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 county_actual_expenditures_by_service_area_by table in this repository, by referencing it like:
"mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c:latest"."county_actual_expenditures_by_service_area_by"or in a full query, like:
SELECT
":id", -- Socrata column ID
"subtotal_expenditures", -- Sum of operating expenditures
"administration", -- Expenditures for policy & administration, central services and risk management services.
"county_environment_and", -- Expenditures for environmental quality, conservation and recreational services, animal control, educational services and county development.
"county", -- Name of the county for which the data is being displayed.
"geocoded_column", -- Primary latitude and longitude in decimal degrees for the county as provided by U.S. Geological Survey, 19810501, U.S. Geographic Names Information Systems (GNIS): U.S. Geological Survey, Reston, VA.
"operating_transfers_out", -- Expenditures associated with loans from budgeted funds to other than budgeted not repaid before the end of the fiscal year.
"capital_projects", -- Expenditures related to roadway construction, county conservation land acquisition, and other capital improvement projects.
"debt_service", -- Expenditures related to general obligation bonds or other long-term debt
"nonprogram_current", -- Expenditures related to refund of amounts recorded as revenues in prior years, pass-through grants, and budgeted expenditures related to county farm.
"government_services_to", -- Expenditures for representation services (e.g. election administration, local elections) and state administration services (e.g. motor vehicle registrations, driver license services, recording of public documents)
"mental_health_id_dd", -- Expenditures for services to persons with mental illness, persons with chronic mental illness, persons with intellectual disability, and persons with other developmental disabilities.
"physical_health_social", -- Expenditures for physical health services, services to the poor, services to military veterans, children's and family services, services to other adults, and the chemical dependency program.
"public_safety_and_legal", -- Expenditures for law enforcement, legal services, emergency services, assistance to District Court System, court proceedings, and juvenile justice administration.
"county_number", -- Iowa county code (1-99) associated with the county the expenditures shown are related to.
"fiscal_year", -- Fiscal year during which expenditures shown occurred. Fiscal year runs from July 1 to June 30.
"total_expenditures_other", -- Sum of Subtotal Expenditures, Operating Transfers Out and Refunded Debt/Escrow.
"refunded_debt_payments_to", -- Accounts for principal payments to refund debt and payments to escrow agents for defeased debt.
"roads_transportation", -- Expenditures for secondary roads administration and engineering, roadway maintenance, general roadway expenditures, and mass transit.
":@computed_region_3r5t_5243",
":@computed_region_wnea_7qqw",
":@computed_region_i9mz_6gmt",
":@computed_region_e7ym_nrbf",
":@computed_region_uhgg_e8y2"
FROM
"mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c:latest"."county_actual_expenditures_by_service_area_by"
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 mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c 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 mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c: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 mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9cCheckout 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 mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c:latestThis will download all the objects for the latest tag of mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c 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 mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c: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 mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c: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, mydata-iowa-gov/county-actual-expenditures-by-service-area-by-fxbr-vb9c is just another Postgres schema.