Faster or Lazier Pagination - interesting approach, simply not to determine the amount of sentences, but instead to assume a number of pages and update this when accessing later pages. A bit similar to some websites that only offer a section of the page list as navigation - for this you don't need to know how many pages there really are. Google also cheats by limiting the number of pages to a maximum. For large amounts of data with slow count(*) certainly very useful and possibly you could also combine this with cached maximum page numbers for different queries, so that the next time the assumption about the amount is already more precise.