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 311_call_centre_satisfaction_survey_2014 table in this repository, by referencing it like:
"edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha:latest"."311_call_centre_satisfaction_survey_2014"or in a full query, like:
SELECT
":id", -- Socrata column ID
"q16m1", -- Thinking overall about the 311 service, do you have any suggestions about how to improve it?
"d3", -- In which of the following age categories do you belong? Please stop me when I read the correct one.
"q12m4", -- Even though the information might be available on the City website, why did you choose to call 311 instead of looking through the City website? Is it because… Response 4
"qs1", -- Have you called / contacted 311 services over the telephone in the past six months?
"qs2", -- How many times have you called 311 services in the past six months?
"q11m7", -- Why did you choose to call 311? Is it because… Response 7
"q3h", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. Your reason for calling was resolved in a timely manner
"q3f", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. The agent was knowledgeable
"q3a", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. The ease of contacting 311
"d1", -- GENDER
"qs4", -- And what was the purpose of your most recent call to 311? Was it…?
"q12m2", -- Even though the information might be available on the City website, why did you choose to call 311 instead of looking through the City website? Is it because… Response 2
"q12m3", -- Even though the information might be available on the City website, why did you choose to call 311 instead of looking through the City website? Is it because… Response 3
"q16m2", -- Thinking overall about the 311 service, do you have any suggestions about how to improve it? Response 2
"q1", -- Please only consider your last call experience with 311 while providing your opinions. Overall, how satisfied were you with your experience with the most recent call to 311?
"postal",
"q16m3", -- Thinking overall about the 311 service, do you have any suggestions about how to improve it? Response 3
"qs3m3", -- What was the purpose of your call / calls to 311 in the past six months? Response 3
"qs3m4", -- What was the purpose of your call / calls to 311 in the past six months? Response 4
"qs3m1", -- What was the purpose of your call / calls to 311 in the past six months?
"qs3m5", -- What was the purpose of your call / calls to 311 in the past six months? Response 5
"q3c", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. The agent was helpful
"q3e", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. The agent was courteous and professional
"q4om2", -- IF SOMEWHAT OR COMPLETELY DISAGREE IN Q4 – Why do you say so? Response 2
"q3d", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. The information provided was accurate
"q4", -- To what extent do you agree or disagree to the following statement... 311 makes it convenient for Edmontonians to obtain information or seek the service that they want.
"q4om1", -- IF SOMEWHAT OR COMPLETELY DISAGREE IN Q4 – Why do you say so?
"q11m3", -- Why did you choose to call 311? Is it because… Response 3
"q11m4", -- Why did you choose to call 311? Is it because… Response 4
"q11m2", -- Why did you choose to call 311? Is it because… Response 2
"q11m5", -- Why did you choose to call 311? Is it because… Response 5
"q11m6", -- Why did you choose to call 311? Is it because… Response 6
"q10", -- Did you check for information about <QS4> on the City website?
"qs3m2", -- What was the purpose of your call / calls to 311 in the past six months? Response 2
"q5", -- You said that you had called 311 <QS2> times. Thinking about the most recent call to 311, were you calling to follow up on an earlier issue or enquiry...
"q9m2", -- Do you know about the City of Edmonton website and 311 online? Response 2
"q2m1", -- Why were you <Q1> with your most recent call experience?
"q3b", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. The length of time it took to reach a 311 agent
"q2m2", -- Why were you <Q1> with your most recent call experience? Response 2
"q2m3", -- Why were you <Q1> with your most recent call experience? Response 3
"q3g", -- Again, thinking about your most recent call to 311, how satisfied were you on the following aspects of your last call. The agent processed your call promptly, without a lengthy wait or hold period
"q6m1", -- Tell us why you had to call back on the same issue..
"q6m2", -- Tell us why you had to call back on the same issue. Response 2
"q6m3", -- Tell us why you had to call back on the same issue. Response 3
"q9m1", -- Do you know about the City of Edmonton website and 311 online?
"q11m1", -- Why did you choose to call 311? Is it because...
"q12m1" -- Even though the information might be available on the City website, why did you choose to call 311 instead of looking through the City website? Is it because...
FROM
"edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha:latest"."311_call_centre_satisfaction_survey_2014"
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/311-call-centre-satisfaction-survey-2014-6asu-htha 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 edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha: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 edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-hthaCheckout 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 edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha:latestThis will download all the objects for the latest tag of edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha 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 edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha: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 edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha: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, edmonton-ca/311-call-centre-satisfaction-survey-2014-6asu-htha is just another Postgres schema.