"Brad Might" <[EMAIL PROTECTED]> writes: > Can someone help me break this down and figure out why the one query > takes so much longer than the other?
It looks to me like there's a correlation between filename and bucket, such that the indexscan in filename order takes much longer to run across the first 25 rows with bucket = 3 than it does to run across the first 25 with bucket = 7 or bucket = 8. It's not just a matter of there being fewer rows with bucket = 3 ... the cost differential is much larger than is explained by the count ratios. The bucket = 3 rows have to be lurking further to the back of the filename order than the others. > Here's the bucket distribution..i have clustered the index on the bucket > value. If you have an index on bucket, it's not doing you any good here anyway, since you wrote the constraint as a crosstype operator ("3" is int4 not int8). It might help to explicitly cast the constant to int8. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings