Some questions thinking about HTML5 Client-Side Storage:

  1. Just how much data in Local Storage is recognized as an excessive amount of?
  2. It is possible to limit around the size?
  3. Since its saved on files does it at all work around the browsers speed?
  4. Why would you use Database storage? could it be indexed? Why don't you use LocalStorage where secret is the index (if unique) from the record, and also the value may be the record JSON stringified?

EDIT
Only a follow-up towards the Answer, following the WebDatabase project was dropped, all browser are proceeding to implement the potential standard " IndexedDB "

Take a look other Question. HTML5 localStorage restrictions and limits

  1. It is dependent in your application.
  2. 5 megabytes may be the max size
  3. No impact.
  4. Database storage is deprecated, so it won't receive more updates. Current browsers support it, yet their implementation might not be standard. So it's not recommended for doing things.