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 yourmoney_active_pension_members table in this repository, by referencing it like:
"nj-gov/yourmoney-active-pension-members-44xg-bswk:latest"."yourmoney_active_pension_members"or in a full query, like:
SELECT
":id", -- Socrata column ID
"all_employers_salary_amt", -- The total salary eligible for pension credit reported by all employers for all locations during the most recent four quarters.
"current_employer_salary_amt", -- The salary eligible for pension credit reported by the current employer for the current location during the most recent four quarters.
"service_months_qty", -- The months of service in the pension fund for the most recent partial year credited to the member.
"service_years_qty", -- The full years of service in the pension fund credited to the member.
"pension_group_name", -- The name of the pension subgroup if applicable, or NOT APPLICABLE.
"location_name", -- The county in which the employer reporting at the end of the reporting period is located, or REGIONAL, or STATEWIDE.
"location_code", -- The code that identifies the location of the employer reporting at the end of the reporting period.
"member_first_name", -- The first name of the member at the end of the reporting period.
"member_last_name", -- The last name of the member at the end of the reporting period.
"_20_year_status", -- The status that indicates whether the member is exempt from Chapter 78. “YES” indicates the member attained 20 years of service before the Chapter 78 effective date (June 28, 2012) and is exempt from allowance-based health benefit premium calculations if the member retires with at least 25 years of service. All other members are “NO”.
"_25_year_date", -- The date upon which a member achieved twenty-five years of pension service, otherwise blank.
"total_months_qty", -- The total months of service in the pension fund credited to the member (where each full year of service equals twelve months).
"veteran_status", -- The veteran status of the member for pension purposes.
"employer_name", -- The name of the employer reporting at the end of the reporting period.
"enrollment_date", -- The date that the member enrolled in the pension fund.
"membership_tier", -- The category of retirement benefits available based on the pension fund enrollment date of the member.
"pension_group_id", -- The identifier of the pension subgroup if applicable, or N.
"member_mi", -- The middle initial of the member at the end of the reporting period.
"pension_fund_name", -- The name of the pension fund for which this data is being reported.
"pension_fund_id", -- The identifier of the pension fund for which this data is being reported.
"as_of_date" -- The last day of the four quarters of data represented in this dataset.
FROM
"nj-gov/yourmoney-active-pension-members-44xg-bswk:latest"."yourmoney_active_pension_members"
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 nj-gov/yourmoney-active-pension-members-44xg-bswk 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 nj-gov/yourmoney-active-pension-members-44xg-bswk: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 nj-gov/yourmoney-active-pension-members-44xg-bswkCheckout 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 nj-gov/yourmoney-active-pension-members-44xg-bswk:latestThis will download all the objects for the latest tag of nj-gov/yourmoney-active-pension-members-44xg-bswk 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 nj-gov/yourmoney-active-pension-members-44xg-bswk: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 nj-gov/yourmoney-active-pension-members-44xg-bswk: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, nj-gov/yourmoney-active-pension-members-44xg-bswk is just another Postgres schema.