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 employment_status_of_the_civilian_noninstitutional table in this repository, by referencing it like:

"ny-gov/employment-status-of-the-civilian-noninstitutional-wkup-gbbg:latest"."employment_status_of_the_civilian_noninstitutional"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "demographics", -- Characteristics of population
    "civilian_labor_force", -- All persons in the civilian noninstitutional population who are either employed or unemployed.
    "not_in_labor_force", -- The labor force is made up of the employed and the unemployed. The remainder—those who have no job and are not looking for one—are counted as not in the labor force. Many who are not in the labor force are going to school or are retired. Family responsibilities keep others out of the labor force. Also included in "not in labor force" are discouraged workers who were not currently looking for work specifically because they believed no jobs were available for them or there were none for which they would qualify.
    "unemployed_as_a_percent_of_civilian_labor_force", -- The number unemployed as a percent of the civilian labor force.
    "unemployed", -- People are classified as unemployed if they do not have a job, have actively looked for work in the prior 4 weeks, and are currently available for work.
    "year", -- Survey Year
    "employed", -- People are considered employed if they did any work at all for pay or profit during the survey reference week. This includes all parttime and temporary work, as well as regular full-time, year-round employment. Individuals also are counted as employed if they have a job at which they did not work during the survey week, whether they were paid or not, because they were: on vacation, ill, experiencing child care problems, on maternity or paternity leave, taking care of some other family or personal obligation, involved in a labor dispute or prevented from working by bad weather.
    "employed_as_a_percent_of_population", -- The number employed as a percent of the civilian noninstitutional population.
    "civilian_labor_force_as_a_percent_of_population", -- The civilian labor force as a percent of the civilian noninstitutional population.
    "civilian_noninstitutional_population", -- People 16 years of age and older residing in New York State who are not inmates of institutions, and who are not on active duty in the Armed Forces.
    "demographic_description" -- Characteristic groupings
FROM
    "ny-gov/employment-status-of-the-civilian-noninstitutional-wkup-gbbg:latest"."employment_status_of_the_civilian_noninstitutional"
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/employment-status-of-the-civilian-noninstitutional-wkup-gbbg with SQL in under 60 seconds.

This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.ny.gov. When you queryny-gov/employment-status-of-the-civilian-noninstitutional-wkup-gbbg: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 data.ny.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 \
  "ny-gov/employment-status-of-the-civilian-noninstitutional-wkup-gbbg" \
  --handler-options '{
    "domain": "data.ny.gov",
    "tables": {
        "employment_status_of_the_civilian_noninstitutional": "wkup-gbbg"
    }
}'

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, ny-gov/employment-status-of-the-civilian-noninstitutional-wkup-gbbg is just another Postgres schema.