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 bho_mh_readmission_20102014 table in this repository, by referencing it like:
"ny-gov/bho-mh-readmission-20102014-inhb-jgj2:latest"."bho_mh_readmission_20102014"or in a full query, like:
SELECT
":id", -- Socrata column ID
"indicator_domain_group", -- This is the domain group that the BHO Performance Indicator belongs to. For this dataset, the domain group is “MH Readmissions”
"year_to_date_denominator", -- Value of the bottom of the "Rate" calculation for the Age Group, OMH Region, Performance Metric and Year to Date being examined. For example, for a given metric in Q4 of 2012, the Denominator is the number of Discharges from inpatient psychiatric units at general hospitals (Article 28), private psychiatric hospitals (Article 31), and state operated psychiatric hospitals (SPCs) within the specified time frame and region of the metric (30 or 90 days after discharge, “same” or “any” region) during Quarters 1, 2, 3 and 4 of 2012.
"year_to_date_numerator", -- Value of the "top" of the "Rate" calculation for the year to date as of the Quarter that is being examined. For example, for a given metric in Q4 of 2012, the Numerator is the number of Readmissions within the specified time frame and region of the metric (30 or 90 days after discharge, “same” or “any” region) during Quarters 1, 2, 3 and 4 of 2012.
"quarter", -- Quarter for which the metric is calculated: Q1, Q2, Q3, Q4 or some combination of one or more quarters
"omh_region", -- Name of the OMH Region for which the Indicator is calculated
"row_created_date_time", -- Date and Time when data was generated (e.g. “12/19/2014 09:45:21”)
"age_group", -- Standardized Age Groups; either “Adult” or “Children”.
"numerator", -- Value of the "top" of the "Rate" calculation for the Age Group, OMH Region, Performance Metric and Quarter that is being examined. For more detailed descriptions of the Numerators for the MH Readmission dataset, see the “Detailed Metric Descriptions” table in the data dictionary attached to this dataset.
"rate", -- For the Age Group, OMH Region, Performance Metric and Quarter being examined, this is the rate of the metric as calculated by dividing the Numerator by the Denominator.
"year", -- 4 Digit year for which the metric is calculated
"year_to_date_rate", -- For the Performance Metric and the Quarter being examined, this is the rate of the metric as calculated by dividing the Year to Date Numerator by the Year to Date Denominator.
"metric_id", -- Numeric Code that uniquely identifies the Metric
"denominator", -- Value of "bottom" of the calculation for the Age Group, OMH Region, Performance Metric and Quarter that is being examined. For the MH Readmissions dataset, the Denominator includes discharges from inpatient psychiatric units at general hospitals (Article 28), private psychiatric hospitals (Article 31), and state operated psychiatric hospitals (SPCs) that are identified from paid fee-for-service Medicaid claims. Individuals who meet any of the following criteria are excluded: Ineligible for Medicaid in any of the 90 days post discharge; Medicare-eligible.
"description_of_metric" -- Short description of the BHO Performance Metric. For this MH Readmission dataset, there are three possible metrics: 1. Rate of Readmission to Inpatient MH Treatment within 30 Days (Readmission in Any Geographic Region) 2. Rate of Readmission to Inpatient MH Treatment within 30 Days (Readmission in the Same Geographic Region) 3. Rate of Readmission to Inpatient MH Treatment within 90 Days (Readmission in Any Geographic Region) For more detail, see the “Detailed Metric Definitions” table in the data dictionary attached to this dataset.
FROM
"ny-gov/bho-mh-readmission-20102014-inhb-jgj2:latest"."bho_mh_readmission_20102014"
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 ny-gov/bho-mh-readmission-20102014-inhb-jgj2 with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.ny.gov. When you queryny-gov/bho-mh-readmission-20102014-inhb-jgj2: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.ny.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 \
"ny-gov/bho-mh-readmission-20102014-inhb-jgj2" \
--handler-options '{
"domain": "data.ny.gov",
"tables": {
"bho_mh_readmission_20102014": "inhb-jgj2"
}
}'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, ny-gov/bho-mh-readmission-20102014-inhb-jgj2 is just another Postgres schema.