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 oregon_prod_invest_fund_opif_auction_results
table in this repository, by referencing it like:
"oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu:latest"."oregon_prod_invest_fund_opif_auction_results"
or in a full query, like:
SELECT
":id", -- Socrata column ID
"credit_amt", -- Actual tax credit certificate amount issued to business or individual purchaser
"amt_paid", -- Actual amount paid by business or individual purchaser
"zip_code", -- Postal code (zip) of business or individual
"state", -- State location for business or individual
"city", -- City location for business or individual
"address", -- Physical street address of business or individual
"first_name", -- First name of individual (if an individual was the purchaser)
"business_name", -- Name of business (if a business was the purchaser)
"fiscal_year", -- The year associated with this report, running from July 1, 20xx of one year, to June 30, 20yy of the following year.
"outcomes", -- Outcome of purchase and tax credit issue process
"last_name", -- Last name of individual (if an individual was the purchaser)
"taxpayer_requirement" -- Requirements of purchaser to receive tax credits
FROM
"oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu:latest"."oregon_prod_invest_fund_opif_auction_results"
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 oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu
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 oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu: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 oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu
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 oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu:latest
This will download all the objects for the latest
tag of oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu
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 oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu: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 oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu: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, oregon-gov/oregon-prod-invest-fund-opif-auction-results-kijp-9nsu
is just another Postgres schema.