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 iowa_pandemic_recovery_reporting_federal_funds table in this repository, by referencing it like:

"mydata-iowa-gov/iowa-pandemic-recovery-reporting-federal-funds-a5qe-4idi:latest"."iowa_pandemic_recovery_reporting_federal_funds"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "award_date", -- The date of the initial federal award or subsequent amendment
    "state_department", -- Name of the State department awarded the federal funds.
    "performance_end", -- The date on which effort related to the award ends or is completed, or, if applicable, when the emergency declaration ended.
    "state_dept_no", -- The three digit code used in the State Accounting System for the department who is the prime recipient of the award
    "duns_number", -- The unique 9-digit number assigned by Dun and Bradstreet (D&B) referred to as the DUNS® used in the Federal System for Award Management for the state agency on the award received.
    "federal_department", -- The name of the federal department responsible for the federal award.
    "record_id", -- Unique identifier for the record; concatenation of federal_award_number and, if applicable, award_amend with a dash (“-”) in between.
    "federal_program", -- The number assigned to the federal assistance listing (formerly known as CFDA)
    "federal_award_number", -- The unique identifier of the specific award being reported. Federal Award Identification Number (FAIN) for federal assistance or the Procurement Instrument Identifier (PIID) for procurement.
    "performance_start", -- The date on which effort begins or the award is otherwise effective, or, if applicable, when the emergency declaration began
    "award_amend", -- The Federal identifier for subsequent change or supplement to the initial award, assigned by awarding federal agency.
    "federal_program_title", -- Name of the federal program through which the award was made.
    "fiscal_year", -- The state fiscal year the federal funds were awarded.
    "award_amount", -- The total amount of the initial award or subsequent amendment, or, if applicable, the estimate associated with federal match increase during emergency declaration.
    "award_description", -- A brief description of the purpose of the award.
    "federal_agency" -- The name of the office, administration or service within the federal department responsible for the award.  If not specifically defined, same as the federal department.
FROM
    "mydata-iowa-gov/iowa-pandemic-recovery-reporting-federal-funds-a5qe-4idi:latest"."iowa_pandemic_recovery_reporting_federal_funds"
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/iowa-pandemic-recovery-reporting-federal-funds-a5qe-4idi 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/iowa-pandemic-recovery-reporting-federal-funds-a5qe-4idi: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/iowa-pandemic-recovery-reporting-federal-funds-a5qe-4idi" \
  --handler-options '{
    "domain": "mydata.iowa.gov",
    "tables": {
        "iowa_pandemic_recovery_reporting_federal_funds": "a5qe-4idi"
    }
}'

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/iowa-pandemic-recovery-reporting-federal-funds-a5qe-4idi is just another Postgres schema.