title: ios comparing memcache and core data
body: <p>Currently in order to limit the number of mysql requests, each user has a folder with multiple empty files corresponding to updates made in the database.  The last accessed date of a file is compared to a date stored in core data.  Only if the last accessed date is after the date in core data does the db get queried.  </p>
  
  <p>For example, if userA sends a friend request to userB, this is written to the db and the file /userB/friend is touched to update the date last assessed to the current date.  Now when userB gets to a script that queries the db for his friend requests, it first checks if the last accessed date of /userB/friend is after the date in core data and only runs it if this is the case.  The new last accessed date along with the data from the query are then stored in core data.</p>
  
  <p>My question is, are there any foreseeable issues with this method I am currently using and is it any better or worse then using memcached to avoid querying the same data over and over again? </p>
  
  <p>I also realize the title of this post is a little mislabeled but I don't know if a name for the method I am using exists.</p>