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_economic_and_community_development table in this repository, by referencing it like:
"ct-gov/department-of-economic-and-community-development-t2xi-dmhg:latest"."department_of_economic_and_community_development"or in a full query, like:
SELECT
":id", -- Socrata column ID
"geocoded_column_zip",
"geocoded_column_city",
"geocoded_column_address",
"parcel_count", -- Number of parcels of land that contain sites go be remediated (not necessarily contiguous)
"statutory_reference", -- Location of legal authority for which the funding and program requirements are provided.
"total_project_cost", -- Total amount of DECD and non-DECD funding being used to complete the project.
"other_project_funds", -- Amount of non-DECD funding for the project.
"total_assistance", -- Total amount of DECD funding being provided to the Applicant.
"loan_amount", -- Amount of DECD loan funding being provided to the Applicant.
"grant_amount", -- Amount of DECD grant funding being provided to the Applicant.
"contract_execution_date", -- Date financial assistance agreement was signed by Attorney General and/or DECD Commissioner.
"project_name", -- Name of the property/project that is associated with the financial assistance being provided.
"project_municipality", -- Location where project or economic activity is occurring.
"project_address", -- Location where project or economic activity is occurring.
"applicant_state", -- Applicant location.
"applicant_address", -- Applicant location.
"applicant", -- Entity receiving financial assistance from DECD.
"fiscal_year", -- Based on State Fiscal Year that the contract was signed
"remediated_acreage", -- Total acreage of the parcel that contains the contaminated site
"funding_source", -- Name of State financing program being used for this project.
"applicant_zip_code", -- Applicant location.
"project_zip_code", -- Location where project or economic activity is occurring.
"geocoded_column",
"applicant_municipality", -- Applicant location.
"project_county",
"geocoded_column_state",
"count" -- DECD data management tool.
FROM
"ct-gov/department-of-economic-and-community-development-t2xi-dmhg:latest"."department_of_economic_and_community_development"
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 ct-gov/department-of-economic-and-community-development-t2xi-dmhg 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 ct-gov/department-of-economic-and-community-development-t2xi-dmhg: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 ct-gov/department-of-economic-and-community-development-t2xi-dmhgCheckout 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 ct-gov/department-of-economic-and-community-development-t2xi-dmhg:latestThis will download all the objects for the latest tag of ct-gov/department-of-economic-and-community-development-t2xi-dmhg 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 ct-gov/department-of-economic-and-community-development-t2xi-dmhg: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 ct-gov/department-of-economic-and-community-development-t2xi-dmhg: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, ct-gov/department-of-economic-and-community-development-t2xi-dmhg is just another Postgres schema.