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_property_use", -- The current property use of the building to be altered.
"leed_certification", -- Do you plan to pursue Leadership in Energy and Environmental Design Certification?
"commercial_sewer_connection", -- Number of commercial sewer connections from the project
"outbuilding_description",
"reconstruction_or_change", -- Reconstruction or change to any existing exterior building element (porch, deck, etc.)
"building_construction_type",
"proposed_loading_bays", -- Number of Proposed Loading Bays
"existing_off_street_bicycle_parking_long_term", -- Number of Existing Off-Street Bicycle Parking Spaces (Long Term)
"other_cooking_equipment",
"planning_board", -- Is this application subject to a Planning Board Special Permit?
"basement_plumbing", -- Will the proposed work result in the addition or replacement of basement plumbing fixture?
"proposed_off_street_bicycle_parking_short_term", -- Number of Proposed Off-Street Bicycle Parking Spaces (Short Term)
"change_residential_units", -- Will the number of residential units change as a result of this permit?
"address_geocoded_address",
"excavation_of_a_basement",
"size_of_the_new_addition", -- Size of new addition in gross square feet
"storm_sewer", -- Will the proposed work result in new, abandoned, or replaced sanitary storm sewer connections?
"stories_above_grade",
"cooking_equipment_type",
"bza_number",
"condo_association", -- Is the property part of a condo association?
"applicant_submit_date", -- Applicant submit date
"number_of_units_to_be_removed", -- Number of units to be removed
"building_cost_of_construction", -- Building Cost of Construction
"food_establishment", -- Will the proposed work result in a new or renovated food establishment?
"hers_rating", -- Do you intend to obtain a Home Energy Rating (HERS)?
"firm_name", -- Name of the firm performing the addition or alteration
"description_of_demolition",
"exterior_stairs_type",
"gross_square_footage",
"proposed_off_street_bicycle_parking_long_term", -- Number of Proposed Off-Street Bicycle Parking Spaces (Long Term)
"existing_off_street_vehicle_parking", -- Number of Existing Off-Street Vehicle Parking Spaces
"off_street_parking", -- Number of Proposed Off-Street Vehicle Parking Spaces
"building_use",
"building_height_feet", -- Building height in feet
"construction_debris_will", -- Construction debris will be disposed at/by:
"dewatering", -- Will the proposed work require construction dewatering during any phase of the project?
"energy_code", -- Which energy code compliance option do you intend to take?
"fire_prevention_cost_of", -- Fire Prevention Cost of Construction
"hvac_cost_of_construction", -- HVAC Cost of Construction
"final_cost_of_construction", -- Final Cost of Construction
"gas_cost_of_construction", -- Gas Cost of Construction
"electrical_cost_of", -- Electrical Cost of Construction
"issue_date", -- Date permit was issued
"longitude",
"latitude",
"address_geocoded_city",
"address_geocoded", -- Address along with latitude and longitude coordinates for mapping data within the Socrata open data platform.
"address", -- City address where the work will take place.
"id",
"exterior_stairs",
"planning_board_number",
":@computed_region_e4yd_rwk4",
":@computed_region_rffn_qbt6",
":@computed_region_v7jj_366k",
":@computed_region_guic_hr4a",
":@computed_region_swkg_bavi",
"drains", -- Addition or alteration of a roof or foundation drain that discharges to the City’s sanitary sewer or storm water system
"certificate_of_occupancy", -- Is a certificate of occupancy required for this project?
"address_geocoded_state",
"public_right", -- Will the proposed work result in a new, abandoned or modified curb cut into the public right-of-way?
"bza", -- Is this application subject to a Board of Zoning Appeal (BZA) Case?
"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?
"existing_off_street_bicycle_parking_short_term", -- Number of Existing Off-Street Bicycle Parking Spaces (Short Term)
"open_air_cafe", -- Will the food establishment include open air cafe windows?
"floor_area_change", -- Will the work result in any changes to the floor area or any dimensional changes to the building?
"openings_or_doors", -- Create new openings for any window, door, or skylight
"curb_cut", -- Is there an existing curb cut?
"large_area_change", -- Will the project add and/or alter 25,000 square feet or more of gross building area?
"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
"residential_sewer_connection", -- Number of residential sewer connections from the project
"type_of_demolition",
"address_geocoded_zip",
"detailed_description_of_work", -- Detailed Description of Work
"off_street_parking_change",
"finish_materials", -- Describe the finish materials for the floor, walls, ceiling and cove
"bicycle_change", -- Will the proposed work alter the number or type of available vehicle or bicycle parking spaces?
"location_of_deck",
"exterior_change", -- Does the proposed work change or alter any part of the building's exterior?
"industrial_sewer_connection", -- Number of industrial sewer connections from the project
"proposed_property_use", -- The proposed property use of the building to be altered.
"will_the_property_use_change", -- Will the property use change as a result of this permit?
"total_cost_of_construction", -- Total Cost of Construction
"construction_of_a_deck", -- Construction of a deck (including roof decks)
"porch_balcony_dormer", -- Construction of dormers, bays, balconies, landings and/or porches
"change_any_floor_or_ceiling", -- Change any floor or ceiling height
"outbuilding", -- Erect an outbuilding (ex: shed or garage)
"owner_occupied", -- Is the property owner-occupied?
"status", -- Active permits are still in the process of being submitted. Complete permits have been submitted.
"current_number_of_dwelling", -- Current Number of Dwelling Units
"unit_increase" -- Proposed Number of Dwelling Units (Increase)
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.
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, 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 (like this repository), where the author has pushed Splitgraph Images to the repository, you can "clone" and/or "checkout" the data using sgr cloneand sgr checkout.
Cloning Data
Because cambridgema-gov/building-permits-additionalteration-qu2z-8suj:latest is a Splitgraph Image, you can clone the data from Spltgraph Cloud to your local engine, where you can query it like any other Postgres database, using any of your existing tools.
First, install Splitgraph if you haven't already.
Clone the metadata with sgr clone
This will be quick, and does not download the actual data.
sgr clone cambridgema-gov/building-permits-additionalteration-qu2z-8sujCheckout the data
Once you've cloned the data, you need to "checkout" the tag that you want. For example, to checkout the latest tag:
sgr checkout cambridgema-gov/building-permits-additionalteration-qu2z-8suj:latestThis will download all the objects for the latest tag of cambridgema-gov/building-permits-additionalteration-qu2z-8suj and load them into the Splitgraph Engine. Depending on your connection speed and the size of the data, you will need to wait for the checkout to complete. Once it's complete, you will be able to query the data like you would any other Postgres database.
Alternatively, use "layered checkout" to avoid downloading all the data
The data in cambridgema-gov/building-permits-additionalteration-qu2z-8suj:latest is 0 bytes. If this is too big to download all at once, or perhaps you only need to query a subset of it, you can use a layered checkout.:
sgr checkout --layered cambridgema-gov/building-permits-additionalteration-qu2z-8suj:latestThis will not download all the data, but it will create a schema comprised of foreign tables, that you can query as you would any other data. Splitgraph will lazily download the required objects as you query the data. In some cases, this might be faster or more efficient than a regular checkout.
Read the layered querying documentation to learn about when and why you might want to use layered queries.
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.