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 attitudes_on_household_travel_surveys_edmonton table in this repository, by referencing it like:
"edmonton-ca/attitudes-on-household-travel-surveys-edmonton-gdrb-rdf9:latest"."attitudes_on_household_travel_surveys_edmonton"or in a full query, like:
SELECT
":id", -- Socrata column ID
"age_rollup_detailed_study_profiling_questionnaire_2014", -- Profiling question, Based on birthdate entered by Respondent. System Determined. Question: Age Rollup? - || Possible Answers: Under 15/15-17/18-24/25-29/30-34/35-39/40-44/45-49/50-54/55-59/60-64/65-69/70-74/75-79/80 and over
"fsa_study_profiling_questionnaire_2014", -- Forward Sortation Area (first 3 characters of postal code)
"q15_household_income_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - Which of the following categories best describes your total household income in 2014 before taxes? || Possible Answers: Under $20,000/$20,000 to $29,999/$30,000 to $39,999/$40,000 to $49,999/$50,000 to $59,999/$60,000 to $79,999/$80,000 to $99,999/$100,000 to $149,000/$150,000 and over/Prefer not to answer
"q14b_secondary_transportation_study_profiling_questionnaire_201", -- Profiling question, one response selected by respondent. - What is your secondary mode of transportation? || Possible Answers: Car/truck/Van as DRIVER/Car/truck/van as PASSENGER/Public Transit/Walk/Bicycle/Only have one mode of transportation/Other (Specify)
"q12_employment_status_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - What is your current employment status? || Possible Answers: Employed full-time (30+ hours a week)/Employed part-time (0-30 hours a week)/Homemaker/Post-secondary student/High School Student/Unemployed/Permanently unable to Work/Retired/Other (Specify)
"q10_own_business_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - Do you own a business in the City of Edmonton? || Possible Answers: Yes/No
"q9a_edmonton_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - How long have you lived in Edmonton? || Possible Answers: Less than 1 year/Between 1 to 2 years/Between 3 to 5 years/Greater than 5 years/I do not live in Edmonton
"gender_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - Are you…? || Possible Answers: Male/Female/Other/I prefer not to answer
"ostype", -- System Captured, OS used by the respondent. Question: OS Type? - OSType || Possible Answers: Mac (OS X)/Linux/Windows/iOS/Android/BlackBerry/Unknown
"importance_travel_survey_an_incentive_being_offered", -- Single response question, How important would each of the following attributes be in motivating you to participate in the household travel survey - An incentive being offered? || Possible Answers: 5 Extremely important/4 Very important/3 Moderately important/2 Slightly important/1 Not at all important
"importance_travel_survey_importance_of_the_survey_ultimate_use_", -- Single response question, How important would each of the following attributes be in motivating you to participate in the household travel survey - Importance of the survey/ ultimate use of the data? || Possible Answers: 5 Extremely important/4 Very important/3 Moderately important/2 Slightly important/1 Not at all important
"importance_travel_survey_shorter_time_commitment_to_complete_th", -- Single response question, How important would each of the following attributes be in motivating you to participate in the household travel survey - Shorter time commitment to complete the survey? || Possible Answers: 5 Extremely important/4 Very important/3 Moderately important/2 Slightly important/1 Not at all important
"importance_travel_survey_easy_to_use_survey_tool", -- Single response question, How important would each of the following attributes be in motivating you to participate in the household travel survey - Easy-to-use survey tool? || Possible Answers: 5 Extremely important/4 Very important/3 Moderately important/2 Slightly important/1 Not at all important
"rank_travel_survey_in_print_with_postage_paid_reply_envelope", -- Ranking question, If you were to participate in this survey, how would you most prefer to share your responses - In print with postage-paid reply envelope || Possible Answers: rank 1/rank 2/rank 3/rank 4/rank 5
"rank_travel_survey_in_person", -- Ranking question, If you were to participate in this survey, how would you most prefer to share your responses - In-person || Possible Answers: rank 1/rank 2/rank 3/rank 4/rank 5
"completiondate", -- Date/Time the respondent finished the survey.
"responsedate", -- Date/Time the respondent first opened/started the survey.
"q17_city_employee_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - Do you work for the City of Edmonton? || Possible Answers: Yes/No
"q11_home_language_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - What is the primary language spoken in your household? || Possible Answers: English/Arabic/Cantonese/Spanish/Panjabi (Punjabi)/French/German/Mandarin/Tagalog (Pilipino, Filipino)/Ukrainian/Other (Specify)
"household_travel_incentive_a_retail_gift_card_20", -- Single response question,If there was an incentive offered, how likely is it the following options would encourage you to participate - A retail gift card ($20)? || Possible Answers: Motivating/Not Motivating/Not sure
"rank_travel_survey_online_web_based", -- Ranking question, If you were to participate in this survey, how would you most prefer to share your responses - Online/web based? || Possible Answers: rank 1/rank 2/rank 3/rank 4/rank 5
"q8_born_canada_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - Were you born in Canada? || Possible Answers: Yes/No
"q13_volunteer_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - In the last 12 months, did you do any activities without pay on behalf of a group or an organization as a volunteer? || Possible Answers: Yes/No
"importance_travel_survey_convenient_way_to_access_the_survey", -- Single response question, How important would each of the following attributes be in motivating you to participate in the household travel survey - Convenient way to access the survey? || Possible Answers: 5 Extremely important/4 Very important/3 Moderately important/2 Slightly important/1 Not at all important
"rank_travel_survey_mobile_phone_or_tablet", -- Ranking question, If you were to participate in this survey, how would you most prefer to share your responses - Mobile phone or tablet? || Possible Answers: rank 1/rank 2/rank 3/rank 4/rank 5
"household_travel_incentive_cash_20", -- Single response question,If there was an incentive offered, how likely is it the following options would encourage you to participate - Cash ($20)? || Possible Answers: Motivating/Not Motivating/Not sure
"devicetype", -- System Captured, Device used by the respondent. Question: Device Type? - DeviceType || Possible Answers: Tablet/Desktop/Phone
"q3_own_rent_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - Do you own or rent your primary residence in the City of Edmonton? || Possible Answers: Own/Rent
"q7_children_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - Do you have children 18 or under living at home? || Possible Answers: Yes/No
"household_travel_incentive_an_entry_into_a_draw_for_a_larger_pr", -- Single response question,If there was an incentive offered, how likely is it the following options would encourage you to participate - An entry into a draw for a larger prize (ie: iPad)? || Possible Answers: Motivating/Not Motivating/Not sure
"browsertype", -- System Captured, Browser used by the respondent. Question: Browser Type? - BrowserType || Possible Answers: Internet Explorer/Firefox/Safari/Google Chrome/Opera/Android/BlackBerry/Unknown
"household_travel_incentive_an_entry_into_a_draw_for_a_one_month", -- Single response question,If there was an incentive offered, how likely is it the following options would encourage you to participate - An entry into a draw for a one-month ETS pass? || Possible Answers: Motivating/Not Motivating/Not sure
"household_travel_incentive_a_retail_gift_card_10", -- Single response question,If there was an incentive offered, how likely is it the following options would encourage you to participate - A retail gift card ($10)? || Possible Answers: Motivating/Not Motivating/Not sure
"likelihood_travel_survey_household_travel_survey_participation", -- Single response question, How likely is it that your household would participate in a study that involved completing a diary of your household's trips over the course of one day? || Possible Answers: 5 Definitely/4 Very likely/3 Moderately likely/2 Slightly likely/1 Not likely
"rank_travel_survey_telephone", -- Ranking question, If you were to participate in this survey, how would you most prefer to share your responses - Telephone || Possible Answers: rank 1/rank 2/rank 3/rank 4/rank 5
"q14a_primary_transportation_study_profiling_questionnaire_2014", -- Profiling question, one response selected by respondent. - What is your primary mode of transportation? || Possible Answers: Car/truck/Van as DRIVER/Car/truck/van as PASSENGER/Public Transit/Walk/Bicycle/Other (Specify)
"q16_education_study_profiling_questionnaire_2014" -- Profiling question, one response selected by respondent. - What is the highest level of education you have completed? || Possible Answers: Elementary/grade school graduate/High school graduate/College / technical school graduate/University undergraduate degree/Post-graduate degree/Professional school graduate (e.g. medicine, dentistry, veterinary medicine, optometry)
FROM
"edmonton-ca/attitudes-on-household-travel-surveys-edmonton-gdrb-rdf9:latest"."attitudes_on_household_travel_surveys_edmonton"
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 edmonton-ca/attitudes-on-household-travel-surveys-edmonton-gdrb-rdf9 with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.edmonton.ca. When you queryedmonton-ca/attitudes-on-household-travel-surveys-edmonton-gdrb-rdf9: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.edmonton.ca, 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 \
"edmonton-ca/attitudes-on-household-travel-surveys-edmonton-gdrb-rdf9" \
--handler-options '{
"domain": "data.edmonton.ca",
"tables": {
"attitudes_on_household_travel_surveys_edmonton": "gdrb-rdf9"
}
}'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, edmonton-ca/attitudes-on-household-travel-surveys-edmonton-gdrb-rdf9 is just another Postgres schema.