Cloning the FERC Form 1 DB¶
FERC Form 1 is… special.
The Form 1 data is published in a particularly inaccessible format (proprietary binary FoxPro database files), and the data itself is unclean and poorly organized. As a result, very few people are currently able to use it at all, and we have not yet integrated the vast majority of the available data into PUDL. This also means it’s useful to just provide programmatic access to the bulk raw data, independent of the cleaner subset of the data included within PUDL.
To provide that access, we’ve broken the
down into two distinct steps:
Clone the entire FERC Form 1 database from FoxPro into a local file-based
sqlite3database. This includes 116 distinct tables, with thousands of fields, covering the time period from 1994 to the present.
Pull a subset of the data out of that database for further processing and integration into the PUDL data packages and
If you want direct access to the original FERC Form 1 database, you can just do the database cloning, and connect directly to the resulting database. This has become especially useful since Microsoft recently discontinued the database driver that until late 2018 had allowed users to load the FoxPro database files into Microsoft Access.
In any case, cloning the original FERC database is the first step in the PUDL
ETL process. This can be done with the
ferc1_to_sqlite script (which is an
entrypoint into the
pudl.convert.ferc1_to_sqlite module) which is
installed as part of the PUDL Python package. It takes its instructions from a
YAML file, an example of which is included in the
settings directory in
your PUDL workspace. Once you’ve created a datastore you can
try this example:
$ ferc1_to_sqlite settings/ferc1_to_sqlite_example.yml
This should create an SQLite database that you can find in your workspace at
sqlite/ferc1.sqlite By default, the script pulls in all available years of
data, and all but 3 of the 100+ database tables. The excluded tables
unreadable binary data, and increase the overall size of the database by a
factor of ~10 (to ~8 GB rather than 800 MB). If for some reason you need access
to those tables, you can create your own settings file and un-comment those
tables in the list of tables that it directs the script to load.
This script pulls all of the FERC Form 1 data into a single database,
but FERC distributes a separate database for each year. Virtually all
the database tables contain a
report_year column that indicates which
year they came from, preventing collisions between records in the merged
multi-year database. One notable exception is the
table, which maps
respondent_id to the names of the respondents. For
that table, we have allowed the most recently reported record to take
precedence, overwriting previous mappings if they exist.
Sadly, the FERC Form 1 database is not particularly… relational. The only
foreign key relationships that exist map
respondent_id fields in the
individual data tables back to
f1_respondent_id. In theory, most of the
data tables use
report_prd as a composite primary key (According to
this FERC Form 1 database schema from 2015.
In practice, there are several thousand records (out of ~12 million), including some in almost every table, that violate the uniqueness constraint on those primary keys. Since there aren’t many meaningful foreign key relationships anyway, rather than dropping the records with non-unique natural composite keys, we chose to preserve all of the records and use surrogate auto-incrementing primary keys in the cloned SQLite database.