usaid-gov/baseline-study-of-food-for-peace-title-ii-tur3-c2we

Query the Data Delivery Network

Query the DDN

The 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 procotol. 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 baseline_study_of_food_for_peace_title_ii table in this repository, by referencing it like:

"usaid-gov/baseline-study-of-food-for-peace-title-ii-tur3-c2we:latest"."baseline_study_of_food_for_peace_title_ii"

or in a full query, like:

SELECT 
    ":id", -- Socrata column ID
    "dis", -- DISTRICT NUMBER
    "b20a", -- B20A Highest level completed during the 2012 school year
    "b12", -- B12 What is current marital status
    "female_adult", -- Household has at least one female 18 or older
    "hh", -- HOUSEHOLD NUMBER
    "child", -- Household has at least one child under 18
    "b03", -- B03 Relationship to head of household
    "education_level", -- Education level
    "b13", -- B13 Is natural mother alive
    "b07", -- B07 IS THIS A CHILD UNDER 6 YEARS
    "b14", -- B14 Does natural mother usually live in this household
    "id",
    "member_id", -- Household member ID for merging with other modules
    "vn", -- VILLAGE NUMBER
    "b18b", -- B18B Highest grade completed at that level
    "b08", -- B08 LINE NUMBER OF PRIMARY CAREGIVER FOR CHILD
    "male_adult", -- Household has at least one male 18 or older
    "b06", -- B06 Is this person responsible for food preparation
    "b17", -- B17 Ever attended school
    "b05_bin", -- Age Binned
    "cluster", -- Cluster
    "b18a", -- B18A Highest level of school attended
    "b19", -- B19 Attend school at any time during the 2012 school year
    "b16", -- B16 Does natural father usually live in this household
    "b15", -- B15 Is natural father alive
    "b11", -- B11 IS THIS PERSON A FARMER
    "b04", -- B04 Sex
    "strata", -- Strata
    "b01", -- B01 LINE NUMBER OF HOUSEHOLD MEMBER
    "b05", -- B05 Age
    "b20b", -- B20B Highest grade completed during the 2012 school year
    "b10", -- B10 IS THIS THE HEAD OF HOUSEHOLD OR RESPONSIBLE ADULT
    "b09", -- B09 IS THIS A WOMAN 15 49 YEARS
    "hhwt", -- Household Weight
    "pvo" -- PVO
FROM
    "usaid-gov/baseline-study-of-food-for-peace-title-ii-tur3-c2we:latest"."baseline_study_of_food_for_peace_title_ii"
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 usaid-gov/baseline-study-of-food-for-peace-title-ii-tur3-c2we with SQL in under 60 seconds.

This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.usaid.gov. When you queryusaid-gov/baseline-study-of-food-for-peace-title-ii-tur3-c2we: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

Install Splitgraph Locally
bash -c "$(curl -sL https://github.com/splitgraph/splitgraph/releases/latest/download/install.sh)"
 

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.usaid.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 \
  "usaid-gov/baseline-study-of-food-for-peace-title-ii-tur3-c2we" \
  --handler-options '{
    "domain": "data.usaid.gov",
    "tables": {
        "baseline_study_of_food_for_peace_title_ii": "tur3-c2we"
    }
}'

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, usaid-gov/baseline-study-of-food-for-peace-title-ii-tur3-c2we is just another Postgres schema.

Related Documentation: