CODEWITHSUNDEEP
influxdb
lovasoa
lovasoa

Reputation: 6855

How to store versioned data in an InfluxDB measurement?

I would like to use InfluxDB to store forecast data. Each forecast has an emission date, a target date, and a value. I receive several forecasts with different emission dates for the same target date.

I would like to be able to retrieve

  1. the latest forecast (the one with the latest emission date) for each target date,
  2. all the forecasts that have a certain emission date.

Upvotes: 0

Views: 240

Answers (1)

Samuel Toh
Samuel Toh

Reputation: 19228

Essentially you will be looking at having your forecast's emission_dates to be stored as part of the time field, then the target_dates as a tag and lastly storing your value in the value field.

Example:

name: forecast
time                target_dates        value
----                ------------        -----
1546516616386036270 1546000000000000000 500
1546516616390715128 1547000000000000000 600
1546516616734277026 1548000000000000000 700

The reason why I choice target_dates as tag is because tags are indexed. In case you are not aware of indexing you can find out more here.

See under "Why indexing matters: The schema case study"

This scheme design meets your requirement because;

  1. To get the latest forecast based on the emission date, you can do a SELECT * from forecast order by DESC limit 1

  2. To get all forecast of a certain emission date. Simply do SELECT * FROM "forecast" WHERE "target_dates" = '1547000000000000000'

Something worth noting here is that the target_dates above is on epoch time, format, you should be able to store any string datetime format you want.

Upvotes: 1

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