SDB is a Jena storage module that uses SQL databases for RDF storage.
See [1] for documentation. It uses a custom database schema to store
RDF; it is not a general SQL-to-RDF mapping layer.
The supported databases are: Oracle, Microsoft SQL Server, DB2,
PostgreSQL, MySQL, Apache Derby, H2, HSQLDB. Only Derby and HSQLDB are
tested in the development build process.
Both Oracle and IBM corporations provide commercial RDF solutions using
Jena that are completely unrelated to SDB.
TDB is faster, more scalable and better supported than SDB but there can
be reasons why an SQL-backed solution is appropriate.
There is no active development or maintenance of SDB from within the
committer team; no committers use SDB and it imposes a cost to the team
to generate separate releases. We're not receiving patches contributed
to JIRA items for bugs.
We are proposing:
1/ moving it into the main build so it will be part of the main
distribution with limited testing.
2/ marking it as "under review / maintenance only".
It will not be treated as something that can block a release, nor for
any significant length of time, stop development builds.
It may be pulled from the main build, and from a release, at very short
notice.
If moved out, the source code will still be available but no binaries
(releases or development builds) will be produced.
What would change SDB's status is care and attention. There are ways to
enhance it, for example, pushing the work of filters into the SQL
database, where possible, to improve query performance.
Andy
[1] http://jena.apache.org/documentation/sdb/index.html
