cityofnewyork-us/affordable-housing-production-by-project-hq68-rnsi
Icon for Socrata external plugin

Query the Data Delivery Network

Query the DDN

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 affordable_housing_production_by_project table in this repository, by referencing it like:

"cityofnewyork-us/affordable-housing-production-by-project-hq68-rnsi:latest"."affordable_housing_production_by_project"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "middle_income", -- Middle Income Units are units with rents that are affordable to households earning 121 to 165% of the area median income (AMI).
    "counted_homeownership_units", -- Counted Homeownership Units are the units in the building, counted toward the Housing New York Plan, where assistance has been provided directly to homeowners.
    "extended_affordability_status", -- The Extended Affordability Only field indicates whether the project is considered to be Extended Affordability. An extended affordability project involves no construction, but secures an extended or new regulatory agreement. All extended affordability projects have a ‘reporting construction type’ of ‘preservation.’
    "program_group",
    "senior_units", -- Senior Units are units that are created or preserved for senior households. Senior Units are a subset of the Counted Units in a building, and are also included in the appropriate Extremely Low Income, Low Income, Moderate Income, Middle Income, or Other category.
    "prevailing_wage_status", -- The Prevailing Wage Status field indicates whether the project is subject to prevailing wage requirements, such as Davis Bacon.
    "other", -- Other Units are units reserved for building superintendents.
    "project_id", -- The Project ID is a unique numeric identifier assigned to each project by HPD.
    "project_name", -- The Project Name is the name assigned to the project by HPD.
    "project_start_date", -- The Project Start Date is the date of the project loan or agreement closing.
    "project_completion_date", -- The Project Completion Date is the date that the last building in the project was completed. If the project has not yet completed, then the field is blank.
    "total_units", -- The Total Units field indicates the total number of units, affordable and market rate, in each building.
    "all_counted_units", -- The Counted Units field indicates the total number of affordable units, counted towards the Housing New York plan, that are in the building.
    "counted_rental_units", -- Counted Rental Units are the units in the building, counted toward the Housing New York plan, where assistance has been provided to landlords in exchange for a requirement for affordable units.
    "planned_tax_benefit", -- The Planned Tax Benefit field indicates the type of tax benefit that is anticipated for the project at the time of the project start. Data on actual/final tax benefits received can only be obtained from the NYC Department of Finance. Note: Planned Tax Benefit data for confidential projects are masked.
    "extremely_low_income_units", -- Extremely Low Income Units are units with rents that are affordable to households earning 0 to 30% of the area median income (AMI).
    "very_low_income", -- Very Low Income Units are units with rents that are affordable to households earning 31 to 50% of the area median income (AMI).
    "low_income_units", -- Low Income Units are units with rents that are affordable to households earning 51 to 80% of the area median income (AMI).
    "moderate_income" -- Moderate Income Units are units with rents that are affordable to households earning 81 to 120% of the area median income (AMI).
FROM
    "cityofnewyork-us/affordable-housing-production-by-project-hq68-rnsi:latest"."affordable_housing_production_by_project"
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 cityofnewyork-us/affordable-housing-production-by-project-hq68-rnsi with SQL in under 60 seconds.

This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.cityofnewyork.us. When you querycityofnewyork-us/affordable-housing-production-by-project-hq68-rnsi: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

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

Read the installation docs.

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.cityofnewyork.us, 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 \
  "cityofnewyork-us/affordable-housing-production-by-project-hq68-rnsi" \
  --handler-options '{
    "domain": "data.cityofnewyork.us",
    "tables": {
        "affordable_housing_production_by_project": "hq68-rnsi"
    }
}'

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, cityofnewyork-us/affordable-housing-production-by-project-hq68-rnsi is just another Postgres schema.