Query the Data Delivery Network
Query the DDNThe 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 dof_condominium_comparable_rental_income_in_nyc table in this repository, by referencing it like:
"cityofnewyork-us/dof-condominium-comparable-rental-income-in-nyc-9ck6-2jew:latest"."dof_condominium_comparable_rental_income_in_nyc"or in a full query, like:
SELECT
":id", -- Socrata column ID
"expense_per_sqft_1",
"distance_from_condo_in_miles_2",
"net_operating_income_3",
"gross_sqft_3",
"address_3",
"boro_block_lot_3",
"net_operating_income_2",
"estimated_gross_income_2",
"gross_sqft_2",
"year_built_2",
"neighborhood_2",
"boro_block_lot_2",
"market_value_per_sqft_1",
"estimated_expense_1",
"estimated_expense", -- Estimated Expense per SquareFoot * Gross SquareFoot
"total_units_1",
"building_classification_1", -- The Building Class code is used to describe a property’s use. This report includes the two character code as well as the description of the building class.
"neighborhood_1", -- Department of Finance determines the neighborhood name in the course of valuing properties. The common name of the neighborhood is generally the same as the name Finance designates. However, there may be slight differences in neighborhood boundary lines.
"address_1", -- The Street Address of the property
"market_value_per_sqft", -- Full Market Value/ Gross SquareFoot
"full_market_value", -- Current year’s total market value of the land and building
"net_operating_income", -- Estimated Gross Income-Estimated Expense
"expense_per_sqft", -- Estimated expense per squarefoot of median comparable
"total_units", -- Total number of units in the building
"building_classification", -- The Building Class code is used to describe a property’s use. This report includes the two character code as well as the description of the building class.
"address", -- The Street Address of the property
"condo_section", -- The subject condominium is identified using a combination of a condominium number assigned by DoF followed by the condominium suffix. The condominium number is assigned by the Department of Finance for each condominium in New York City. The condominium suffix is a partition of the condominium. A condominium may have multiple residential or commercial suffixes each of which contains individual condominium lots.
"boro_block_lot", -- The Borough-Block-Lot location of the subject condominium. The lot identifies the condominium billing lot generally associated with the condominium management organization.
"market_value_per_sqft_3",
"expense_per_sqft_3",
"estimated_expense_3",
"distance_from_condo_in_miles_1",
"market_value_per_sqft_2",
"full_market_value_2",
"estimated_expense_2",
"address_2",
"distance_from_condo_in_miles",
"full_market_value_1",
"gross_income_per_sqft_1",
"estimated_gross_income_1",
"gross_sqft", -- Gross square footage of the building
"year_built_3",
"neighborhood_3",
"expense_per_sqft_2",
"total_units_2",
"building_classification_2",
"net_operating_income_1",
"year_built_1",
"boro_block_lot_1", -- The Borough-Block-Lot location of the comparable rental property.
"gross_income_per_sqft", -- Estimated income per squarefoot of median comparable
"report_year",
"full_market_value_3",
"total_units_3",
"gross_sqft_1",
"neighborhood", -- Department of Finance determines the neighborhood name in the course of valuing properties. The common name of the neighborhood is generally the same as the name Finance designates. However, there may be slight differences in neighborhood boundary lines.
"estimated_gross_income", -- Estimated Income per SquareFoot * Gross SquareFoot
"gross_income_per_sqft_2",
"gross_income_per_sqft_3",
"building_classification_3",
"estimated_gross_income_3",
"year_built" -- The year the building was built
FROM
"cityofnewyork-us/dof-condominium-comparable-rental-income-in-nyc-9ck6-2jew:latest"."dof_condominium_comparable_rental_income_in_nyc"
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/dof-condominium-comparable-rental-income-in-nyc-9ck6-2jew 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/dof-condominium-comparable-rental-income-in-nyc-9ck6-2jew: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)"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/dof-condominium-comparable-rental-income-in-nyc-9ck6-2jew" \
--handler-options '{
"domain": "data.cityofnewyork.us",
"tables": {
"dof_condominium_comparable_rental_income_in_nyc": "9ck6-2jew"
}
}'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/dof-condominium-comparable-rental-income-in-nyc-9ck6-2jew is just another Postgres schema.