Introduction

This document lists all changes in the most recent major release, which is 7.3.0.

See the Recent Release Notes documents for the release notes for versions just prior to 7.3.0.

Change History repeats the list of user-visible modifications for this release and includes similar lists for all earlier releases.

Release 7.3.0

Release 7.3.0 is a major release with important new features.

Database internal format is unchanged from version the previous version (7.2.0)

Release 6.4.6 had a different internal format. All releases since then have the same internal format. This means version 6.5.0 through 7.2.1 repositories can be directly loaded into version 7.3.0 without upgrading. Note that backing up repositories before loading them into a new version is always recommended. Once a database has been used in a later release, it cannot be used in an earlier release regardless of whether or not the database format is the same. Upgrading is discussed in the Repository Upgrading document.

Version 7.3.0 Admin notes

This sections notes changes which may affect AllegroGraph administration, which includes managing users, dealing with passwords, and so on.

No admin notes for 7.3.0.

Version 7.3.0 Programmer notes

This section notes changes which may affect how certain code or operations work compared to earlier releases. These are emphasized here because the changes may be unexpected. The complete list of user-visible changes below also mentions these changes in a shorter format.

Version 7.3.0 user visible changes

This section lists changes in the current release. See the Change History for a list of changes in all earlier releases.

AllegroGraph Server: General Changes

agtool --output option replaced by --output-format.

--output-format is more descripting. The affected agtool commands include:

--output can still be used but will trigger a deprecation warning.

Rfe16785: Deprecate --results-format in favor of --output-format

The command-line interface for agtool query has a new argument, --output-format for specifying the desired output format, replacing --results-format. --output-format is the argument used by all agtool commands. Here is a sample call: 

agtool query <repo> query.rq --output-format sparql-json

The old argument can still be used but will trigger a deprecation warning.

Rfe16780 - Support for using AWS session tokens with agtool

New --aws-session-token command-line argument argument was added to the agtool commands that support interacting with AWS S3 (agtool export, agtool load and agtool archive). The session token value can also be read automatically from the configuration files. See Temporary credentials in the agtool document.

HTTP Client

No significant changes.

SPARQL

Rfe16766 - New query option to print query execution error backtraces

The logBacktraceOnQueryFailure causes debugging information to be printed to the log when errors occur when executing a query. While this information is rarely useful to the user, it may be useful when contacting AllegroGraph support.

Rfe16761 - New query options for profiling query execution

New query options profileQuery and profileOutputFormat can cause profile data to be written the the AllegroGraph log. This is useful when a query seems to take longer than expected. See Query execution options in SPARQL Reference.

Bug26683 - Incorrect results with duplicate blank nodes in patterns

SPARQL queries with patterns containing duplicate blank nodes, for example 

SELECT * { _:x ?p _:x }

could return incorrect solutions where the values corresponding to the blank nodes were not the same. This has been fixed.

Bug26629 - Errors in GROUP expressions with unknown variables on MJQE

SPARQL queries with unknown variables in a singleton complex GROUP expression, for example 

PREFIX franzOption_engine: <franz:mjqe>  
 
SELECT (SAMPLE(1) AS ?foo) { ?s ?p ?o }  
GROUP BY CONCAT(\"bar\", ?bar)

used to fail with the error message 

Received signal number 7 (Bus error)

This has been fixed and now the result of evaluating such an expression is assumed to be UNDEF, and the type error warning is reported alongside the unknown variables warning.

Bug26627 - Some SPARQL query warnings may cause obscure print errors

Certain query warnings, for example repeated projected variables like in the following query 

SELECT ?s ?s ?o { ?s ?p ?o }

are generated during parsing and trying to send such a query in a parsed form to a remote triple store or a distributed triple store shard may cause errors like 

Unable to print  
#<db.agraph.sparql.parser:warn-repeated-projected-variables-ignored  
  @ #x10012f443b2>  
readably and *print-readably* is true.

This has been fixed.

Bug26621 - SPARQL ORDER clause might not work when GROUP present

SPARQL queries with both GROUP and ORDER clauses could return results in an incorrect order because ORDER clause expressions used to have no access to bindings in GROUP and SELECT clauses that defined during aggregation. This has been fixed.

Additionally, ordering now also works with non-aggregate variables: in such cases the order expression is wrapped in an implicit SAMPLE operation and a corresponding warn-implicit-sample-introduced query warning is reported.

Bug26616 - Allow using constant SPARQL expressions as aggregates

It should be possible in SPARQL to use constant expression assignments alongside aggregated variables, for example 

SELECT ?s ("constant" AS ?c)  
WHERE { ?s ?p ?o }  
GROUP BY ?s

but assignments likes these used to cause queries to fail with errors like 

All selected variables must be aggregates but ?c is not.

This has been fixed.

Changes to the Lisp API

Rfe16175: Unify run-sparql's rdf-format/results-format arguments

The run-sparql function's arguments rdf-format and results-format are deprecated in favor of the new output-format argument. The old arguments can still be used but will signal a deprecation warning.

Prolog

No significant changes.

Documentation

No significant changes.

Distributed AllegroGraph

No significant changes.

User-visible changes in earlier releases

See Release Notes for Recent Versions for changes in recent release and Change History for user-visible changes to all earlier releases.