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Locators in a geodatabase in SQL Server

Locators in a geodatabase in SQL Server

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Locators are datasets that contain a snapshot of the reference data you would use for geocoding. It contains information on how an address is standardized, the searching methods used for address matches, and the type of information that is returned when there is a match. For more information on how locators are created and used, see the topics in "Building an address locator" in this help system. You can begin with the Defining the address locator components.

Locators in ArcCatalog

When you connect to your geodatabase in ArcCatalog, if you have created an address locator in your geodatabase, it would appear in the Catalog tree as shown below:

Address locator in ArcCatalog (SQL Server)

Locators in a SQL Server DBMS

When a new locator is created, a corresponding locator dataset table is created in the geodatabase. The locator dataset table contains a snapshot of the locator’s reference data, which includes all the attribute and shape information needed for geocoding stored in a format optimized for quick information search and retrieval.

After a new locator is created, it does not use the original reference data; it refers to the locator dataset table.

Locator dataset table names are the same as locator names but suffixed with _lox. If the locator name contains spaces, the spaces will be replaced with an underscore in the locator dataset table name.

The locator dataset table is used as a way to persist a collection of binary data blocks (similar to files) in a database.

NOTE: You should not modify the contents of the locator dataset table.

<locator_name>_lox

When you create a locator, ArcSDE reads geocoding specific attributes from the reference feature classes, organizes the data in an efficient proprietary binary structure, and stores a snapshot of the reference data in the locator dataset table. Thus, after the locator is created, it does not use the original reference data but only refers to the locator dataset table. As specified by the EmbedGeocodingRules locator property, the locator may also store a copy of its geocoding rule files in its geocoding index table.

The locator dataset table is used as a way to persist a collection of binary data blocks (similar to files) in a database. You should not modify the contents of the locator dataset table.


Field name Field type Description
fileid int ID of the internal geocoding index data block
segid int ID of a subsection (segment) of the internal geocoding index data block
data image Binary data of the subsection (segment) of the internal geocoding index data block

Click the following link to see the tables in the DBMS involved in a locator. In this example, the CITY_STREETS_LOX table is the locator dataset for the streetranges locator. The dashed lines indicate an implicit relationship between tables. You will need Adobe Acrobat Reader to open the file.

SQL Server locator diagram

Another example of the tables that make up a locator can be seen by clicking the link below. In this example, a geodatabase contains a STREET feature class that represents street centerlines for a particular geographic area such as a city. In addition to the geometry for the street centerlines, the STREET feature class contains attributes for the address ranges that can be found along the street and the components of the street name. The table schema required to store a locator to allow address geocoding on this feature class is shown below.

Locator schema example

Locators in an XML document

At present, locators are not supported in XML documents. Therefore, if you have locators in your geodatabase, export your geodatabase to an XML workspace document, then import the XML workspace document to another database, you will have to re-create the locators.