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 vehicle_snowmobile_and_boat_registrations table in this repository, by referencing it like:
"ny-gov/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt:latest"."vehicle_snowmobile_and_boat_registrations"or in a full query, like:
SELECT
":id", -- Socrata column ID
"zip", -- A code that identifies a specific geographic mail delivery area. ZIP Codes can represent an area within a foreign country, a state, or a single building or company that has a very high mail volume. The zip code appears in the last line of the address on a mail piece. Example: 12345
"reg_expiration_date", -- The date when the registration expires.
"scofflaw_indicator", -- Indicates if a parking or red light scofflaw stop is in effect. (Y/N).
"revocation_indicator", -- Indicates if a revocation is in effect. (Y/N).
"maximum_gross_weight", -- The maximum weight that a commercial vehicle is permitted to carry.
"county", -- The New York State county name that is the county of residence or use.
"body_type", -- The body type of a vehicle. (see the complete list of body types at the end of the data dictionary)
"fuel_type", -- The fuel type of a vehicle.
"state", -- The official USPS abbreviation for the name of a mailing state, U.S. territory, Canadian Province, Commonwealth or armed forces ZIP Code designation. If APO/FPO/DPO, then the state abbreviation will be “AA,” “AE,” or “AP.”
"suspension_indicator", -- Indicates if a suspension is in effect. (Y/N).
"model_year", -- The manufacturer model year of vehicle.
"city", -- A city name for mailing purposes; appears in the last line of an address on a mail piece.
"color", -- The color of the vehicle. This is the DMV code not the NCIC code. (see the color codes at the end of the data dictionary)
"make", -- The DMV code for the make of a vehicle that appears on the registration. The DMV make code is the first 5 letters of the vehicle’s make name. If the vehicle make is more than one word, the make code is the first 2 letters of the first two words with a slash in between. (Examples, CHEVR, HA/DA)
"vin", -- The Vehicles Identification Number as assigned by the vehicle manufacturer or by NYS DMV if the original VIN was compromised.
"unladen_weight", -- The weight of a passenger vehicle without any load.
"registration_class", -- An alpha code that is used to classify the registration. (see complete list of registration classes at the end of the data dictionary)
"record_type", -- The type of vehicle. BOAT = Boat; SNOW = Snowmobile; TRL = Trailer; VEH = All other vehicles
"passengers", -- The number of passengers that a for-hire vehicle can transport, excluding the driver.
"reg_valid_date" -- The date DMV issued the most recent registration document.
FROM
"ny-gov/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt:latest"."vehicle_snowmobile_and_boat_registrations"
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/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt 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/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt: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/vehicle-snowmobile-and-boat-registrations-w4pv-hbktCheckout 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/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt:latestThis will download all the objects for the latest tag of ny-gov/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt 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/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt: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/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt: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/vehicle-snowmobile-and-boat-registrations-w4pv-hbkt is just another Postgres schema.