Geodatabase

A geodatabase is Esri's container for GIS data. Esri's ArcGIS Pro documentation: "At its most basic level, an ArcGIS geodatabase is a collection of geographic datasets of various types held in a common file system folder, or a multiuser relational database management system such as IBM Db2, Microsoft SQL Server, Oracle, PostgreSQL, or SAP HANA." Esri calls it "the native data structure for ArcGIS and is the primary data format used for editing and data management."

It holds feature classes, tables, and rasters, along with the rules and relationships among them. See Feature Class.

Three types

• File geodatabase: "stored as multiple files in a folder with a .gdb extension," one file per dataset. Each dataset can grow to 1 TB by default, raisable to 4 or 256 TB. File geodatabases "are designed to be edited by a single user and do not support geodatabase versioning."
• Mobile geodatabase: one SQLite file with a .geodatabase extension. Esri says the file "can hold up to 2 TB of data," and its contents can be queried with SQL in other software.
• Enterprise geodatabase: stored in a relational database for many users at once, with support for version-based workflows. Esri says these "can be virtually unlimited in size and number of users."

Compared with shapefiles

Esri says file geodatabases "use about one-third of the feature geometry storage required by shapefiles" and outperform them "for operations involving attributes." A geodatabase can also carry domains, subtypes, topology, and relationship classes. A shapefile, by Esri's own description, stores "nontopological geometry." See Shapefile.

Esri's stated limits for a file geodatabase feature class or table are 65,534 fields and 2,147,483,647 rows.

BLM's data in geodatabases

BLM's MLRS mining claim layer is described in its metadata as an "Enterprise Geodatabase Feature Class" and names "File geodatabase" as its data format. The metadata also lists relationships to other tables, such as NLSDB_CSE_SHAPE_HIST.

Why it matters in mining claim research

A geodatabase keeps mining claim polygons, PLSS layers, and land status together with their field types, domains, and relationships intact, where a folder of loose files can drift out of step. Two practical points follow from Esri's descriptions. A file geodatabase is a folder of many files, so it has to be moved and shared whole. And because a file geodatabase is built for a single editor, several people editing the same mining claim data at once need an enterprise geodatabase or another arrangement.