On 4/5/11 12:24 PM, Ben Pfaff wrote: > + /* If this is a write-only column and the datum being written is the same > + * as the one already there, just skip the update entirely. This is > worth > + * optimizing because we have a lot of columns that get periodically > + * refreshed into the database but don't actually change that often. > + * > + * We don't do this for read/write columns because that would break > + * atomicity of transactions--some other client might have written a > + * different value in that column since we read it. */
What prevents another client from writing a different value since we last read the row? _______________________________________________ dev mailing list [email protected] http://openvswitch.org/mailman/listinfo/dev
