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 governors_executive_budget_program_measures_sfy table in this repository, by referencing it like:
"pa-gov/governors-executive-budget-program-measures-sfy-tdq9-ue62:latest"."governors_executive_budget_program_measures_sfy"or in a full query, like:
SELECT
":id", -- Socrata column ID
"attendance_at_public_library", -- Total number of people who attended public library programs either in person or virtually.
"students_in_state_funded", -- Total number of funded seats in Head Start Supplemental programs.
"fiscal_year", -- Fiscal year for which the program measure values in this row are applicable. Fiscal Years 2021-22 and 2022-23 are estimated amounts based on agency projections.
"percentage_of_full_time_first", -- Percentage of full-time, first-time students at state system and state-related universities who earn a degree within 150 percent of normal time, or six years.
"percentage_of_students_3", -- Percentage of students enrolled in public or private colleges both in Pennsylvania and out-of-state within 16 months of graduating from a Pennsylvania public high school.
"number_of_items_accessed", -- Total number of items accessed from the State Library, including books, journals, research items, etc.
"percentage_of_students_2", -- Percentage of all students, enrolled for a full academic year, scoring Proficient or Advanced on the Pennsylvania System of School Assessment (PSSA) in grades 3 through 8 for Science.
"percentage_of_students_1", -- Percentage of all students, enrolled for a full academic year, scoring Proficient or Advanced on the Pennsylvania System of School Assessment (PSSA) in grades 3 through 8 for English Language Arts.
"number_of_students_enrolled", -- Total number of students enrolled in PDE-approved career and technical education (CTE) programs.
"students_in_pa_pre_k_counts", -- Total number of funded seats in the Pre-K Counts program.
"percentage_of_pennsylvania", -- Percentage of Pennsylvania high school graduates who earn a degree from public or private colleges both in Pennsylvania and out-of-state within six years of high school graduation.
"use_of_power_library_online", -- Total number of POWER Library subscription database items viewed.
"percentage_of_pennsylvania_1", -- Percentage of Pennsylvania residents who have a postsecondary degree or industry credential.
"number_of_recorded_or_braille", -- Total number of items borrowed or downloaded through the Library of Accessible Media for Pennsylvanians (LAMP).
"percentage_of_students", -- Percentage of all students, enrolled for a full academic year, scoring Proficient or Advanced on the Pennsylvania System of School Assessment (PSSA) in grades 3 through 8 for Mathematics.
"percentage_of_full_time_first_1", -- Percentage of full-time, first-time students at community colleges who earn a degree within 150 percent of normal time, or three years.
"number_of_internet_sessions", -- Total number of times that individuals access the internet through public computers and wireless devices at library locations.
"budget_book_budget_year", -- This is the State Fiscal Year when the program measure numbers in this row were submitted for the Governor's Executive Budget Book.
"number_of_children" -- Total number of students participating in Early Intervention programs.
FROM
"pa-gov/governors-executive-budget-program-measures-sfy-tdq9-ue62:latest"."governors_executive_budget_program_measures_sfy"
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 pa-gov/governors-executive-budget-program-measures-sfy-tdq9-ue62 with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.pa.gov. When you querypa-gov/governors-executive-budget-program-measures-sfy-tdq9-ue62:latest on the DDN, we "mount" the repository using the socrata mount handler. The mount handler proxies your SQL query to the upstream data source, translating it from SQL to the relevant language (in this case SoQL).
We also cache query responses on the DDN, but we run the DDN on multiple nodes so a CACHE_HIT is only guaranteed for subsequent queries that land on the same node.
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 (like this repository), 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, where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.
Mounting Data
This repository is an external repository. It's not hosted by Splitgraph. It is hosted by data.pa.gov, and Splitgraph indexes it. This means it is not an actual Splitgraph image, so you cannot use sgr clone to get the data. Instead, you can use the socrata adapter with the sgr mount command. Then, if you want, you can import the data and turn it into a Splitgraph image that others can clone.
First, install Splitgraph if you haven't already.
Mount the table with sgr mount
sgr mount socrata \
"pa-gov/governors-executive-budget-program-measures-sfy-tdq9-ue62" \
--handler-options '{
"domain": "data.pa.gov",
"tables": {
"governors_executive_budget_program_measures_sfy": "tdq9-ue62"
}
}'That's it! Now you can query the data in the mounted table like any other Postgres table.
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, pa-gov/governors-executive-budget-program-measures-sfy-tdq9-ue62 is just another Postgres schema.