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 inmate_medicationassisted_treatment_mat_quarter_1 table in this repository, by referencing it like:

"pa-gov/inmate-medicationassisted-treatment-mat-quarter-1-m8cr-cygf:latest"."inmate_medicationassisted_treatment_mat_quarter_1"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "total_admissions", -- Inmates whom have been prescribed any drug. In any given year. An inmate who has been prescribed multiple different drugs will have multiple admissions. Or an inmate who has been prescribed the same drug in different years would be admitted for as many years as they are in the program. This factually means there are fewer new admissions at the beginning of any given year due to roll over.
    "time_period_dates", -- Based on the Time Period Column, the date is represented by the Q’s or quarters Q1-Q4 = January-December or Q1=January to March, Q2=April to June, Q3=July to September, and Q4=October to December of any given year.
    "age", -- The Inmate age based on the day the data is collected. Ranges include: All or age 0 to 99, 0-11years old, 12-19yo, 20-24yo, 25-29yo, 30-34yo, 35-39yo, 40-44yo, 45-49yo, 50-55yo, and 56-99yo. During collection age is not static. Example: If data is collected on 1/2/18 and if an inmate is admitted for Revia on 1/1/18 and his birthday is 1/2/86 the age will reflect his actual birth date.
    "time_period", -- Based on two values either each Quarter 3 months: (Q1=January to March, Q2=April to June, Q3=July to September, and Q4=October to December) or Combined Quarters Q1-Q4=January-December of the year described.
    "drug_type", -- This is based on what drug the inmate has taken when admitted into the program. An Inmate can have multiple drug admissions. Example: An inmate who takes Revia for 3 days then switches to Vivitrol will be admitted twice. Or if an inmate switches from Suboxone to Revia then to Vivitrol they would be admitted 3 times.
    "ethnicity", -- Based on 4 categories: Caucasian, African American/Black,Asian, Other/Declined. It is worth noting no Hispanic ethic group was recognized. 
    "gender", -- Based on Male, Female or All only. 
    "year", -- Actual year of admission. An Inmate whom is prescribed a medication that is daily who rolls over to a new calendar year would be admitted twice. 
    "geographic_name", -- Commonwealth representing all areas of Pennsylvania.
    "geographic_area" -- Statewide for Pennsylvania.
FROM
    "pa-gov/inmate-medicationassisted-treatment-mat-quarter-1-m8cr-cygf:latest"."inmate_medicationassisted_treatment_mat_quarter_1"
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 pa-gov/inmate-medicationassisted-treatment-mat-quarter-1-m8cr-cygf with SQL in under 60 seconds.

This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.pa.gov. When you querypa-gov/inmate-medicationassisted-treatment-mat-quarter-1-m8cr-cygf: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.pa.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 \
  "pa-gov/inmate-medicationassisted-treatment-mat-quarter-1-m8cr-cygf" \
  --handler-options '{
    "domain": "data.pa.gov",
    "tables": {
        "inmate_medicationassisted_treatment_mat_quarter_1": "m8cr-cygf"
    }
}'

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, pa-gov/inmate-medicationassisted-treatment-mat-quarter-1-m8cr-cygf is just another Postgres schema.