Hi, Nils, Nis Jorgensen wrote: > It will probably be quite common for the number to depend on the number > of rows in other tables. Even if this is fairly constant within one db > (some assumption), it is likely to be different in others using the same > function definition. Perhaps a better solution would be to cache the > result of the estimator function. Sophisticated estimator functions are free to use the pg_statistics views for their row count estimation. HTH, Markus -- Markus Schaber | Logical Tracking&Tracing International AG Dipl. Inf. | Software Development GIS Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org