Query the Data Delivery Network
Query the DDNThe easiest way to query any data on Splitgraph is via the "Data Delivery Network" (DDN). The DDN is a single endpoint that speaks the PostgreSQL wire protocol. Any Splitgraph user can connect to it at data.splitgraph.com:5432 and query any version of over 40,000 datasets that are hosted or proxied by Splitgraph.
For example, you can query the department_of_motor_vehicles_registration table in this repository, by referencing it like:
"ny-gov/department-of-motor-vehicles-registration-s2dd-yksa:latest"."department_of_motor_vehicles_registration"or in a full query, like:
SELECT
":id", -- Socrata column ID
"state", -- This is from the mailing address of the registration.
"hull_material", -- Describes the vessel’s hull. This is applicable only to records where registration Class = “MOTORBOATS”.
"exported", -- The date when the record was exported from DMV’s files. Transactions having an Effective Date from more than a week prior to the Exported Date were re-exported because the registration address changed.
"fuel", -- The primary fuel type that propels the vehicle. If the vehicle is battery assisted, and can use a nonelectric fuel, the value is the non-electric fuel. It is also null on MOTORBOAT, SNOWMOBILE ,DEALER and TRANSPORTER registrations. Caution: Fuel types are manually entered and subject to error.
"propulsion", -- Describes the vessel’s primary propulsive mechanism. This is applicable only to records where registration Class = “MOTORBOATS”.
"displacement_or_horsepower", -- Describes a snowmobile’s engine. This is applicable only to records where registration Class = “SNOWMOBILE”. Units are cubic centimeters and horsepower; however, DMV does not distinguish whether the number describes horsepower or displacement. Further, there are numerous definitions for “horsepower”. The reader must infer the most likely meaning of this number, record by record.
"registration_class", -- NYS Vehicle and Traffic Law defines registration classes. The registrant’s organization, the vehicle’s characteristics and the registrant’s use case for the vehicle determine the registration class. This attribute is never null. Details are at https://dmv.ny.gov/registrations-0
"georeference", -- Open Data platform-generated geocoding information from supplied address components. Point-type location is the centroid of the address components provided and does not reflect a specific address if the street address component is not provided. Point-type location is supplied in "POINT (<geocoded longitude> <geocoded latitude>)" format.
"vehicle_identification_number", -- This is a unique identifier for a vehicle, boat, motorcycle, snowmobile or trailer, also known as “VIN”. It is null on DEALER and TRANSPORTER registrations because they are used on the road with a changing assortment of inventory. Caution, a small number of erroneous VINs and nulls have been recorded.
"body_type", -- NYS DMV’s description of the vehicle’s configuration. It is null on DEALER and TRANSPORTER registrations. Caution: Body types are manually entered and subject to error.
"zip_code", -- This is from the mailing address of the registration.
"county_of_use", -- Where the vehicle or vessel is primarily used. This is applicable only to records where registration Class = “MOTORBOATS” or “SNOWMOBILE”.
"registration_expiration", -- The date when the registration will expire. It can be null. Registrations for State and Political Subdivisions do not expire. Some registration classes have fixed, annual expiration dates. They will appear in groups.
"effective_date", -- The date when the registration record became effective. INTERNATIONAL REGISTRATION PLAN registrations are often post-dated.
"length", -- The distance, in feet, from vessel bow to stern. This is applicable only to records where registration Class = “MOTORBOATS”.
"maximum_gross_vehicle_weight", -- The vehicle weight plus the carrying capacity determines the maximum gross vehicle weight. DMV records either weight or seats on a registration. It is also null on MOTORBOAT, SNOWMOBILE, DEALER and TRANSPORTER registrations.
"registrant", -- NYS DMV’s categorization of the registrant. It can be null when the value is not readily apparent from the configuration of the Registrant’s name.
"use", -- Describes the vessel’s use case. This is applicable only to records where registration Class = “MOTORBOATS” or “SNOWMOBILE”. When Use = “DEALER” consult the notes for other attributes that apply to DEALER and TRANSPORTER registrations.
":@computed_region_kjdx_g34t", -- This column was automatically created in order to record in what polygon from the dataset 'Counties' (kjdx-g34t) the point in column 'georeference' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
"model_year", -- The vehicle manufacturer’s indication of which year the vehicle was manufactured. It is null on DEALER and TRANSPORTER registrations. Caution, a small number of erroneous model years and nulls have been recorded.
"make_code", -- NYS DMV’s abbreviation for the vehicle manufacturer. It is null on DEALER and TRANSPORTER registrations. Caution: Make codes are manually entered and subject to error. For example, a VIN series may have a make code = “CHEVR” on most records and “CHEVY” on a handful. “OTHER” and “HOMEM” are sometimes recorded in lieu of available manufacturers’ codes.
"transaction", -- NYS DMV’s description of the transaction executed for the registrant.
"residence_county", -- This is from the residence address of the registrant.
":@computed_region_wbg7_3whc", -- This column was automatically created in order to record in what polygon from the dataset 'New York Zip Codes' (wbg7-3whc) the point in column 'georeference' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_yamh_8v7k", -- This column was automatically created in order to record in what polygon from the dataset 'NYS Municipal Boundaries' (yamh-8v7k) the point in column 'georeference' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
"city", -- This is from the mailing address of the registration.
"seats", -- Total adult seating capacity including the driver. DMV records either weight or seats on a registration. It is also null on MOTORBOAT, SNOWMOBILE , DEALER and TRANSPORTER registrations.
"cylinders" -- The number of cylinders in the engine. It is null on MOTORBOAT, SNOWMOBILE, DEALER and TRANSPORTER registrations. Caution: Cylinder counts are manually entered and subject to error.
FROM
"ny-gov/department-of-motor-vehicles-registration-s2dd-yksa:latest"."department_of_motor_vehicles_registration"
LIMIT 100;Connecting to the DDN is easy. All you need is an existing SQL client that can connect to Postgres. As long as you have a SQL client ready, you'll be able to query ny-gov/department-of-motor-vehicles-registration-s2dd-yksa with SQL in under 60 seconds.
Query Your Local Engine
bash -c "$(curl -sL https://github.com/splitgraph/splitgraph/releases/latest/download/install.sh)"Read the installation docs.
Splitgraph Cloud is built around Splitgraph Core (GitHub), which includes a local Splitgraph Engine packaged as a Docker image. Splitgraph Cloud is basically a scaled-up version of that local Engine. When you query the Data Delivery Network or the REST API, we mount the relevant datasets in an Engine on our servers and execute your query on it.
It's possible to run this engine locally. You'll need a Mac, Windows or Linux system to install sgr, and a Docker installation to run the engine. You don't need to know how to actually use Docker; sgrcan manage the image, container and volume for you.
There are a few ways to ingest data into the local engine.
For external repositories, the Splitgraph Engine can "mount" upstream data sources by using sgr mount. This feature is built around Postgres Foreign Data Wrappers (FDW). You can write custom "mount handlers" for any upstream data source. For an example, we blogged about making a custom mount handler for HackerNews stories.
For hosted datasets (like this repository), where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.
Cloning Data
Because ny-gov/department-of-motor-vehicles-registration-s2dd-yksa:latest is a Splitgraph Image, you can clone the data from Spltgraph Cloud to your local engine, where you can query it like any other Postgres database, using any of your existing tools.
First, install Splitgraph if you haven't already.
Clone the metadata with sgr clone
This will be quick, and does not download the actual data.
sgr clone ny-gov/department-of-motor-vehicles-registration-s2dd-yksaCheckout the data
Once you've cloned the data, you need to "checkout" the tag that you want. For example, to checkout the latest tag:
sgr checkout ny-gov/department-of-motor-vehicles-registration-s2dd-yksa:latestThis will download all the objects for the latest tag of ny-gov/department-of-motor-vehicles-registration-s2dd-yksa and load them into the Splitgraph Engine. Depending on your connection speed and the size of the data, you will need to wait for the checkout to complete. Once it's complete, you will be able to query the data like you would any other Postgres database.
Alternatively, use "layered checkout" to avoid downloading all the data
The data in ny-gov/department-of-motor-vehicles-registration-s2dd-yksa:latest is 0 bytes. If this is too big to download all at once, or perhaps you only need to query a subset of it, you can use a layered checkout.:
sgr checkout --layered ny-gov/department-of-motor-vehicles-registration-s2dd-yksa:latestThis will not download all the data, but it will create a schema comprised of foreign tables, that you can query as you would any other data. Splitgraph will lazily download the required objects as you query the data. In some cases, this might be faster or more efficient than a regular checkout.
Read the layered querying documentation to learn about when and why you might want to use layered queries.
Query the data with your existing tools
Once you've loaded the data into your local Splitgraph Engine, you can query it with any of your existing tools. As far as they're concerned, ny-gov/department-of-motor-vehicles-registration-s2dd-yksa is just another Postgres schema.