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 mined_land_permits_beginning_1974
table in this repository, by referencing it like:
"ny-gov/mined-land-permits-beginning-1974-va8e-9s3h:latest"."mined_land_permits_beginning_1974"
or in a full query, like:
SELECT
":id", -- Socrata column ID
"reclamationtype", -- Type of reclamation: AGRI - Agricultural Cropland; GRAS - Meadow /Grass Land; IND - Industrial; LAKE - Lake /Pond; OPEN - Recreational Open Space; OTH - Other; R/C - Residential / Commercial; WETL - Wetland
"acres_reclaimed", -- Acres Reclaimed represents the number of acres approved as reclaimed at permitted sites since 1975.
"mine_name", -- The name of the mine
"mine_id_number", -- Mine identification code. The first digit is the DEC region number and digits 2-5 are an accession number within the region
":@computed_region_kjdx_g34t",
":@computed_region_wbg7_3whc",
"commodity", -- Mineral resource that has been mined or is planned to be mined; typically a sediment, soil, mineral ore, or rock type
"map_flag", -- Used for symbolizing mines on a map: C - Consolidated Materials Surface Mine; CR - Reclaimed Consolidated Materials Surface Mine; UC - Unconsolidated Materials Surface Mine; UCR - Reclaimed Unconsolidated Materials Surface Mine; UNG - Underground Mine; UNGR - Reclaimed Underground Mine
"initial_permit_date", -- Date of initial permit
"last_modified_date", -- Date record last modified
"permit_issue_date", -- Issue date for current or last permit
":@computed_region_yamh_8v7k",
"permit_end_date", -- Expiration date of current or last permit
"georeference", -- Open Data/Socrata-generated geocoding information based on supplied address components.
"latitude", -- Latitude (decimal degrees) of mine location
"facility_town", -- Town where mine is located
"acres_affected", -- Total amount of acres affected or to be affected from April 1, 1975 to present.
"acresbb_range", -- Range of net affected acres for fee billing purposes. An abbreviated number representation of the amount of net affected acres currently permitted and billed. 1 = a mine with a net affected acreage of up to and including 5 acres, 2 = a mine with a net affected acreage greater than 5 up to and including 10 acres, 3 = a mine with a net affected acreage greater than 10 up to and including 20 acres, 4 = a mine with a net affected acreage greater than 20 up to and including 30 acres, 5 = a mine with a net affected acreage greater than 30 acres.
"permittee_name", -- Name of operator/company holding the mined land reclamation permit
"underground_mine", -- Denotes an underground mine (e.g. accessed by slope, shaft or drift)
"facility_county", -- County where mine is located
"acres_bb", -- The current net affected acres or to be affected acres at the mine site, derived from AcresAffected minus AcresReclaimed and used to determine the billable acres at a mine site.
"date_of_last_inspection", -- Date of last mine inspection
"financial_security_amount", -- Amount of financial security required to ensure reclamation of the site. Financial security funds are held in escrow until such time as an operator has completed mining and reclamation at the site.
"facility_location", -- Name or address of facility location
"acres_life_of_mine", -- The amount of acres that were/are or going to be permitted over the entire life of the mine.
"longitude", -- Longitude (decimal degrees) of mine location
"acres_controlled", -- Total acreage currently controlled by a permittee at any given mine site
"status" -- Mine status codes: A Active; E Expired, not reclaimed; I Inactive, not reclaimed; N Never permitted; P Pending, permit not issued; Q Temporary code for inactive mines, do not bill, not reclaimed; R Reclaimed; T Transfer of permit to another mine; V Never mined; X Exempt from Mined Land Reclamation Law
FROM
"ny-gov/mined-land-permits-beginning-1974-va8e-9s3h:latest"."mined_land_permits_beginning_1974"
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 ny-gov/mined-land-permits-beginning-1974-va8e-9s3h
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; sgr
can 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 clone
and sgr checkout
.
Cloning Data
Because ny-gov/mined-land-permits-beginning-1974-va8e-9s3h: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 ny-gov/mined-land-permits-beginning-1974-va8e-9s3h
Checkout 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 ny-gov/mined-land-permits-beginning-1974-va8e-9s3h:latest
This will download all the objects for the latest
tag of ny-gov/mined-land-permits-beginning-1974-va8e-9s3h
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 ny-gov/mined-land-permits-beginning-1974-va8e-9s3h: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 ny-gov/mined-land-permits-beginning-1974-va8e-9s3h:latest
This 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, ny-gov/mined-land-permits-beginning-1974-va8e-9s3h
is just another Postgres schema.