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 permanent_perm_and_labor_condition_application_h1b table in this repository, by referencing it like:
"cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb:latest"."permanent_perm_and_labor_condition_application_h1b"or in a full query, like:
SELECT
":id", -- Socrata column ID
"pw_unit_of_pay", -- Unit of pay for prevailing wage.
"naics_industry_group", -- Industry group, as classified by the first four digits of the NAICS code.
"naics_subsector", -- Industry subsector, as classified by the first three digits of the NAICS code.
"soc_code", -- Occupational code associated with the job title as classified by the Bureau of Labor Statistics via the Standard Occupational Classification system.
"status", -- Indicates whether application was certified, withdrawn or denied. For certified application applications, indicates whether the application was later withdrawn or expired.
"naics_sector", -- Industry sector, as classified by the first two digits of the NAICS code.
"naics_code", -- Industry code associated with the employer requesting permanent labor condition, as classified by the North American Industrial Classification System (NAICS).
"visa_program", -- Visa program through which the application was received (LCA for Labor Condition Application programs (H-1B, H-1B1, E-3), PERM for Permanent Employment Certification program).
"soc_name", -- Detailed occupation as classified by the Bureau of Labor Statistics via the Standard Occupational Classification system.
"soc_broad_group", -- Broad occupation group, as designated by the SOC system.
"soc_minor_group", -- Minor occupation group as classified by the Bureau of Labor Statistics via the Standard Occupational Classification system.
"soc_major_group", -- Major occupation group as classified by the Bureau of Labor Statistics via the Standard Occupational Classification system.
"total_workers_lca", -- The number of employees that may be hired using one LCA. PERM applications are always submitted on behalf of a single potential employee.
"fy", -- Federal fiscal year during which the application was submitted.
"prevailing_wage" -- Prevailing wage for the job being requested.
FROM
"cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb:latest"."permanent_perm_and_labor_condition_application_h1b"
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 cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb 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 cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb: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 cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphbCheckout 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 cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb:latestThis will download all the objects for the latest tag of cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb 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 cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb: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 cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb: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, cambridgema-gov/permanent-perm-and-labor-condition-application-h1b-fmbp-nphb is just another Postgres schema.