Data Management Terminology


  • Selects records from one or more data sources and copies the selected records to an existing table.

   Calculated Field

  • Takes information from one or more other fields and performs mathematical, date or string operations to provide new information. If necessary, the new information can simply be displayed as part of a query or report, or can be used to create an entirely new field that is part of the query (or report) but typically not part of the data table.

   Child Table

  • A table that is linked directly or indirectly to a primary or parent table in a set of tables; often in a many-to-one relationship (e.g. a child table of customer transactions is linked in a many-to-one relationship with a parent table containing customers). 


  • Data restrictions specified in a database; rules that determine what values the field to the table can assume.


  • Coordinate reference system. Inculdes datum, elipsoid, and projection

   Data Type

  • Every field in every table in a database must be declared as a specific type of data with defined parameters and limitations (e.g. numeric, character or text, date, logical, etc.), known as a data type.


  • European Petroleum Survey Group. A short numerical code to represent the CRS. Make up most SRIDs

   Escape Character

  • Escape characters are part of the syntax for many programming languages, data formats and communication protocols. For a given alphabet an escape character's purpose is to start character sequences (so named escape sequences) which have to be interpreted differently from the same characters occurring without the prefixed escape character. An escape character may not have its own meaning, so all escape sequences are of 2 or more characters

   File share 

  • Distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. File sharing may be achieved in a number of ways. Common methods of storage, transmission and dispersion include manual sharing utilizing removable media, centralized servers on computer networks, World Wide Web-based hyperlinked documents, and the use of distributed peer-to-peer networking.

 File store

  • File-level computer data storage connected to a computer network providing data access to a heterogeneous group of clients. Not only operates as a file server, but is specialized for this task either by its hardware, software, or configuration of those elements.

   Flat File

  • A collection of data records having minimal structure. Because the flat file system has no metadata, applications written to work with flat files must contain the equivalent of the metadata as part of the application itself.

   Foreign Key

  • A column or group of columns in a table that corresponds to or references a primary key in another table in the database. A foreign Key need not itself be unique, but must uniquely identify the field or fields in the table that the key references.

   Geography Data type

  • represents data in a round-earth coordinate system. Ex. Longitutde and latitude coordinates

   Geometry Data type

  • represents data in a Euclidean (flat) coordinate system. Or projected coordinate system. Ex. UTM


  • Graphical User Interface (sometimes pronounced "gooey"), is a type of interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces, which require commands to be typed on the keyboard.


  • Describe organizational structures and logical parent-child relationships within the data (e.g. global corporation => country => region => district => market => individual store).



  • Describes a complete database environment, including the RDBMS software, table structure, stored procedures and other functionality. It is most commonly used when administrators describe multiple instances of the same database.

 Natural Key

  • A unique identfier for each row of data that uses a more than one coulmn 

   Nested Query

  • A statement that contains one or more sub queries.


  • A telecommunications network that allows computers to exchange data. In computer networks, networked computing devices pass data to each other along data connections. Data is transferred in the form of packets. The connections (network links) between nodes are established using either cable media or wireless media. 


  • If a field contains a data item, that has a specific value. A field that does not contain a data item is said to have a null value. In a numeric field, a null value is not the same as a value of zero; in a character field, a null value is not the same as a blank -- both the numeric zero and blank character are definite values. A null value indicates that the that the field’s value is undefined -- it's value is not known.


  • Open Database Connection


  • Open Geospatial Consortium is a non-profit standards organization focused on geospatial data

 Parent Table

  • The table to which a child table is linked; often in a one-to-many relationship (e.g. a parent table of customers is linked in a one-to-many relationship with a child table containing customer transactions)


  • port numbers are required to allow Microsoft SQL Server to communicate over a firewall

 Primary Key

  • A unique identfier for each row of data


  • Logical question of databases and information systems


  • Relational database management system


  • Regular Expression is a sequence of characters that forms a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. "find and replace"-like operations

 User Schema

  • A user schema is separate entity within the database.  A schema can be owned by a user, a role, or a group

 Spatial Query

  • The use of geometry data types such as points, lines and polygons and that these queries consider the spatial relationship between these geometries. i.e. intersect, touches, contains, etc.

 Special Characters

  • Some characters have special meanings when they are used in a URL or in an XML document, and must be encoded properly for these meanings to take effect. 


  • Structured Query Language is a special-purpose programming language designed for managing data held in a relational database management system (RDBMS).Originally based upon relational algebra and tuple relational calculus, SQL consists of a data definition language and a data manipulation language. The scope of SQL includes data insert, query, update and delete, schema creation and modification, and data access control


  • Spatial Reference System Identifier is a unique value used to unambiguously identify projected, unprojected, and local spatial coordinate system definitions. These coordinate systems form the heart of all GIS applications.

 ST Object

  • Returns a geometry data type from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation augmented with any Z (elevation) and M (measure) values

 Sub Query

  • A query contained within another query, usually hierarchically larger in scope.


  • A tuple is a data structure that has a specific number and sequence of elements. An example of a tuple is a data structure with three elements (known as a 3-tuple or triple) that is used to store an identifier such as a person's name in the first element, a year in the second element, and the person's income for that year in the third element. 


  • A stored query that can be read just like a table without storing any extra data. A virtual table.


  • Well Known Text  is a text markup language for representing vector geometry objects on a map, spatial reference systems of spatial objects and transformations between spatial reference systems.