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 births table in this repository, by referencing it like:
"delaware-gov/births-2k3z-2ap9:latest"."births"or in a full query, like:
SELECT
":id", -- Socrata column ID
"count", -- This column has been added strictly to be able to count records for summaries and visualizations. The value will always be "1".
"mom_s_race", -- Race data are grouped for purposes of data analysis into the following categories established by NCHS: White, Black, Other (American Indian/Aleut/Eskimo and Asian & Pacific Islander {Chinese, Japanese, Hawaiian, Filipino and Other Asian or Pacific Islander}).
"gender", -- Gender
"county_of_residence", -- Mother's county of residence.
"live_birth_order", -- Live Birth Order indicates the numeric relationship of a newborn child to other children born alive to the mother during previous deliveries.
"mom_s_age", -- Mother’s age is divided into three groupings; less than twenty years of age, twenty to thirty four years of age, and thirty five years and older.
"state_of_residence", -- Mother's state of residence
"place_of_birth", -- Place of birth is the type of facility or place where the birth occurred such as hospital, birthing center, home, en route, or other.
"mom_s_marital_status", -- Mother's marital status
"mom_s_hispan", -- Mother is of Hispanic origin (Yes or No). This question is considered to be separate from the Race question.
"mom_s_education", -- Mother’s Educational Attainment or the highest level of formal education completed. Education is divided into three groupings; under grade twelve, high school graduate or equivalent (GED), and one or more years of college.
"mode_of_delivery", -- Method of Delivery in two groups: vaginal or cesarean section.
"year", -- Year of birth
"payment", -- Source of Payment for delivery (private insurance, Medicaid, and self pay)
"gestation", -- Gestation is the number of weeks elapsed between the first day of the last normal menstrual period (LMP) and the date of birth. When the date of the LMP is incompletely reported or the length of gestation as computed from the LMP is inconsistent with the reported birth weight, the "clinical estimate of gestation" is used. Preterm is less than 37 weeks. Term is 37 weeks to 41 weeks. Post-term is more than 42 weeks.
"birth_weight", -- Birthweight is the first weight of the fetus or newborn obtained after birth. This weight should be measured within the first hour of life before significant postnatal weight loss has occurred. Birthweight is measured in grams and divided into three groups; less than 1500 grams, 1500 to 2499 grams, and greater than 2500 grams.
"start_of_prenatal_care", -- The trimester of the pregnancy in which prenatal care began.
"plurality" -- Plurality represents the number of siblings born as the result of a single pregnancy.
FROM
"delaware-gov/births-2k3z-2ap9:latest"."births"
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 delaware-gov/births-2k3z-2ap9 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 delaware-gov/births-2k3z-2ap9: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 delaware-gov/births-2k3z-2ap9Checkout 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 delaware-gov/births-2k3z-2ap9:latestThis will download all the objects for the latest tag of delaware-gov/births-2k3z-2ap9 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 delaware-gov/births-2k3z-2ap9: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 delaware-gov/births-2k3z-2ap9: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, delaware-gov/births-2k3z-2ap9 is just another Postgres schema.