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 animals_inventory table in this repository, by referencing it like:
"dallasopendata/animals-inventory-qgg6-h4bd:latest"."animals_inventory"or in a full query, like:
SELECT
":id", -- Socrata column ID
"animal_stay_days", -- Number of days the animal has been in the shelter
"intake_subtype", -- sub-reason or detailed reason why the animal was impounded
"census_tract", -- Census tract numbers
"source_id", -- Auto generated number assigned to a person who found the animal, turned the animal in or the person from whom DAS picked up the animal
"activity_number", -- Auto generated number assigned to a field animal rescued from field incidents to the shelter
"kennel_status", -- Status of the animal during its stay at the shelter; depends on the services provided to the animal during its stay at the shelter
"year", -- Added column to improve visualization of activities by specific fiscal years
"additional_information", -- Staffs comments and notes related to services provided to specific animals at various stages
"outcome_condition", -- The condition of the animal when the animal leaves the shelter with respect to the Asilomar Accord
"intake_date", -- The date of impoundment or when the animal was admitted into the shelter
"intake_type", -- Reason why the animal was impounded
"kennel_number", -- Kennel number in which the animal is housed at the shelter
"animal_id", -- System auto generated number, unique to every animal impounded
"due_out", -- Date at which the animal is due for review
"intake_time", -- The time at which the animal was impounded or admitted into the shelter
"animal_breed", -- Record the animal breed or wildlife
"impound_number", -- Auto generated number by the Chameleon software for record keeping
"reason", -- Reason provided by the animal's owners as to why they are giving up their pet to DAS
"activity_sequence", -- This represents the sequence for the activity/call, and one activity/call can have multiple sequence.
"hold_request", -- This contains any hold requests that have been made concerning the animal
"staff_id", -- Impounding staff initials
"council_district", -- Council District number where the animal was reported/found
"receipt_number", -- Auto generated number by Chameleon when a transaction occurs, such as adoption or redemption
"outcome_type", -- Final disposition of the animal
"animal_origin", -- Comments related to the origin of the animal impounded
"month", -- Added column to improve visualization of activities by month
"animal_type", -- Record of the type of animal
"outcome_time", -- The time of the outcome of the animal
"intake_condition", -- The condition of the animal when it is impounded with respect to the Asilomar Accord
"chip_status", -- Results of animal being scanned for microchip
"tag_type", -- Types of the tags include but may not be limited to microchip, rabies, and/or registration tag that is assign by DAS
"service_request_number", -- Number auto generated by 3-1-1 when a call comes in for services
"outcome_date" -- The date of the outcome of the animal
FROM
"dallasopendata/animals-inventory-qgg6-h4bd:latest"."animals_inventory"
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 dallasopendata/animals-inventory-qgg6-h4bd with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at www.dallasopendata.com. When you querydallasopendata/animals-inventory-qgg6-h4bd: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 www.dallasopendata.com, 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 \
"dallasopendata/animals-inventory-qgg6-h4bd" \
--handler-options '{
"domain": "www.dallasopendata.com",
"tables": {
"animals_inventory": "qgg6-h4bd"
}
}'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, dallasopendata/animals-inventory-qgg6-h4bd is just another Postgres schema.