"Sergey Moroz" <smo@xxxxxxxx> writes: > I tested performance of my query with limit clause inside plpgsql procedure. > 2 slightly different situations: > 1. Sql with limit clause and literal variable (for example 'select field1 > from table1 limit 100') > 2. The same sql with limit clause and pgplsql variable (for example 'select > field1 from table1 limit vilimit'). vilimit defined in declare section. > At first I compared execution plans. they were absolutely equal! > But in fact first procedure was 10 times!!!! faster then the second! Exactly what did you do to conclude that the execution plans were the same? I would not expect the planner to choose the same plan in these two cases, at least not if 100 is just a small fraction of the total estimated query output. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly