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 financial_empowerment_centers table in this repository, by referencing it like:
"cityofnewyork-us/financial-empowerment-centers-dt2z-amuf:latest"."financial_empowerment_centers"or in a full query, like:
SELECT
":id", -- Socrata column ID
"council_district", -- Community Board number which represents the Community District or joint interest area where the Financial Empowerment Center is located.
"location_address",
"location_zip",
"telephone", -- Phone number for booking an appointment at a Financial Empowerment Center.
"city", -- USPS preferred city name for the address where the Financial Empowerment Center is located.
"provider", -- Financial counseling service provider that operates the Financial Empowerment Center.
"language_s", -- Language spoken by financial counselors at the Financial Empowerment Center.
"street", -- The street name where the Financial Empowerment Center is located.
"zip_code", -- ZIP code where the Financial Empowerment Center is located.
"borough", -- The name of the NYC Borough where the Financial Empowerment Center is located.
"location_state",
":@computed_region_f5dn_yrer",
"building", -- The building number for the address where the Financial Empowerment Center is located. Note, some building numbers in Queens may include a dash character as part of the number.
"days_open", -- Weekdays when the Financial Empowerment Center financial counseling services are regularly provided.
"hours", -- Financial Empowerment Center typical hours of operation.
"site_location_address", -- The Financial Empowerment Center address with unit information.
"community_board", -- Council District number where Financial Empowerment Center is located.
"bbl", -- A concatenation of the borough, block, and lot numbers where Financial Empowerment Center is located. Identifies a parcel of real property in New York City.
"host_organization", -- The organization that hosts the Financial Empowerment Center.
"nta", -- Neighborhood Tabulation Area (NTA) where Financial Empowerment Center is located.
"x_coordinates", -- The X Coordinate of the XY coordinate pair where the Financial Empowerment Center is located. NAD 1983 StatePlane New York Long Island FIPS 3104, Unit of measure: Feet
"bin", -- Building Identification Number (BIN) for the building in which the Financial Empowerment Center is located. The BIN is a seven-digit numerical identifier unique to each building in the City of New York. The first digit is the Borough Code. If the borough code is followed by all zeroes (commonly referred to as a ‘million BIN’, this indicates that a BIN has not been assigned.
"location", -- Concatenated Latitude and Longitude coordinate location where Financial Empowerment Center is located. In unit of decimal degree
"census_tract", -- The 2010 US Census Tract where the Financial Empowerment Center is located.
"longitude", -- Longitude of the Financial Empowerment Center location.
"latitude", -- Latitude of the Financial Empowerment Center location.
"y_coordinates", -- The Y Coordinate of the XY coordinate pair where the Financial Empowerment Center is located. NAD 1983 StatePlane New York Long Island FIPS 3104, Unit of measure: Feet
"location_city",
":@computed_region_efsh_h5xi",
":@computed_region_yeji_bk3q",
":@computed_region_92fq_4b7q",
":@computed_region_sbqj_enih"
FROM
"cityofnewyork-us/financial-empowerment-centers-dt2z-amuf:latest"."financial_empowerment_centers"
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/financial-empowerment-centers-dt2z-amuf 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/financial-empowerment-centers-dt2z-amuf: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/financial-empowerment-centers-dt2z-amuf" \
--handler-options '{
"domain": "data.cityofnewyork.us",
"tables": {
"financial_empowerment_centers": "dt2z-amuf"
}
}'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/financial-empowerment-centers-dt2z-amuf is just another Postgres schema.