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 iowa_child_abuse_occurrences_by_year_county_and table in this repository, by referencing it like:
"mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias:latest"."iowa_child_abuse_occurrences_by_year_county_and"or in a full query, like:
SELECT
":id", -- Socrata column ID
"dhs_service_area", -- The DHS Service area associated with the county. Service area represents the name of the service area at time of the assessment.
"geocoded_column", -- Primary latitude and longitude in decimal degrees that create the primary point for the county as provided by U.S. Geological Survey, 19810501, U.S. Geographic Names Information System (GNIS): U.S. Geological Survey, Reston, VA. The primary point is generally at or near the geographic center of the county.
"judicial_district", -- The Judicial District associated with the county.
"abuse_type", -- Types of maltreatment that can be reported for each child included for a child welfare assessment. There are seven types that are more commonly used, the others are included in "other". On July 1, 2009, the type "Cohabitation w/ a Registered Sex Offender" was replaced with "Allows Access by Registered Sex Offender" due to a change in statute.
"occurances", -- Number of occurrences reported during child welfare assessments with confirmed or founded findings. Each child may be confirmed of multiple types of abuse on a single assessment, and may have multiple assessments.
"county_name", -- The child's county of residence at time of the child welfare assessment with occurrence of child abuse.
"fips_county_code", -- A federal information processing series five-digit code for the identification of counties and county equivalents of the United States and its insular and associated areas, for the purpose of information interchange among data processing systems. (INCITS 31-2009). The code is associated with the listed county.
"year", -- The calendar year when child welfare assessment was conducted.
":@computed_region_3r5t_5243",
":@computed_region_wnea_7qqw",
":@computed_region_i9mz_6gmt",
":@computed_region_e7ym_nrbf"
FROM
"mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias:latest"."iowa_child_abuse_occurrences_by_year_county_and"
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 mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias 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 mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias: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 mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fiasCheckout 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 mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias:latestThis will download all the objects for the latest tag of mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias 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 mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias: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 mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias: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, mydata-iowa-gov/iowa-child-abuse-occurrences-by-year-county-and-mh9d-fias is just another Postgres schema.