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 city_senior_center_interval_energy_data table in this repository, by referencing it like:
"cambridgema-gov/city-senior-center-interval-energy-data-uuej-6t9x:latest"."city_senior_center_interval_energy_data"or in a full query, like:
SELECT
":id", -- Socrata column ID
"time_15_10",
"time_15_15",
"time_15_20",
"time_15_45",
"time_15_55",
"time_16_00",
"time_16_10",
"time_16_15",
"time_16_20",
"time_16_30",
"time_16_35",
"time_16_55",
"time_17_00",
"time_17_05",
"time_17_10",
"time_17_15",
"time_17_25",
"time_17_35",
"time_17_40",
"time_17_45",
"time_17_50",
"time_18_00",
"time_18_05",
"time_18_10",
"time_18_15",
"time_18_20",
"time_18_35",
"time_18_40",
"time_18_45",
"time_18_55",
"time_19_00",
"time_19_05",
"time_19_10",
"time_19_15",
"time_19_20",
"time_19_25",
"time_19_30",
"time_19_35",
"time_19_40",
"time_19_45",
"time_19_55",
"time_20_10",
"time_20_20",
"time_20_25",
"time_20_30",
"time_20_35",
"time_20_40",
"time_20_45",
"time_20_50",
"time_20_55",
"time_21_00",
"time_21_05",
"time_21_10",
"time_21_15",
"time_21_20",
"time_15_25",
"time_23_40", -- Data is measured in 5-minute time intervals
"time_23_25", -- Data is measured in 5-minute time intervals
"time_23_15",
"time_23_10",
"time_23_05",
"time_23_00",
"time_22_55",
"time_22_45",
"time_22_40",
"time_22_35",
"time_22_30",
"time_22_25",
"time_22_20",
"time_22_15",
"time_22_05",
"time_22_00",
"time_21_55",
"time_21_50",
"time_21_45",
"time_21_35",
"time_21_30",
"time_11_10",
"time_11_15",
"time_11_25",
"time_11_35",
"time_11_40",
"time_11_50",
"time_11_55",
"time_12_00",
"time_12_15",
"time_12_20",
"time_12_25",
"time_12_30",
"time_12_40",
"time_12_45",
"time_12_50",
"time_13_05",
"time_13_10",
"time_13_20",
"time_13_25",
"time_13_30",
"time_13_40",
"time_13_45",
"time_13_55",
"time_14_00",
"time_14_05",
"time_14_10",
"time_14_15",
"time_14_20",
"time_14_30",
"time_14_35",
"time_14_40",
"time_14_45",
"time_14_50",
"time_15_30",
"time_16_40",
"time_16_25",
"time_12_10",
"time_12_35",
"time_13_35",
"time_20_05",
"time_21_25",
"time_21_40",
"time_17_20",
"time_17_30",
"time_23_35", -- Data is measured in 5-minute time intervals
"time_22_50",
"time_22_10",
"time_23_30", -- Data is measured in 5-minute time intervals
"time_6_35", -- Data is measured in 5-minute time intervals
"time_4_30", -- Data is measured in 5-minute time intervals
"time_4_00", -- Data is measured in 5-minute time intervals
"time_15_35",
"time_10_30",
"time_10_55",
"time_11_30",
"time_11_45",
"time_7_25",
"time_14_55",
"time_16_50",
"time_15_00",
"time_16_45",
"time_16_05",
"time_12_55",
"time_13_00",
"time_20_15",
"time_20_00",
"time_19_50",
"time_17_55",
"time_18_50",
"time_18_30",
"time_2_45", -- Data is measured in 5-minute time intervals
"time_0_35", -- Data is measured in 5-minute time intervals
"time_1_00", -- Data is measured in 5-minute time intervals
"time_1_30", -- Data is measured in 5-minute time intervals
"time_0_25", -- Data is measured in 5-minute time intervals
"time_4_45", -- Data is measured in 5-minute time intervals
"time_1_20", -- Data is measured in 5-minute time intervals
"time_5_20", -- Data is measured in 5-minute time intervals
"time_1_25", -- Data is measured in 5-minute time intervals
"time_5_10", -- Data is measured in 5-minute time intervals
"time_3_50", -- Data is measured in 5-minute time intervals
"time_4_25", -- Data is measured in 5-minute time intervals
"time_24_00", -- Data is measured in 5-minute time intervals
"time_2_55", -- Data is measured in 5-minute time intervals
"time_3_40", -- Data is measured in 5-minute time intervals
"time_1_40", -- Data is measured in 5-minute time intervals
"time_5_00", -- Data is measured in 5-minute time intervals
"time_1_15", -- Data is measured in 5-minute time intervals
"time_23_55", -- Data is measured in 5-minute time intervals
"time_3_05", -- Data is measured in 5-minute time intervals
"time_6_50", -- Data is measured in 5-minute time intervals
"time_0_05", -- Data is measured in 5-minute time intervals
"time_6_10", -- Data is measured in 5-minute time intervals
"time_0_40", -- Data is measured in 5-minute time intervals
"time_0_30", -- Data is measured in 5-minute time intervals
"time_5_55", -- Data is measured in 5-minute time intervals
"time_6_00", -- Data is measured in 5-minute time intervals
"time_6_15", -- Data is measured in 5-minute time intervals
"time_6_20", -- Data is measured in 5-minute time intervals
"time_6_30", -- Data is measured in 5-minute time intervals
"time_6_40", -- Data is measured in 5-minute time intervals
"time_6_45", -- Data is measured in 5-minute time intervals
"time_6_55", -- Data is measured in 5-minute time intervals
"time_7_00", -- Data is measured in 5-minute time intervals
"time_7_15", -- Data is measured in 5-minute time intervals
"time_7_20",
"time_7_30",
"time_7_35",
"time_7_40",
"time_7_45",
"time_7_50",
"time_7_55",
"time_8_00",
"time_8_10",
"time_8_15",
"time_8_20",
"time_8_25",
"time_8_30",
"time_8_35",
"time_8_40",
"time_8_45",
"time_8_50",
"time_8_55",
"time_9_00",
"time_9_05",
"time_9_10",
"time_9_15",
"time_9_20",
"time_9_25",
"time_9_30",
"time_9_35",
"time_9_45",
"time_9_50",
"time_9_55",
"time_10_00",
"time_10_05",
"time_10_10",
"time_10_15",
"time_10_20",
"time_10_25",
"time_10_35",
"time_10_40",
"time_10_45",
"time_10_50",
"time_11_00",
"time_11_05",
"time_4_20", -- Data is measured in 5-minute time intervals
"time_2_05", -- Data is measured in 5-minute time intervals
"account", -- Utility Account Number
"time_0_45", -- Data is measured in 5-minute time intervals
"time_0_50", -- Data is measured in 5-minute time intervals
"time_1_55", -- Data is measured in 5-minute time intervals
"time_2_15", -- Data is measured in 5-minute time intervals
"time_3_15", -- Data is measured in 5-minute time intervals
"time_5_05", -- Data is measured in 5-minute time intervals
"time_5_15", -- Data is measured in 5-minute time intervals
"time_6_05", -- Data is measured in 5-minute time intervals
"time_6_25", -- Data is measured in 5-minute time intervals
"time_5_40", -- Data is measured in 5-minute time intervals
"measure", -- Electricity Use or Electricity Demand. Electricity use is the amount of electricity that has been consumed over a certain period of time. Electricity demand is the maximum amount of electrical energy that is being consumed at a given time.
"time_15_05",
"time_8_05",
"time_9_40",
"time_3_30", -- Data is measured in 5-minute time intervals
"time_5_45", -- Data is measured in 5-minute time intervals
"time_0_20", -- Data is measured in 5-minute time intervals
"units", -- Units measuring electricity use or electricity demand. Electricity use is measured in kilowatt hours (kWh). Electricity demand is measured in kilowatts (kW). Additionally, this dataset contains measurements for Power Factor and Reactive Power. Power Factor is the ratio of the real power that is flowing to the load and the apparent power that is supplied to the circuit. Reactive Power occurs in alternating current circuits when there is a phase difference between voltage and current. It is measured in kVAR for demand and kVARh for use.
"time_23_20",
"time_18_25",
"time_13_50",
"time_14_25",
"time_12_05",
"time_13_15",
"time_15_40",
"time_15_50",
"time_7_05", -- Data is measured in 5-minute time intervals
"time_7_10", -- Data is measured in 5-minute time intervals
"time_11_20",
"time_3_45", -- Data is measured in 5-minute time intervals
"time_3_55", -- Data is measured in 5-minute time intervals
"time_4_55", -- Data is measured in 5-minute time intervals
"time_2_35", -- Data is measured in 5-minute time intervals
"date", -- Date of measurment
"channel", -- Information that is available from a Utility Meter. For Electricity Use: Power Factor, Reactive Power and Electricity Use. For Electricity Demand: Demand, Power Factor and Reactive Power
"time_0_10", -- Data is measured in 5-minute time intervals
"time_0_15", -- Data is measured in 5-minute time intervals
"time_0_55", -- Data is measured in 5-minute time intervals
"time_1_05", -- Data is measured in 5-minute time intervals
"time_1_10", -- Data is measured in 5-minute time intervals
"time_1_35", -- Data is measured in 5-minute time intervals
"time_1_45", -- Data is measured in 5-minute time intervals
"time_1_50", -- Data is measured in 5-minute time intervals
"time_2_00", -- Data is measured in 5-minute time intervals
"time_2_10", -- Data is measured in 5-minute time intervals
"time_2_20", -- Data is measured in 5-minute time intervals
"time_2_25", -- Data is measured in 5-minute time intervals
"time_2_30", -- Data is measured in 5-minute time intervals
"time_2_40", -- Data is measured in 5-minute time intervals
"time_2_50", -- Data is measured in 5-minute time intervals
"time_3_00", -- Data is measured in 5-minute time intervals
"time_3_10", -- Data is measured in 5-minute time intervals
"time_3_20", -- Data is measured in 5-minute time intervals
"time_3_25", -- Data is measured in 5-minute time intervals
"time_3_35", -- Data is measured in 5-minute time intervals
"time_4_05", -- Data is measured in 5-minute time intervals
"time_4_10", -- Data is measured in 5-minute time intervals
"time_4_15", -- Data is measured in 5-minute time intervals
"time_4_35", -- Data is measured in 5-minute time intervals
"time_4_40", -- Data is measured in 5-minute time intervals
"time_4_50", -- Data is measured in 5-minute time intervals
"time_5_25", -- Data is measured in 5-minute time intervals
"time_5_30", -- Data is measured in 5-minute time intervals
"time_5_35", -- Data is measured in 5-minute time intervals
"time_5_50", -- Data is measured in 5-minute time intervals
"time_23_50", -- Data is measured in 5-minute time intervals
"time_23_45" -- Data is measured in 5-minute time intervals
FROM
"cambridgema-gov/city-senior-center-interval-energy-data-uuej-6t9x:latest"."city_senior_center_interval_energy_data"
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 cambridgema-gov/city-senior-center-interval-energy-data-uuej-6t9x with SQL in under 60 seconds.
This repository is an "external" repository. That means it's hosted elsewhere, in this case at data.cambridgema.gov. When you querycambridgema-gov/city-senior-center-interval-energy-data-uuej-6t9x: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.cambridgema.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 \
"cambridgema-gov/city-senior-center-interval-energy-data-uuej-6t9x" \
--handler-options '{
"domain": "data.cambridgema.gov",
"tables": {
"city_senior_center_interval_energy_data": "uuej-6t9x"
}
}'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, cambridgema-gov/city-senior-center-interval-energy-data-uuej-6t9x is just another Postgres schema.