Data Model

Graph

Storage Model

Custom

Graph / RDF

Query Interface

Custom API

RESTful HTTP API, SPARQL

Query Compilation

Not Supported

Views

Virtual Views

A logic view is offered by Prolog. Query can support match graph ( contains multiple triples), join, filter, order, etc.

Isolation Levels

Snapshot Isolation

Every transaction sees a snapshot of the persistent database state as of the time when the transaction is started. During the transaction, it can change the persistent state without affecting the snapshot of others. When finishes, any updates made by concurrent transactions are visible.

Stored Procedures

Supported

JavaScript or Common Lisp

Logging

Logical Logging

When the commit operation of AllegroGraph returns, the database server will have written the updates made by the transaction to the transaction log and waited for the log I/O operation to finish. Transaction log files record all committed database changes (triple additions and deletions), along with some other information.

Storage Architecture

Disk-oriented

System Architecture

Shared-Nothing