I have had frequent complaints from folks on my biggest board regarding the search results. It seems that for many users page two (and beyond) was not available. Frankly, I was stumped. I worked with some users to verify that they have cookie settings that work and to ensure that their search session was not timing out. I checked (and tweaked) the code that clears out old search sessions to make sure their search results were not being truncated too early. The main thing was, I was never able to reproduce the error. That makes it very frustrating when trying to debug and fix an issue.
It turns out that the root cause had nothing to do with a cookie or session problem. The cause was that these users were running searches that returned a huge number of posts or topics. I figured that out by looking at the MySQL query logs and noted something specific to this issue.
Why should the number of resulting posts matter if I am only trying to go to page 2? Shouldn’t it be an issue only if I am trying to view page 800 instead?