The goal of the ProvSQL project is to add support for (m-)semiring provenance and uncertainty management to PostgreSQL databases, in the form of a PostgreSQL extension/module/plugin. It is work in progress at the moment.
The ProvSQL system currently supports proper management of provenance attached to SQL queries, in the form of a provenance circuit, suitable both for regular Boolean provenance, arbitrary semiring provenance, with or without monus (m-semiring), in the free m-semiring, or specialized to any m-semiring of choice. It also supports where-provenance and probability computation from the provenance, through a variety of methods.
The following SQL queries are currently supported.
- Regular SELECT-FROM-WHERE queries (aka conjunctive queries with multiset semantics)
- JOIN queries (regular joins only; outer, semijoins, and antijoins are not currently supported)
- SELECT queries with nested SELECT subqueries in the FROM clause
- GROUP BY queries (without aggregation)
- SELECT DISTINCT queries (i.e., set semantics)
- UNION's or UNION ALL's of SELECT queries
- EXCEPT of SELECT queries
As an alternative to a ProvSQL installation (see below), you can try a demonstration version of ProvSQL (full-featured, except for circuit visualization) as a Docker container. To deploy it, once Docker CE is installed, simply run:
docker run inriavalda/provsqldemo
By following the instructions, you will be able to connect to the PostgreSQL server within the container using a PostgreSQL client, and to use a Web interface for simple visualization of where-provenance.
Prerequisites for installation
An install of PostgreSQL >= 9.5. The extension has currently been tested with versions from 9.5 to 10 (inclusive) of PostgreSQL, under Linux and Mac OS X (if the extension does not work on a specific version or operating system, a bug report is appreciated).
A compilation environment for PostgreSQL, including the
maketool, a C compiler (both can be obtained on Debian-based Linux distributions from the virtual
build-essentialpackage), and the headers for your PostgreSQL version (as can be obtained for instance from the
postgresql-server-dev-9.xpackage on Debian-based systems, or from the
postgresqlpackage on the Homebrew package manager for Mac OS X).
uuid-osspextension for PostgreSQL (on Debian-based systems, it is found in the
postgresql-contrib-9.xpackage for PostgreSQL version 9.x, and is installed automatically for PostgreSQL version 10; on Homebrew, in the
Optionally, for probability computation, any or all of the following software:
dsharp, from https://bitbucket.org/haz/dsharp
To be used, an executable with the name of this software must be available in the PATH of the PostgreSQL server user (e.g., in
Optionally, for circuit visualization, the following software:
graphviz, for production of PDF circuits (
evince, for visualization of PDF files
Both can be obtained as packages in common Linux distributions.
Compile the code with
make. If you have several installed versions of PostgreSQL, you can change the version the module is compiled against by changing the reference to
pg_configin the Makefile.
Install it in the PostgreSQL extensions directory with
make install(run as a user with rights to write to the PostgreSQL installation directories).
Add the line
shared_preload_libraries = 'provsql'
postgresql.confconfiguration file (on Linux systems, it should be in
/etc/postgresql/VERSION/main/postgresql.conf) and restart the PostgreSQL server (e.g., with
service postgresql restarton systemd-based distributions). This is required because the extension includes hooks.
Testing your installation
You can test your installation by running
make installcheck as a
PostgreSQL administrator user. If you do not want to run this as the
default administrator user, you can make yourself a PostgreSQL
ALTER USER your_login WITH SUPERUSER. This assumes that
your_login is a PostgreSQL user: on Debian-based Linux distributions, you
can ensure this by running the command
createuser your_login as the
Note that the tests that depend on external software (
dot) will fail if no executable of that name can be found.
For circuit visualization, the database server will attempt to launch
on a local X window server (
:0). You can authorize the display of such windows
You can use ProvSQL in any PostgreSQL database by loading the
provsql extension. See the file setup.sql
for an example on how to do this.
You then need to add provenance to an existing table using the
provsql.add_provenance(regclass) user-defined function.
See add_provenance.sql for an example.
The table will have an extra
provsql column added. This column
is handled in a special way and always represents, in query results, the
provenance of each tuple as a UUID.
See the other examples in test/sql for other use cases.
A demonstration of the ProvSQL system is available as a video, on https://youtu.be/iqzSNfGHbEE?vq=hd1080
An unpublished article describing this demonstration is available at http://pierre.senellart.com/publications/senellart2018provsql.pdf
You can uninstall ProvSQL by running
make uninstall (run as a user with
rights to write to the PostgreSQL installation directories).
ProvSQL is provided as open-source software under the MIT License. See LICENSE.
Pierre Senellart email@example.com
Bug reports and feature requests are preferably sent through the Issues feature of GitHub.