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 local_law_8_of_2020_complaints_of_illegal_parking table in this repository, by referencing it like:
"cityofnewyork-us/local-law-8-of-2020-complaints-of-illegal-parking-cwy2-px8b:latest"."local_law_8_of_2020_complaints_of_illegal_parking"or in a full query, like:
SELECT
":id", -- Socrata column ID
"community_board", -- Provided by geo validation
"borough", -- Provided by the submitter and confirmed by geo validation
"address_type", -- Type of incident location information available
"open_data_channel_type", -- Indicates how the SR was submitted to 311, i.e. By Phone, Online, Mobile, Other or Unknown
"agency", -- Acronym of responding City Government Agency
"resolution_description", -- Describes the last action taken on the SR by the responding agency. May describe next or future steps
"street_name", -- Street name of incident address provided by the submitter
"complaint_type", -- This is the first level of a hierarchy identifying the topic of the incident or condition. Complaint Type may have a corresponding Descriptor (below) or may stand alone.
"location", -- Combination of the geo based lat & long of the incident location
"due_date", -- Date when responding agency is expected to update the SR. This is based on the Complaint Type and internal Service Level Agreements (SLAs)
"landmark", -- If the incident location is identified as a Landmark the name of the landmark will display here
"resolution_action_updated", -- Date when responding agency last updated the SR
"x_coordinate_state_plane", -- Geo validated, X coordinate of the incident location
"incident_zip", -- Incident location zip code, provided by geo validation
"y_coordinate_state_plane", -- Geo validated, Y coordinate of the incident location
"latitude", -- Geo based lat of the incident location
"closed_date", -- Date SR was closed by responding agency
"bbl", -- Borough Block and Lot, provided by geo validation. Parcel number to identify the location of location of buildings and properties in NYC
"intersection_street_1", -- First intersecting street based on geo validated incident location
"incident_address", -- House number of incident address provided by submitter
"cross_street_1", -- First cross street based on the geo validated incident location
"cross_street_2", -- Second cross street based on the geo validated incident location
"council_district", -- Provided by geo validation
"created_date", -- Date SR was created
"additional_details", -- This is associated to the Descriptor, and provides further detail on the incident or condition. Additional Details values are dependent on the Descriptor, and are not always required in SR.
"intersection_street_2", -- Second intersecting street based on geo validated incident location
"city", -- City of the incident location provided by geo validation
"longitude", -- Geo based long of the incident location
"location_type", -- Describes the type of location used in the address information
"agency_name", -- Full Agency name of responding City Government Agency
"unique_key", -- Unique identifier of a Service Request (SR) in the open data set
"descriptor", -- This is associated to the Complaint Type, and provides further detail on the incident or condition. Descriptor values are dependent on the Complaint Type, and are not always required in SR. Descriptor may have a corresponding Additional Details (below) or may stand alone.
"status", -- Status of SR submitted
":@computed_region_sbqj_enih",
":@computed_region_92fq_4b7q",
":@computed_region_yeji_bk3q",
":@computed_region_f5dn_yrer",
":@computed_region_efsh_h5xi"
FROM
"cityofnewyork-us/local-law-8-of-2020-complaints-of-illegal-parking-cwy2-px8b:latest"."local_law_8_of_2020_complaints_of_illegal_parking"
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 cityofnewyork-us/local-law-8-of-2020-complaints-of-illegal-parking-cwy2-px8b with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.cityofnewyork.us. When you querycityofnewyork-us/local-law-8-of-2020-complaints-of-illegal-parking-cwy2-px8b: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.cityofnewyork.us, 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 \
"cityofnewyork-us/local-law-8-of-2020-complaints-of-illegal-parking-cwy2-px8b" \
--handler-options '{
"domain": "data.cityofnewyork.us",
"tables": {
"local_law_8_of_2020_complaints_of_illegal_parking": "cwy2-px8b"
}
}'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, cityofnewyork-us/local-law-8-of-2020-complaints-of-illegal-parking-cwy2-px8b is just another Postgres schema.