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 permits table in this repository, by referencing it like:
"norfolk-gov/permits-fahm-yuh4:latest"."permits"or in a full query, like:
SELECT
":id", -- Socrata column ID
"use_class", -- The classification indicating whether the permit pertains to a commercial or residential property.
"tax_abatement", -- Indicates if the permit project includes a tax abatement: https://www.norfolk.gov/4816/Tax-Abatement-Program
"use_type", -- The classification specifying the intended use of the permit, including commercial, manufactured homes, manufactured office, multifamily dwelling, one/two family dwelling, etc.
"code_edition", -- The year edition of the code book being referenced for compliance (2003, 2006, 2009, 2011, 2012, 2014, 2015, 2018)
"location", -- A combination of Longitude and Latitude to allow for mapping in the Open Data Portal.
"use_group", -- The designation indicating how the structure will be utilized, such as R-5 Single Family Residence, A-2 N Nightclubs, R-1 Hotel/motel, R-2 Apts/Dormitories, F-2 Low-hazard factory, etc.
"total_fee", -- The sum of all fees associated with the permit.
"longitude", -- The longitude of the parcel.
"address", -- The physical location or street address to which the permit is assigned.
"gpin", -- A specific identifier for the parcel or land associated with the permit within the City's grid system.
"status", -- The current stage or status of the permit within the approval process, including "New", "Issued", "Finaled", "Approved", "Withdrawn", "Pending", "Incomplete", "Overdue", "Revoked", etc.
"code_book", -- The specific building code book or set of regulations governing the permit (NEC, VA Rehab, VCC, VEBC, VMC, VPC, VRC).
"construction_type", -- A code indicating the level of fire resistance and structural elements incorporated into the construction of the building or structure (1A, 1B, 2A, 2B, 3A, 3B, 4, 5A, 5B).
"permit_number", -- A unique identifier assigned to the permit for tracking and reference purposes.
"parent_permit_number", -- The identifier of any overarching permit, if applicable, which may encompass multiple individual permits.
"tax_account", -- The tax account number linked to the property or parcel associated with the permit for tax assessment purposes.
"latitude", -- The latitude of the parcel.
"type", -- The category or nature of the permit, such as building, demolition, electrical, plumbing, sign, etc.
"work_type", -- The specific type of work that the permit authorizes, such as new construction, replacement, minor addition, demolition, asbestos abatement, etc.
"structure", -- The type of structure for which the permit is issued, such as building, driveway, fence, day care home, elevator, accessory structure, sprinkler system, tent, underground tank, etc.
"application_date", -- The date when the initial permit application was submitted.
"issue_date", -- The date when the permit was officially issued, allowing construction or related activities to commence.
"expiration_date", -- The date until which the issued building permit remains valid.
"finaled_date", -- The date when the permit was finalized, indicating that all required inspections have been completed and approved.
"total_payments", -- The total payments made to date for the permit.
"total_balance", -- The total balance due on the permit.
"project_cost", -- An estimate of the overall cost of the project or construction work for which the permit was issued.
"square_footage", -- The total area, measured in square feet, of the project or structure to which the permit pertains.
"next_annual_inspection", -- If required, the date of the next scheduled annual inspection for the permit.
"next_five_year_inspection", -- The date on which the next five-year inspection is due for the permit.
":@computed_region_25t2_rbz7", -- This column was automatically created in order to record in what polygon from the dataset 'US Counties' (25t2-rbz7) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
":@computed_region_x6fk_ihs5" -- This column was automatically created in order to record in what polygon from the dataset 'Civic Leagues' (x6fk-ihs5) the point in column 'location' is located. This enables the creation of region maps (choropleths) in the visualization canvas and data lens.
FROM
"norfolk-gov/permits-fahm-yuh4:latest"."permits"
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 norfolk-gov/permits-fahm-yuh4 with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.norfolk.gov. When you querynorfolk-gov/permits-fahm-yuh4: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.norfolk.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 \
"norfolk-gov/permits-fahm-yuh4" \
--handler-options '{
"domain": "data.norfolk.gov",
"tables": {
"permits": "fahm-yuh4"
}
}'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, norfolk-gov/permits-fahm-yuh4 is just another Postgres schema.