Query the Data Delivery Network

The 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 distribution_of_funds_to_nonentitlement_units_of table in this repository, by referencing it like:

"mydata-iowa-gov/distribution-of-funds-to-nonentitlement-units-of-yp54-t3rh:latest"."distribution_of_funds_to_nonentitlement_units_of"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "first_tranche_total_payment", -- Sum total of first tranche allocation and reallocation payments
    "first_tranche_allocation", -- Funds allocated to the city as part of the first tranche in 2021
    "adjusted_full_allocation", -- Sum of original allocation and reallocation adjustment.
    "original_allocation", -- Allocation the city is eligible to receive from first and second tranche based on the following formula: (Total population of the NEU/Total population of all eligible NEUs) X Aggregate state NEU payment
    "status", -- The city's status regarding NEU allocation.  Status is one of the following: Submitted - Participated, Submitted - Transfer to State, Reallocation - No Response, and Reallocation - Requested Transfer to NEUs
    "second_tranche_allocation_payment", -- Payment made to the city based on the second tranche allocation
    "first_tranche_reallocation_payment", -- Additional payment made as part of a reallocation of funds from the first tranche.  Reallocations were made in instances where a city remained unresponsive after reasonable efforts to contact them, or have declined the funding.  
    "first_tranche_allocation_payment", -- Payment made to the city based on the first tranche allocation
    "population_estimate_2019", -- Population estimate used for allocating funds
    "city_name", -- Name of the city being allocated funding
    "neu_recipient_number", -- Unique identifier created for the city
    "reallocation_adjustment" -- Reallocation adjustment made based on the status of the city.
FROM
    "mydata-iowa-gov/distribution-of-funds-to-nonentitlement-units-of-yp54-t3rh:latest"."distribution_of_funds_to_nonentitlement_units_of"
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/distribution-of-funds-to-nonentitlement-units-of-yp54-t3rh with SQL in under 60 seconds.

This repository is an "external" repository. That means it's hosted elsewhere, in this case at mydata.iowa.gov. When you querymydata-iowa-gov/distribution-of-funds-to-nonentitlement-units-of-yp54-t3rh:latest on the DDN, we "mount" the repository using the socrata mount handler. The mount handler proxies your SQL query to the upstream data source, translating it from SQL to the relevant language (in this case SoQL).

We also cache query responses on the DDN, but we run the DDN on multiple nodes so a CACHE_HIT is only guaranteed for subsequent queries that land on the same node.

Query Your Local Engine

bash -c "$(curl -sL https://github.com/splitgraph/splitgraph/releases/latest/download/install.sh)"

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 (like this repository), 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, where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.

Mounting Data

This repository is an external repository. It's not hosted by Splitgraph. It is hosted by mydata.iowa.gov, and Splitgraph indexes it. This means it is not an actual Splitgraph image, so you cannot use sgr clone to get the data. Instead, you can use the socrata adapter with the sgr mount command. Then, if you want, you can import the data and turn it into a Splitgraph image that others can clone.

First, install Splitgraph if you haven't already.

Mount the table with sgr mount

sgr mount socrata \
  "mydata-iowa-gov/distribution-of-funds-to-nonentitlement-units-of-yp54-t3rh" \
  --handler-options '{
    "domain": "mydata.iowa.gov",
    "tables": {
        "distribution_of_funds_to_nonentitlement_units_of": "yp54-t3rh"
    }
}'

That's it! Now you can query the data in the mounted table like any other Postgres table.

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/distribution-of-funds-to-nonentitlement-units-of-yp54-t3rh is just another Postgres schema.