Weight Track Database

Overview

The Weight Tracker database uses a JSON file to store weight entries provided by the user.

File Location

The data file is available at {root}/db/weight-tracker.json

Writing to the db

1. Before writing into the db, identify which is the best approach:

• in-memory change: load the entire file in-memory, apply the change, serialize it back
• text-based change: scan the file in text mode and apply the change as a patch

2. Isolate the atomical change you want to apply

3. Read existing data to understand which kind of operation is needed

• insert
• update
• delete

4. Apply the change with the identified approach.

ALWAYS: explain the execution plan to the user as output in the chat

Reading from the DB

1. Identify the best approach to the read request:

• in-memory change: load the entire file in-memory, evaluate logic to perform the read
• text-based change: scan the file in text mode and calculate the expected information as context

2. Perform the read of the pertinent information

3. Perform aggregations if needed

ALWAYS: explain the execution plan to the user as output in the chat

Data Structure

Always ensure the database keeps a data structure like this:

{
  "2025": {
    "11": {
      "10": 99.0,
      "12": 99.5
    }
  }
}

More info:

• the indexing of the data is: year -> month -> day
• the value of a day is a number, the database is unit agnostic
• if a new writing request targets an existing day, override the value for the day