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_payments_to table in this repository, by referencing it like:

"mydata-iowa-gov/iowa-pandemic-recovery-reporting-payments-to-cgm6-jbzf:latest"."iowa_pandemic_recovery_reporting_payments_to"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "amount", -- Amount paid to the organization.
    "vendor_legal", -- Legal name for the organization.
    "federal_department", -- Name of the Federal Department who awarded the federal funds associated with the payment.
    "fund", -- The name of the fund where payment was made.
    "vendor_zip", -- Zip code associated with the physical address of the organization.
    "vendor_city", -- City associated with the physical address of the organization.
    "object_class_name", -- A description of the type of expenditure.
    "federal_agency", -- Name of the Federal Agency responsible for overseeing the Federal funds associated with this payment.
    "budget_fy", -- The four digit budget fiscal year (July 1 - June 30 + holdover) associated with the payment.
    "vendor_id", -- Field is a concatenation of the vendor number and vendor legal name without spaces.
    "vendor_dba", -- Name organization is doing business as.
    "object_class", -- The three digit code used in the state accounting system to designate the type of expenditure.
    "unit_name", -- The name of the organizational unit within the department associated with the payment.
    "state_dept_no", -- The three digit code used to designate the department associated with the payment (e.g., 413).
    "federal_program_title", -- Name of the Federal program that provided the federal funds that supported the payment.
    "payment_issue_date", -- Date payment was made.
    "record_id", -- Journal record number from the State Accounting System, or other unique identifier created for the record.
    "vendor_state", -- State associated with the physical address of the organization.
    "letter_of_credit", -- This is the Letter of Credit value associated with the PPC code in the state accounting system that is unique to the federal award.
    "state_department", -- Name of the State Department making the payment.
    "fund_code", -- The four digit code designating the fund expenses were paid from.
    "unit", -- The four digit code used to designate the organizational unit within the department associated with the payment.
    "vendor_number", -- Unique identifier used in the State Accounting System for the vendor.
    "fiscal_period", -- Two digit fiscal period associated with the payment (i.e., 1-15).
    "geocoded_column", -- Geocoded location is based on the city, state and zip.
    ":@computed_region_g8ff_h7ce",
    ":@computed_region_y683_txed",
    ":@computed_region_hhz5_dst4"
FROM
    "mydata-iowa-gov/iowa-pandemic-recovery-reporting-payments-to-cgm6-jbzf:latest"."iowa_pandemic_recovery_reporting_payments_to"
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-payments-to-cgm6-jbzf 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-payments-to-cgm6-jbzf: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-payments-to-cgm6-jbzf" \
  --handler-options '{
    "domain": "mydata.iowa.gov",
    "tables": {
        "iowa_pandemic_recovery_reporting_payments_to": "cgm6-jbzf"
    }
}'

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-payments-to-cgm6-jbzf is just another Postgres schema.