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 dwr_well_geophysical_log table in this repository, by referencing it like:
"colorado-gov/dwr-well-geophysical-log-cfyk-gwjj:latest"."dwr_well_geophysical_log"or in a full query, like:
SELECT
":id", -- Socrata column ID
"longitude", -- Longitude (decimal degrees)
"range", -- Legal location - range
"township", -- Legal location - Township number and direction
"management_district", -- Thirteen local districts, within the Designated Basins, with additional administrative authority
"wd", -- DWR Water District
"locnum", -- Bureau of Reclamation location identification string based on the PLSS location
"base_of_grout", -- Depth from surface to base of grout (feet)
"bottom_perforated_casing", -- Depth from surface to bottom of perforated casing (feet)
"log_date", -- Date that geophysical log was recorded
"utm_x", -- The x (Easting) component of the Universal Transverse Mercator system. (Zone 12, NAD83 datum)
"designated_basin", -- Designated basin where well is located
"wdid", -- DWR unique structure identifier
"top_perforated_casing", -- Depth from surface to top of perforated casing (feet)
"log_bottom", -- Bottom depth of performed geophysical log (feet)
"log_type", -- Type of geophysical logging performed
"location_city",
"location", -- Latitude/Longitude where the Well is located
"section", -- Legal location - section number
"aquifer_picks", -- Aquifers identified from geophysical log
"elevation_accuracy", -- Accuracy of the ground surface elevation
"elevation", -- Surface elevation at the location of the well (feet above mean sea level)
"location_accuracy", -- Accuracy of location coordinates
"latitude", -- Latitude (decimal degrees)
"utm_y", -- The y (Northing) component of the Universal Transverse Mercator system. (Zone 12, NAD83 datum)
"q160", -- Legal location - 160 acre quarter section
"well_depth", -- Completed depth of well (ft)
"pm", -- Principal Meridian
"location_address",
"coordsew", -- Distance from East/West section line (feet)
"div", -- DWR Water Division
"location_state",
"coordsns", -- Distance from North/South section line (feet)
"county", -- County where the well is located
"cogcc_api", -- Colorado Oil and Gas Conservation Commission well identifier
"permit", -- Concatenation of permit number, suffix code, and replacement code
"well_name", -- Name of well in DWR database
"location_zip",
"q10", -- Legal location - 10 acre quarter section
"receipt", -- Permit application receipt number
"modified", -- Last date and time this record was modified in the DWR database
"q40", -- Legal location - 40 acre quarter section
":@computed_region_nku6_53ud",
"more_information", -- Hyperlink to additional details
"coordsew_dir", -- Direction of measurement from East/West section line
"log_top", -- Depth to depth of performed geophysical log (feet)
"coordsns_dir" -- Direction of measurement from North/South section line
FROM
"colorado-gov/dwr-well-geophysical-log-cfyk-gwjj:latest"."dwr_well_geophysical_log"
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 colorado-gov/dwr-well-geophysical-log-cfyk-gwjj 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 colorado-gov/dwr-well-geophysical-log-cfyk-gwjj: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 colorado-gov/dwr-well-geophysical-log-cfyk-gwjjCheckout 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 colorado-gov/dwr-well-geophysical-log-cfyk-gwjj:latestThis will download all the objects for the latest tag of colorado-gov/dwr-well-geophysical-log-cfyk-gwjj 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 colorado-gov/dwr-well-geophysical-log-cfyk-gwjj: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 colorado-gov/dwr-well-geophysical-log-cfyk-gwjj: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, colorado-gov/dwr-well-geophysical-log-cfyk-gwjj is just another Postgres schema.