title: Page fullness in SQL server: Is higher always better?
body: <p>So I've got a very frequently-run query on my SQL server instance that's generating a lot of wait time. On examining the Plan, I was pointed in the direction of a clustered index seek that's accountable for 93% of the cost of the whole operation.</p>
  
  <p>Examining the clustered index, I discovered that while it has 0% fragmentation listed, it has a page fullness value of only 23%. From all the research I've done, I can't really find any indication of why you would want page fullness to be low, and am anticipating that I'll want to do an index reorganize operation to set the value to something more like 90%. (This table is very frequently read from and written to, and I am led to believe too high a page fullness value creates slowdown during write operations, hence why I don't set it to something like 99% or 100%.)</p>
  
  <p>My question is this: Is there any reason I shouldn't reorganize the index and set the page fill factor to 90% or so? Any downside to doing that? I need this query, and the SQL text itself has already been optimized through Lync.</p>