The ArcGIS 10 release brought improvements to ArcCatalog, most notably its integration with ArcMap via the Catalog window. You can now directly access stand-alone ArcCatalog functionality while working with your data in ArcMap—a major convenience factor and productivity enhancement.
This week, many geographically dispersed American families are heading home for the holidays. Some organizations have geographically dispersed GIS data—scattered among different network locations, perhaps in randomly named folders, with lots of data stored (and duplicated) on individual desktops. This can make it a challenge both to find the data you need to work with and ensure that any new datasets you create are saved in the right location.
If this sounds familiar, you may welcome the Catalog window concepts of “home” (more specifically, the Home folder) and the default geodatabase. These concepts are specific to the Catalog window—there is no Home folder or default geodatabase when working with the stand-alone ArcCatalog application.
The Home Folder
The Home folder is the top item in the ArcMap Catalog window. The Home folder is the location of the current (open) map document, whose name displays in bold. When you open an existing map document, Home is the folder location where that map is stored. The first time you work in ArcMap 10, the Home folder for a new map document will be Documents > ArcGIS or My Documents > ArcGIS, depending on your Windows version. When you go to save that new map document, it will automatically be saved to this folder unless you specify a different location.
The Home folder is essentially a shortcut to your map. This is nice because if the data is stored in the same location as the map (a good idea when possible), you don’t have to navigate down through your folder connections to see the map layers’ source datasets and access their properties. Just go Home. The map document file (.MXD) is still in the same location on disk (you can navigate to it using a folder connection); the Home folder provides a quick way to view its location.
If you create a new map document one day and can’t find it the next, open Windows Explorer and check Documents > ArcGIS or My Documents > ArcGIS—there’s a good chance your map is there. You can also just start ArcMap. The Getting Started dialog box shows a list of recent maps you’ve worked with (another nice improvement in version 10).
The Default Geodatabase
In ArcGIS 10, every map document has a default geodatabase (as does every 3D scene document and globe document). By default, the default geodatabase is a file geodatabase named Default.gdb located in your Documents > ArcGIS or My Documents > ArcGIS folder (how many times can you say “default” in one sentence?). Like the active map document, the default geodatabase name displays in bold in the Catalog window.
The default geodatabase is not necessarily the geodatabase that contains the map’s source data (but it certainly can be). Rather, the default geodatabase is the geodatabase where feature classes will be saved when you export data or run geoprocessing tools. The default geodatabase can help you keep project data organized. When performing geoprocessing operations, for example, you will know the output location, which means you won’t have to waste time trying to figure out where your result data is.
In some cases, using Default.gdb as the default geodatabase for all your maps may make sense, but if you do a lot of geoprocessing or data exports, Default.gdb can quickly become too full to be a useful tool for organizing data.
For geoprocessing purposes, setting the default geodatabase is like setting the current workspace and scratch workspace without having to open the Environment Settings dialog box. Suppose you’re performing a buffer. When you’ve set the map’s default geodatabase, in the buffer tool dialog box, you just need to choose the input dataset, set the buffer distance and any other desired parameters, then click OK to run the tool.
Of course, you will still have to rename the output if you don’t like the name ArcGIS came up with. Using the Catalog window, you can quickly right-click the output feature class to rename it. The Catalog window is hugely convenient for tasks like this.
Continuing with the buffer example, if you have not set a default geodatabase for the map, ArcGIS saves the output feature class to Documents or My Documents > ArcGIS > Default.gdb unless you manually change the output path or specify a different scratch workspace in the geoprocessing environment settings. Those things are easy enough to do, but setting a “custom” default geodatabase is a time saver as well as a good way to keep your project data organized.
Setting a map’s default geodatabase is easy—right-click the geodatabase in the Catalog window and choose Make Default Geodatabase (you must have write access to the geodatabase). You can also set the default geodatabase in the Getting Started and New Document dialog boxes, or in the Map Document Properties dialog box—this is convenient when you’re creating a map document that others will use and you need to set map properties (such as creating a thumbnail or adding tags to support searching). You can change a map’s default geodatabase at any time.
To quickly see what or where the open map’s default geodatabase is, right-click the map in the Home folder and choose Locate Default Geodatabase or just click the Go To Default Geodatabase button at the top of the Catalog window. With either method, ArcGIS creates a folder connection to the location where the default geodatabase resides, and the connection is automatically expanded for you.