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 state_agency_amazon_spend_fiscal_year_19
table in this repository, by referencing it like:
"wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv:latest"."state_agency_amazon_spend_fiscal_year_19"
or in a full query, like:
SELECT
":id", -- Socrata column ID
"order_date", -- Date the order was placed.
"discount_program", -- Negotiated Pricing or Quantity Discounts.
"agency_name", -- Name of agency that placed order.
"asin", -- Amazon Standard Identification Number for products.
"brand", -- Item Brand as provided by the vendor or seller.
"brand_code", -- Brand code as provided by the vendor or seller.
"item_model_number", -- Generic model number for the item. This information is provided by the vendor or seller.
"item_net_total", -- Total charged for the item. Including tax, discounts, shipping and handling, and item price.
"item_promotion", -- Total discounts or promotions applied to a line item. Includes all discount components (discount on price, shipping, gift wrapping, other fees, etc.). Excludes tax.
"item_quantity", -- Quantity of a line item.
"item_shipping_handling", -- Principal amounts for the shipping and handling for each item. Excludes the corresponding tax and discount amounts.
"item_subtotal", -- Total principal amount you paid for individual items in the order. Excludes tax, promotions, discounts, and shipping and handling.
"item_tax", -- Total tax charged on item.
"listed_ppu", -- Listed Price Per Unit on Amazon Business.
"manufacturer", -- Name of the manufacturer as provided by the vendor or seller.
"part_number", -- Manufacturer part number as provided by the vendor or seller.
"payment_amount", -- Amount charged for a particular transaction.
"payment_date", -- Date when payment transaction was made.
"pricing_discount_applied", -- Amount (in dollars) discounted as part of a pricing program.
"pricing_discount_applied_1", -- Percentage discounted as part of a pricing program.
"product_category", -- Category of the product according to Amazon terminology.
"product_condition", -- Condition of the item purchased (new, used, used good, etc.).
"purchase_ppu", -- Purchased Price Per Unit.
"seller_name", -- Name of the seller on Amazon.com.
"shipment_date", -- Date when the item was shipped.
"title", -- Product title on Amazon.
"unspsc" -- United Nations Standard Products and Services Code
FROM
"wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv:latest"."state_agency_amazon_spend_fiscal_year_19"
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 wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv
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; sgr
can 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 clone
and sgr checkout
.
Cloning Data
Because wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv: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 wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv
Checkout 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 wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv:latest
This will download all the objects for the latest
tag of wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv
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 wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv: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 wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv:latest
This 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, wa-gov/state-agency-amazon-spend-fiscal-year-19-msv2-8gcv
is just another Postgres schema.