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 cityparish_employee_annual_salaries table in this repository, by referencing it like:
"brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw:latest"."cityparish_employee_annual_salaries"or in a full query, like:
SELECT
":id", -- Socrata column ID
"emplee_reimburst", -- Any employee reimbursements received throughout the year
"state_2_pct", -- Statute requiring Fire employees to receive a raise of at least 2% each year after completion of 3 years of continuous service in the Fire Department. Effective for 20 years or until the employee's 23rd year of service.
"prison_assgn", -- Employees assigned to work at the Parish Prison
"haz_pay", -- Hazardous pay for sworn police employees, or Entomologist performing aerial spraying
"longevity", -- Percentage pay based on years of service
"commdr_pay", -- Job assignments designated by the Police Chief
"uniqueid", -- Sworn police employees assigned as Police Pilots
"workers_comp", -- Workers compensation
"first_name",
"police_suit_allowance", -- Police suit allowance for detectives
"aviat_pay", -- Sworn police employees assigned as Police Pilots
"employment_status", -- Employee's status with the City-Parish. A=Active; I=Inactive
"base_pay", -- Annual salary of employee, not including any additional earning allowances
"tot_ot_hours", -- Total number of overtime hours worked. 2018 OT hours were not captured when we migrated to the new payroll system. Moving forward this data will be available.
"sevpay", -- Severance pay
"employee_refund", -- Refunds paid to employee
"field_train_pay", -- Municipal police employees performing training duties
"department_name",
"last_name",
"pay_location_code",
"pay_location_desc", -- Corresponds to the division or location where the employee works
"job_code",
"special_assign", -- Special assignment pay
"employment_end_date", -- End of service date, the employee may have retired, resigned or was terminated
"department_num",
"year",
"middle_init",
"meal_allowance", -- Meal allowance for EMS employees
"job_title",
"current_hire_date", -- Most current date employee hired (Does not include broken service with the City-Parish)
"gross_pay", -- Base pay plus overtime pay plus any extra earnings
"tot_ot", -- Overtime pay
"shift_diff_pay", -- Shift differential pay
"pay_adjustments", -- Any pay adjustments received throughout the year
"car_allowance", -- Car allowance
"state_supplemental_jp", -- State supplemental pay for Justice of the Peace
"education_pay", -- Educational pay for employees receiving State Supplemental Pay, or for Municipal Fire and Police employees
"trans_comp_pay", -- A 56 hour fire employee who reports to duty and is transferred to another fire station
"engineer_license" -- Post license experience allowance for licensed professional engineers
FROM
"brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw:latest"."cityparish_employee_annual_salaries"
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 brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw 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 brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw: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 brla-gov/cityparish-employee-annual-salaries-g9vh-zeiwCheckout 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 brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw:latestThis will download all the objects for the latest tag of brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw 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 brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw: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 brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw: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, brla-gov/cityparish-employee-annual-salaries-g9vh-zeiw is just another Postgres schema.