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 facilities_database table in this repository, by referencing it like:
"cityofnewyork-us/facilities-database-ji82-xba5:latest"."facilities_database"or in a full query, like:
SELECT
":id", -- Socrata column ID
"ycoord", -- The Y coordinate of the location either calculated using the coordinates in the source data or provided by GeoClient.
"optype", -- Indicates whether the operating entity is public or non-public.
"opabbrev", -- Abbreviation for the oversight agency.
"overagency", -- The name of the agency overseeing the facility.
"opname", -- The name of the operating entity.
"overlevel", -- The level of government of the oversight agency: City, State, City-State, Federal, or Non-public Oversight.
"boro", -- The full name the borough the facility is within.
"zipcode", -- The ZIP Code the facility is within. This eld contains some blanks for facilities that do not overlap with the shoreline Zip Code boundaries.
"latitude", -- The latitude of the location either calculated using the coordinates in the source data or provided by GeoClient.
"longitude", -- The longitude of the location either calculated using the coordinates in the source data or provided by GeoClient.
"xcoord", -- The X coordinate of the location either calculated using the coordinates in the source data or provided by GeoClient.
"bbl", -- The BBL values for the tax lots the facility is located on. This eld contains blanks, because some facility categories, like pedestrian plazas are not located on tax lots.
"commboard", -- The Community District the facility is within. This eld contains blanks because the Community District boundaries do not capture facilities beyond the shoreline.
"council", -- The City Council District the facility is within
"overabbrev", -- Abbreviation for the oversight agency.
"policeprct",
"facdomain", -- The value representing the facility domain, the broadest category.
"schooldist",
"censtract", -- The U.S. Census Tract the facility is within
"nta", -- The Neighborhood Tabulation Area (NTA) the facility is within. This eld contains blanks because the NTA boundaries do not capture facilities beyond the shoreline.
"facgroup", -- The value representing the group type, the second broadest category.
"facsubgrp", -- The value representing the subgroup type.
"capacity", -- How many of capacity type/unit the facility is intended to hold. For many types of facilities, no capacity information was available. The capacity-related elds are blank when no information was provided in the source data.
"factype", -- The value representing the facility type, the most granular category of facilities.
"datasource", -- The Agency whose data was used as the source for the record.
"captype", -- The value representing the unit type of capacity, such as beds, visitors, seats, etc.
"borocode", -- The number value representing the borough the facility is within.
"bin", -- The BIN values for the buildings the facility is located in. This eld contains blanks, because 1) some lots do not have buildings on them, and 2) some lots have multiple buildings and a single BIN could not be reliably assigned given the information provided in the source data.
"uid", -- Universal Unique Identifier. When a row is added to the table the UID is automatically generated, enabling database replication.
"servarea",
"facname", -- The name of the facility in proper case.
"addressnum", -- The address number of where the facility is located, validated by GeoClient. If the address that is available for the site is not complete with an address number (only the street name), this eld is left blank.
"streetname", -- The name of the street where the facility is located, validated by GeoClient. If the address that is available for the site is not complete with an address number (only the street name), this eld is left blank.
"address", -- The concatenated value of AddressNumber and StreetName of where the facility is located. If there is not a valid, complete address available, any location description that was provided is included in this field.
"city" -- The USPS preferred name of the addressed city where the facility is located. Generated by GeoClient and spatial joins. This eld contains some blanks for facilities that do not overlap with the shoreline Zip Code boundaries.
FROM
"cityofnewyork-us/facilities-database-ji82-xba5:latest"."facilities_database"
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/facilities-database-ji82-xba5 with SQL in under 60 seconds.
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, 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 (like this repository), where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.
Cloning Data
Because cityofnewyork-us/facilities-database-ji82-xba5:latest is a Splitgraph Image, you can clone the data from Spltgraph Cloud to your local engine, where you can query it like any other Postgres database, using any of your existing tools.
First, install Splitgraph if you haven't already.
Clone the metadata with sgr clone
This will be quick, and does not download the actual data.
sgr clone cityofnewyork-us/facilities-database-ji82-xba5Checkout the data
Once you've cloned the data, you need to "checkout" the tag that you want. For example, to checkout the latest tag:
sgr checkout cityofnewyork-us/facilities-database-ji82-xba5:latestThis will download all the objects for the latest tag of cityofnewyork-us/facilities-database-ji82-xba5 and load them into the Splitgraph Engine. Depending on your connection speed and the size of the data, you will need to wait for the checkout to complete. Once it's complete, you will be able to query the data like you would any other Postgres database.
Alternatively, use "layered checkout" to avoid downloading all the data
The data in cityofnewyork-us/facilities-database-ji82-xba5:latest is 0 bytes. If this is too big to download all at once, or perhaps you only need to query a subset of it, you can use a layered checkout.:
sgr checkout --layered cityofnewyork-us/facilities-database-ji82-xba5:latestThis will not download all the data, but it will create a schema comprised of foreign tables, that you can query as you would any other data. Splitgraph will lazily download the required objects as you query the data. In some cases, this might be faster or more efficient than a regular checkout.
Read the layered querying documentation to learn about when and why you might want to use layered queries.
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/facilities-database-ji82-xba5 is just another Postgres schema.