title: PHP + MySQL - What alternatives to handle (small) time series?
body: <p>I was asked to build an expense report framework which allows users to store their expenses, one at a time, via a web form. The number of entries will never be more than 100-200 per day.</p>
  
  <p>In addition to the date and time, to be provided by the user, there must be a pre-defined set of tags (e.g.: transportation, lodging, food) to choose from for each new row of data, as well as fields for currency, amount and comments.</p>
  
  <p>Afterwards, it must be possible (or rather, easy) to fetch the entries in the db between two dates and store the data in a pandas data frame (or R data table) for posterior statistical analysis and plotting.</p>
  
  <p>I first thought about using PHP to insert the data in a mySQL database table, where the tags would be columns of booleans (True/False). The very simple web form would load by default with all tags set to False and it would be up to the user to turn the right ones to True prior to submission.</p>
  
  <p>This said, I am now wondering about the other approaches I can or should explore. I've been reading about openTSDB and InfluxDB, which are designed to handle massive amounts of data, but I am also interested in hearing from coders up-to-date with the latest technologies about other possible options.</p>
  
  <p>In short, I wish to choose a wise approach which is neither dated nor a (complex) cannon to kill a fly.</p>