Durability and performance

June 23rd, 2010  |  Tags:

Wolf Rentzsch shares an amusing anecdote about “high-performance” database systems whose developers claim to achieve high performance by eschewing sync calls. Recall that the sync system call is the one that ensures that the bits that you’ve just written to disk actually made it to the disk. It essentially trades the performance afforded by multiple layers of caching in modern disks for the reliability of knowing that no data is still in-flight when the call returns.

Of course, the no-sync approach doesn’t go nearly far enough; I bet these database developers could improve performance still more by avoiding writing anything to disk in the first place.