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 city_clerk table in this repository, by referencing it like:
"citydata-mesaaz-gov/city-clerk-tf5h-bcv2:latest"."city_clerk"or in a full query, like:
SELECT
":id", -- Socrata column ID
"requests_for_information", -- Total number of requests received (from the public or internally) for information that is non-election related.
"legal_ads_published", -- Legal Ads Published
"hours_in_attendance_at_council_meeting", -- Hours in attendance at Council meeting
"inquiries_tasks_related_to_advisory_boards_and_committees", -- Total number of inquiries made, or tasks performed related to the management of Advisory Boards and Committees.
"psprs_retirement_and_drop", -- Refers to participants in the Public Safety Personnel Retirement System (PSPRS) and Deferred Retirement Option Plan (DROP). Total number of retirement applications received from Sworn Police and Fire employees and processed within the month they are discussed and considered by the Fire and/or Police Pension Boards.
"notaries_performed", -- Total number of notary services provided by the City Clerk’s Office.
"requests_for_election_related_information_and_voter_assistance", -- Total number of calls received that were specifically related to election information and/or voter assistance
"public_records_requests_for_clerk_office", -- Total number of public record requests submitted to the City of Mesa, excluding those for the Police Department and Development Services.
"community_engagement_activities_attended", -- Community Engagement Activities attended
"year", -- Year
"in_person_early_votes", -- Total number of early voters who visit the City Clerk’s office to cast votes in-person during the early voting period.
"hours_spent_transcribing_council_minutes", -- Hours spent transcribing Council minutes
"public_safety_disability", -- Total number of Accidental or Ordinary Disability Retirement applications received and processed by Sworn Police and Fire employees. The applications are also counted within the month they are discussed and considered by the Fire and/or Police Pension Boards.
"percent_of_registered_voters_voting_in_primary_general", -- Percent of Registered Voters voting in Primary/General
"projects_tasks_related_to_govqa_software_management", -- Total number of research projects, tasks, and updates made related to managing the GovQA software.
"special_projects_and_research_projects", -- Unique projects that fall outside of normal daily duties.
"public_records_requests_city_processed_through_govqa", -- Total number of public record requests received for the City Clerk’s Office to satisfy
"legal_service_documents", -- Total number of summons, claims, subpoenas, and garnishments submitted to the City Clerk's Office and forwarded to City Attorney's Office within 24 hours.
"special_projects_and_research_projects_hours", -- Special Projects and Research Projects - Hours
"election_web_pages_accessed", -- Total number of unique visits to the City Clerks' Election web pages.
"council_minutes_posted", -- Total number of Council meeting minutes posted for the public within two working days after Council approval, which is in compliance with the Open Meeting Law (regular, special, committee, budget).
"election_pamphlets_mailed", -- Total number of publicity pamphlets mailed to registered households, as required by law to ensure voters receive them prior to the start of early voting. The number fluctuates by year based on whether it is an election year.
"records_retention_inquiries", -- Total number of requests for assistance received from other City staff pertaining to records retention schedules and information.
"candidate_and_committee_filings", -- Candidate and Committee Filings
"date", -- Month Year format
"month", -- Month
"public_meeting_notices", -- Total number of meeting notices (boards, committees, etc.) posted in compliance with the Open Meeting Law, which is no less than 24-hours prior to the meeting being held.
"advisory_board_committee_applications_submitted", -- Total number of applications submitted for City of Mesa Advisory Boards or Committees.
"ordinances_published_after_council_adoption" -- Ordinances Published after Council Adoption
FROM
"citydata-mesaaz-gov/city-clerk-tf5h-bcv2:latest"."city_clerk"
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 citydata-mesaaz-gov/city-clerk-tf5h-bcv2 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 citydata-mesaaz-gov/city-clerk-tf5h-bcv2: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 citydata-mesaaz-gov/city-clerk-tf5h-bcv2Checkout 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 citydata-mesaaz-gov/city-clerk-tf5h-bcv2:latestThis will download all the objects for the latest tag of citydata-mesaaz-gov/city-clerk-tf5h-bcv2 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 citydata-mesaaz-gov/city-clerk-tf5h-bcv2: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 citydata-mesaaz-gov/city-clerk-tf5h-bcv2: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, citydata-mesaaz-gov/city-clerk-tf5h-bcv2 is just another Postgres schema.