> SELECT SUM(pg_relation_size(pg_class.oid)) > FROM pg_class ;
Perhaps you want pg_total_relation_size()?
-Kevin
The number returned when using pg_total_relation size makes more sense: 346GB. However it looked like pg_class has toast and indexes listed individually, so I assumed that using pg_total_relation_size would count values twice, because the total relation size of table would include toast and indexes, and then they would get counted again when I ran pg_total_relation_size on the toast and indexes themselves. Is that an incorrect assumption on my part?