access file geodatabases on UNIX.
To create a file geodatabase, right-click a folder in the ArcCatalog tree view and click New, then click File geodatabase.
Personal geodatabases continue to be fully supported at 9.2. You can continue to create and work with personalgeodatabases just as you always have. Personal geodatabases can be upgraded to 9.2 in the usual way so that you can use them with all the new functionality introduced at 9.2.
Personal geodatabases and file geodatabases look the same in ArcCatalog, and the structure of the data within them is the same. You can easily move data from one to another with the Copy and Paste commands. You also work with them the same way, whether accessing data through ArcCatalog or ArcMap, or through ArcObjects as you’re developing a custom application. The only exception to this is the syntax you use to perform a SQL query in ArcMap: there are some slight differences.
In the Desktop Help, see these topics:
Mapping and visualization > Navigating and interacting with maps > Selecting features and graphics > About building an SQL expression
Mapping and visualization > Navigating and interacting with maps > Selecting features and graphics > SQL reference File geodatabases store data