Using AUCQL's COLLAPSE Operation

Using AUCQL's COLLAPSE Operation
A Query Language for Semistructured Data with Metadata Properties

Home
Publications
Prototype
Examples
	The DB
	Start
	Defaults
	Match
	Property
	Collapse
	Coalesce
	Security
	Time

Curtis Dyreson
	Home
	Publications
	Projects
	Software
	Demos
	Teaching
	Contact me

Syntax

The general form of a COLLAPSE is given below.

COLLAPSE(variable)

COLLAPSE collapses a path, represented by the variable, to a single edge. How each property in the path is collapsed depends on the semantics of the property.

Collapsing the NAME property

The NAME property is collapsed by concatenating names.

The names of paths to all nodes.:
SELECT *
FROM   (SECURITY: 'over 18, paid, subscriber')* All,
       COLLAPSE(All) Collapsed,
       PROPERTY(NAME, Collapsed) Names;
Note that the NAME of a root edge is missing ('@').

The PROPERTY operation does an implicit COLLAPSE, so the following query is effectively equivalent to the one given above.

The names of paths to all nodes redux.:

SELECT *
FROM   (SECURITY: 'over 18, paid, subscriber')* All,
       PROPERTY(NAME, All) Names;

Collapsing security

The SECURITY property is collapsed by determining which certificates are needed.

The security on paths to all nodes.:
SELECT *
FROM   (SECURITY: 'over 18, paid, subscriber')* All,
       PROPERTY(NAME, All) Name,
       PROPERTY(SECURITY, All) Security;
Note that manyùnodes are reachable without any security.

Collapsing transaction time

The TRANSACTION TIME property is collapsed using temporal intersection.

The security and transaction time for all nodes.:

SELECT *
FROM   (SECURITY: 'over 18, paid, subscriber')* All,
       PROPERTY(NAME, All) Name,
       PROPERTY(SECURITY, All) Security,
       PROPERTY(QUALITY, All) Quality,
       PROPERTY(TRANSACTION_TIME, All) TT;

Other properties

Other properties, such as QUALITY, are also collapsed.

The security, transaction time, and quality for all nodes.:

SELECT *
FROM   (SECURITY: 'over 18, paid, subscriber')* All,
       PROPERTY(NAME, All) Name,
       PROPERTY(SECURITY, All) Security,
       PROPERTY(QUALITY, All) Quality,
       PROPERTY(TRANSACTION_TIME, All) TT;

E-mail questions or comments to Curtis.Dyreson at usu.edu