norfolk-gov/plan-reviews-dhk3-hr4y
Icon for Socrata external plugin

Query the Data Delivery Network

Query the DDN

The 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 plan_reviews table in this repository, by referencing it like:

"norfolk-gov/plan-reviews-dhk3-hr4y:latest"."plan_reviews"

or in a full query, like:

SELECT
    ":id", -- Socrata column ID
    "completed_date", -- The date that the review was completed.
    "type", -- The category or nature of the review, which may include Building Codes, CBPA (Chesapeake Bay Preservation Area) Review, Stormwater, Plan Review, Floodplain Review, Surveys, Design Review, Reservoir Review, Environmental Review, and others.
    "tax_account", -- The tax account number linked to the property or parcel associated with the review for tax assessment purposes.
    "gpin", -- A specific identifier for the parcel or land associated with the review within the City's grid system.
    "permit_or_land_use_application", -- The permit or land use application number to which the review is associated, linking the review to a specific construction or development project.
    "address", -- The physical location or street address to which the review is assigned.
    "status", -- The current stage or status of the review within the review process. Possible statuses may include Pending, Mitigation Required, Disapproved, Approved, etc.
    "due_date", -- The deadline or date by which the review is expected to be completed. It serves as a timeline for the review process.
    "review_number" -- A unique identifier assigned to the review for tracking and reference purposes.
FROM
    "norfolk-gov/plan-reviews-dhk3-hr4y:latest"."plan_reviews"
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/plan-reviews-dhk3-hr4y 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/plan-reviews-dhk3-hr4y: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

Install Splitgraph Locally
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/plan-reviews-dhk3-hr4y" \
  --handler-options '{
    "domain": "data.norfolk.gov",
    "tables": {
        "plan_reviews": "dhk3-hr4y"
    }
}'

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/plan-reviews-dhk3-hr4y is just another Postgres schema.