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 spill_incidents_from_january_1_1996_to_june_30 table in this repository, by referencing it like:
"ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg:latest"."spill_incidents_from_january_1_1996_to_june_30"or in a full query, like:
SELECT
":id", -- Socrata column ID
"releasetype", -- The categories of the reported substance(s) released: petroleum, chemical, dialect, hazardous waste, sewage related, biomedical, gas emission, other, or not specified.
"location", -- Any known address or geographic information associated with the location of the incident as it was reported. -- this may or may not be the originating location of the release
"mediainfo", -- The environmental media or setting affected by the release
"causeinfo", -- Cause of incident, if known
"actions", -- Response actions taken to address the release, if known at the time of the incident’s report to CT DEEP
"waterbodiesaffected", -- Waterbody name(s) if known or expected to be affected
"waterbody", -- If known, the type of waterbody affected, such as a lake, stream, catch basins
"emergencymeasures", -- Additional information regarding the incident
"quanlbs", -- Amount in Pounds of substance spilled or found -- “0” indicates indicates zero or can indicate an unknown amount. Note that the quantity can include the volume of contaminated soil or water combined with the spilled substance. Standard data qualifiers are symbols for greater than (>), less than (<), and approximate (~), though other symbols may be present, either intentionally or as typographic errors.
"quandrums", -- Amount in Drums of substance spilled or found --“0” indicates indicates zero or can indicate an unknown amount. Note that the quantity can include the volume of contaminated soil or water combined with the spilled substance. Standard data qualifiers are symbols for greater than (>), less than (<), and approximate (~), though other symbols may be present, either intentionally or as typographic errors.
"quanfeet", -- Amount in Cubic Feet of substance spilled or found -- “0” indicates indicates zero or can indicate an unknown amount. Note that the quantity can include the volume of contaminated soil or water combined with the spilled substance. Standard data qualifiers are symbols for greater than (>), less than (<), and approximate (~), though other symbols may be present, either intentionally or as typographic errors.
"quanyards", -- Amount in Cubic Yards of substance spilled or found -- “0” indicates indicates zero or can indicate an unknown amount. Note that the quantity can include the volume of contaminated soil or water combined with the spilled substance. Standard data qualifiers are symbols for greater than (>), less than (<), and approximate (~), though other symbols may be present, either intentionally or as typographic errors.
"quangallons", -- Amount in Gallons of substance spilled or found -- “0” indicates indicates zero or can indicate an unknown amount. Note that the quantity can include the volume of contaminated soil or water combined with the spilled substance. Standard data qualifiers are symbols for greater than (>), less than (<), and approximate (~), though other symbols may be present, either intentionally or as typographic errors.
"releasesubstance", -- Common name or category of spilled substance or material
"responsibility", -- If known at the time of the incident report, the name of the person or entity who accepts responsibility for the release.
"repzip", -- The postal zip code associated with the address of the person or entity identified as causing the spill incident.
"repstate", -- The state associated with the address of the person or entity identified as causing the spill incident
"reptown", -- The town associated with the address of the person or entity identified as causing the spill incident
"repstreet", -- The address of the individual or entity identified as causing the spill incident
"discharger", -- The person or entity identified as causing the spill incident
"representing", -- The entity reporting the spill incident
"reportedby", -- The person or entity reporting the spill incident
"status", -- The administrative status of the agency’s report, with “closed” indicating either that a report has been issued if a response occurred, or that no emergency response occurred.
"stateofrelease", -- The state is generally Connecticut, though reports of spills in neighboring states may be reported if occurring near Connecticut, particularly in water bodies near state borders
"townrelease", -- The town in which the release occurred -- the name is the official Connecticut town name, not the village or borough name
"releasedatetime", -- The date and time the spill incident occurred (sometimes estimated)
"date_reported_time_reported", -- The date and time the spill incident information was received
"assignedto", -- The Emergency Response Coordinator or Supervisor initially assigned to respond to the incident
"caseno", -- The unique administrative case filing number -- the first two to four digits represent the year in which the incident was reported
"year" -- The year the incident was reported
FROM
"ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg:latest"."spill_incidents_from_january_1_1996_to_june_30"
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 ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg 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 ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg: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 ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsgCheckout 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 ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg:latestThis will download all the objects for the latest tag of ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg 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 ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg: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 ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg: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, ct-gov/spill-incidents-from-january-1-1996-to-june-30-wr2a-rnsg is just another Postgres schema.