ntile() is one of those functions that just never seems to work the way users expect regardless of the RDBMS. I don't know if the spec's definition was just po

ntile() is one of those functions that just never seems to work the way users expect regardless of the RDBMS. I don't know if the spec's definition was just poorly thought out or what, but it's often flaky, poorly performing, or both in many RDBMSs. In PostgreSQL, you should generally use cume_dist(), percentile_cont() and percentile_disc(). Most later releases of other RDBMS have similar window functions that work more like users expect. I'm not certain what's up, but it's definitely led me to believe that ntile() was just poorly thought out at the spec level.