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 building_permits_additionalteration table in this repository, by referencing it like:
"cambridgema-gov/building-permits-additionalteration-qu2z-8suj:latest"."building_permits_additionalteration"or in a full query, like:
SELECT
":id", -- Socrata column ID
"current_number_of_dwelling", -- Current Number of Dwelling Units
"change_residential_units", -- Will the number of residential units change as a result of this permit?
"building_cost_of_construction", -- Building Cost of Construction
":@computed_region_guic_hr4a",
"exterior_change", -- Does the proposed work change or alter any part of the building's exterior?
"existing_off_street_bicycle_parking_short_term", -- Number of Existing Off-Street Bicycle Parking Spaces (Short Term)
":@computed_region_v7jj_366k",
":@computed_region_rffn_qbt6",
":@computed_region_swkg_bavi",
"food_establishment", -- Will the proposed work result in a new or renovated food establishment?
"planning_board", -- Is this application subject to a Planning Board Special Permit?
"cooking_equipment_type",
"construction_of_a_deck", -- Construction of a deck (including roof decks)
"building_use",
":@computed_region_e4yd_rwk4",
"fire_prevention_cost_of", -- Fire Prevention Cost of Construction
"total_cost_of_construction", -- Total Cost of Construction
"unit_increase", -- Proposed Number of Dwelling Units (Increase)
"final_cost_of_construction", -- Final Cost of Construction
"floor_area_change", -- Will the work result in any changes to the floor area or any dimensional changes to the building?
"hers_rating", -- Do you intend to obtain a Home Energy Rating (HERS)?
"openings_or_doors", -- Create new openings for any window, door, or skylight
"firm_name", -- Name of the firm performing the addition or alteration
"reconstruction_or_change", -- Reconstruction or change to any existing exterior building element (porch, deck, etc.)
"bza_number",
"number_of_residential_units", -- Number of residential units to be added
"unit_decrease", -- Proposed Number of Dwelling Units (Decrease)
"plumbing_cost_of_construction", -- Plumbing Cost of Construction
"construction_debris_will", -- Construction debris will be disposed at/by:
"porch_balcony_dormer", -- Construction of dormers, bays, balconies, landings and/or porches
"exterior_stairs",
"outbuilding", -- Erect an outbuilding (ex: shed or garage)
"drains", -- Addition or alteration of a roof or foundation drain that discharges to the City’s sanitary sewer or storm water system
"proposed_loading_bays", -- Number of Proposed Loading Bays
"building_construction_type",
"proposed_off_street_bicycle_parking_long_term", -- Number of Proposed Off-Street Bicycle Parking Spaces (Long Term)
"residential_sewer_connection", -- Number of residential sewer connections from the project
"type_of_demolition",
"industrial_sewer_connection", -- Number of industrial sewer connections from the project
"address_geocoded_zip",
"detailed_description_of_work", -- Detailed Description of Work
"off_street_parking_change",
"curb_cut", -- Is there an existing curb cut?
"existing_off_street_vehicle_parking", -- Number of Existing Off-Street Vehicle Parking Spaces
"finish_materials", -- Describe the finish materials for the floor, walls, ceiling and cove
"address_geocoded", -- Address along with latitude and longitude coordinates for mapping data within the Socrata open data platform.
"bicycle_change", -- Will the proposed work alter the number or type of available vehicle or bicycle parking spaces?
"location_of_deck",
"longitude",
"gas_cost_of_construction", -- Gas Cost of Construction
"current_property_use", -- The current property use of the building to be altered.
"basement_plumbing", -- Will the proposed work result in the addition or replacement of basement plumbing fixture?
"condo_association", -- Is the property part of a condo association?
"size_of_the_new_addition", -- Size of new addition in gross square feet
"large_area_change", -- Will the project add and/or alter 25,000 square feet or more of gross building area?
"dewatering", -- Will the proposed work require construction dewatering during any phase of the project?
"existing_off_street_bicycle_parking_long_term", -- Number of Existing Off-Street Bicycle Parking Spaces (Long Term)
"other_cooking_equipment",
"planning_board_number",
"issue_date", -- Date permit was issued
"commercial_sewer_connection", -- Number of commercial sewer connections from the project
"storm_sewer", -- Will the proposed work result in new, abandoned, or replaced sanitary storm sewer connections?
"change_any_floor_or_ceiling", -- Change any floor or ceiling height
"building_height_feet", -- Building height in feet
"proposed_off_street_bicycle_parking_short_term", -- Number of Proposed Off-Street Bicycle Parking Spaces (Short Term)
"address_geocoded_address",
"hvac_cost_of_construction", -- HVAC Cost of Construction
"owner_occupied", -- Is the property owner-occupied?
"description_of_demolition",
"id",
"number_of_units_to_be_removed", -- Number of units to be removed
"outbuilding_description",
"gross_square_footage",
"applicant_submit_date", -- Applicant submit date
"electrical_cost_of", -- Electrical Cost of Construction
"certificate_of_occupancy", -- Is a certificate of occupancy required for this project?
"stories_above_grade",
"address", -- City address where the work will take place.
"latitude",
"will_the_property_use_change", -- Will the property use change as a result of this permit?
"address_geocoded_state",
"proposed_property_use", -- The proposed property use of the building to be altered.
"public_right", -- Will the proposed work result in a new, abandoned or modified curb cut into the public right-of-way?
"leed_certification", -- Do you plan to pursue Leadership in Energy and Environmental Design Certification?
"excavation_of_a_basement",
"bza", -- Is this application subject to a Board of Zoning Appeal (BZA) Case?
"address_geocoded_city",
"status", -- Active permits are still in the process of being submitted. Complete permits have been submitted.
"exterior_stairs_type",
"energy_code", -- Which energy code compliance option do you intend to take?
"impervious_cover", -- Will the proposed work result in an increase to the property’s impervious cover?
"method_of_removal", -- Method for removing debris from the demolition
"half_area", -- Will the proposed work renovate over 50% of the total building area, with 10 or more fixtures replaced or installed?
"off_street_parking", -- Number of Proposed Off-Street Vehicle Parking Spaces
"open_air_cafe" -- Will the food establishment include open air cafe windows?
FROM
"cambridgema-gov/building-permits-additionalteration-qu2z-8suj:latest"."building_permits_additionalteration"
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 cambridgema-gov/building-permits-additionalteration-qu2z-8suj with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.cambridgema.gov. When you querycambridgema-gov/building-permits-additionalteration-qu2z-8suj: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.cambridgema.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 \
"cambridgema-gov/building-permits-additionalteration-qu2z-8suj" \
--handler-options '{
"domain": "data.cambridgema.gov",
"tables": {
"building_permits_additionalteration": "qu2z-8suj"
}
}'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, cambridgema-gov/building-permits-additionalteration-qu2z-8suj is just another Postgres schema.