Data Model


Storage Model


Graph / RDF

Query Interface

Custom API

SPARQL, RDFS++ Reasoning, Prolog. SPARQL is the query language of choice for modern triple stores. AllegroGraph's RDFS++ reasoning supports all the RDFS predicates and some of OWL's. Prolog is an alternative query mechanism for AllegroGraph. With Prolog, you can specify queries declaratively.

Query Compilation

Not Supported


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


Users can use Lisp or JavaScript to define stored procedures.


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.

System Architecture


Partition with Federation. AllegroGraph's federation mechanism and flexible triple store architecture combine to make it easy to connect multiple stores together and treat them as one. When a user creates an AllegroGraph federated repository, a virtual index of the constituent stores is created and maintained in the client session to facilitate intelligent query processing and maximum performance.

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Tech Docs


Franz, Inc.

Country of Origin


Start Year


Project Type


Written in


Supported languages

C#, Clojure, Java, Lisp, Perl, Python, Ruby, Scala

Operating Systems

Linux, OS X, Windows