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 adoptions table in this repository, by referencing it like:
"norfolk-gov/adoptions-vj2f-2an3:latest"."adoptions"or in a full query, like:
SELECT
":id", -- Socrata column ID
"age_1_through_5", -- Includes all children in foster care who are ages 1 through 5 with the goal of adoption.
"percent_left_through_adoption", -- Percentage of all children in foster care with the goal of adoption who were discharged from foster care as the result of adoption.
"left_through_adoption", -- Includes all children in foster care with the goal of adoption who were discharged from foster care as the result of adoption.
"percent_in_placement", -- Percentage of all children in foster care with the goal of adoption whose parental rights have been terminated who are in a pre-adoptive placement.
"in_placement", -- Includes all children in foster care with the goal of adoption whose parental rights have been terminated who are in a pre-adoptive placement.
"awaiting_placement", -- Includes all children in foster care with the goal of adoption whose parental rights have been terminated and are awaiting an adoptive placement.
"percent_with_termination", -- Percentage of all children in foster care with the goal of adoption whose parental rights have been terminated.
"with_termination_of_parental", -- Includes all children in foster care with the goal of adoption whose parental rights have been terminated.
"percent_19_and_over", -- Percentage of all youth are receiving foster care services through Fostering Futures who are age 19 and over with the goal of adoption.
"percent_13_through_15", -- Percentage of children in foster care ages 13 through 15 with the goal of adoption.
"percent_10_through_12", -- Percentage of children in foster care 10 through 12 with the goal of adoption.
"age_10_through_12", -- Includes all children in foster care who are ages 10 through 12 with the goal of adoption.
"percent_6_through_9", -- Percentage of children in foster care ages 6 through 9 with the goal of adoption.
"percent_1_through_5", -- Percentage of children in foster care ages 1 through 5 with the goal of adoption.
"percent_under_1", -- Percentage of children in foster care who are under the age of 1 with the goal of adoption.
"percent_hispanic", -- Percentage of children in foster care who are identified as Hispanic with the goal of adoption.
"percent_race_unknown", -- Percentage of children in foster care whose race are unknown with the goal of adoption.
"percent_hawaiian_pacific", -- Percentage of children in foster care who are identified as Hawaiian Pacific Islander with the goal of adoption.
"american_indian_alaskan_native", -- Includes all children in foster care who are identified American Indian Alaskan Native with the goal of adoption.
"percent_white", -- Percentage of children in foster care who are identified as White with the goal of adoption.
"white", -- Includes all children in foster care who are identified as White with the goal of adoption.
"black", -- Includes all children in foster care who are identified as Black with the goal of adoption.
"percent_female", -- Percentage of all children in foster care who are identified as female with the goal of adoption.
"female", -- Includes all children in foster care who are identified as female with the goal of adoption.
"age_6_through_9", -- Includes all children in foster care who are ages 6 through 9 with the goal of adoption.
"race_unknown", -- Includes all children in foster care whose race are unknown with the goal of adoption.
"percent_asian", -- Percentage of children in foster care who are identified as Asian with the goal of adoption.
"asian", -- Includes all children in foster care who are identified as Asian with the goal of adoption.
"percent_male", -- Percentage of all children in foster care who are identified as male with the goal of adoption.
"male", -- Includes all children in foster care who are identified as male with the goal of adoption.
"percent_of_state_total", -- Percentage of children in Virginia’s foster care whose custody belongs to Norfolk Department of Human Services whose goal is adoption.
"month_and_year", -- Month and year the report covers.
"percent_awaiting_placement", -- Percentage of all children in foster care with the goal of adoption whose parental rights have been terminated and are awaiting a pre-adoptive placement.
"date_of_birth_not_entered", -- Includes all children in foster care who are do not have a birth date entered into OASIS with the goal of adoption.
"percent_16_through_18", -- Percentage of children in foster care ages 16 through 18 with the goal of adoption.
"age_16_through_18", -- Includes all children in foster care who are ages 16 through 18 with the goal of adoption.
"age_13_through_15", -- Includes all children in foster care who are ages 13 through 15 with the goal of adoption.
"percent_multi_race", -- Percentage of children in foster care who are identified as Multi-race with the goal of adoption.
"multi_race", -- Includes all children in foster care who are identified as Multi-race with the goal of adoption.
"percent_black", -- Percentage of children in foster care who are identified as Black with the goal of adoption.
"number_of_children", -- Includes all children in foster care in Norfolk with the goal of adoption.
"percent_american_indian", -- Percentage of children in foster care who are identified as American Indian Alaskan Native with the goal of adoption.
"sex_unknown", -- Includes all children in foster care whose sex is unknown with the goal of adoption.
"age_under_1", -- Includes all children in foster care who are under the age of 1 with the goal of adoption.
"hawaiian_pacific_islander", -- Includes all children in foster care who are identified Hawaiian Pacific Islander with the goal of adoption.
"hispanic", -- Includes all children in foster care who are identified Hispanic with the goal of adoption.
"percent_date_of_birth_not", -- Percentage of all children in foster care who do not have a birth date entered into OASIS with the goal of adoption.
"age_19_and_over", -- Includes all youth are receiving foster care services through Fostering Futures who are age 19 and over with the goal of adoption.
"percent_sex_unknown" -- Percentage of children in foster care whose sex is unknown with the goal of adoption.
FROM
"norfolk-gov/adoptions-vj2f-2an3:latest"."adoptions"
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 norfolk-gov/adoptions-vj2f-2an3 with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.norfolk.gov. When you querynorfolk-gov/adoptions-vj2f-2an3: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.norfolk.gov, 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 \
"norfolk-gov/adoptions-vj2f-2an3" \
--handler-options '{
"domain": "data.norfolk.gov",
"tables": {
"adoptions": "vj2f-2an3"
}
}'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, norfolk-gov/adoptions-vj2f-2an3 is just another Postgres schema.