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_authority_payroll table in this repository, by referencing it like:
"nj-gov/yourmoney-authority-payroll-kiki-imre:latest"."yourmoney_authority_payroll"or in a full query, like:
SELECT
":id", -- Socrata column ID
"athrty_name", -- An independent authority or commission that is neither a cabinet department nor an agency in but not of a cabinet department.
"as_of_date", -- The last day of the quarter of data represented in this dataset.
"uniqueid", -- A unique identifier using the employee name, authority name, and job title.
"ytd_earnings", -- Sum of all payments for the employee during the reporting period.
"all_other_payments", -- Wages earned by an employee not considered regular pay or overtime payments.
"full_name", -- Full name of the employee at the end of the reporting period.
"overtime_payments", -- Overtime wages.
"regular_pay", -- Wages earned by an employee for working a predetermined number of hours or days in a week as dictated by the employee’s title.
"calendar_quarter", -- Payroll data will be published quarterly. The single digit calendar quarter represents the end of the period that the data spans and not the actual quarter that the payment was made. For example, when calendar quarter is set to ‘2’, the data would include payments made from January through June for the given calendar year. Calendar year and calendar quarter together represent the end of the reporting period.
"compensation_method", -- Identifies the basis by which an employee’s regular pay will be calculated. This is the compensation method associated with the employee at the end of the reporting period.
"employee_relations_group", -- Classification indicating whether employee is aligned or not aligned with a union and what type of work that unit performs. This grouping determines what salary and benefits the employee receives. This is the employee relations group associated with the employee at the end of the reporting period.
"calendar_year", -- Four digit year representing the twelve month period starting with January and ending with December. Indicates the calendar year in which payments were actually made to the employee. Calendar year and calendar quarter together represent the end of the reporting period.
"master_title_desc", -- The title is a descriptive name that identifies a position or group of positions with similar duties, responsibilities and qualifications. This is the title associated with the employee at the end of the reporting period.
"master_section_desc", -- The area of the department to which the employee is assigned at the end of the reporting period.
"salary_hourly_rate" -- Depending on the value in the column Compensation Method, the value in this column is either the annual salary, hourly rate or a daily rate for the employee at the end of the reporting period. When the compensation method is ‘Part Time’ the salary listed has been adjusted to represent the part time percentage.
FROM
"nj-gov/yourmoney-authority-payroll-kiki-imre:latest"."yourmoney_authority_payroll"
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-authority-payroll-kiki-imre 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-authority-payroll-kiki-imre: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-authority-payroll-kiki-imreCheckout 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-authority-payroll-kiki-imre:latestThis will download all the objects for the latest tag of nj-gov/yourmoney-authority-payroll-kiki-imre 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-authority-payroll-kiki-imre: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-authority-payroll-kiki-imre: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-authority-payroll-kiki-imre is just another Postgres schema.