Re: count(*) optimization

not sure where to put this.

I run two queries:

1. select count(*) from table where indexed_column<10;
2. select * from table where indexed_column<10;

the indexed column is not clustered at all. I saw from the trace that
both query runs
through index scans on that index and takes the same amount of buffer
hits and disk read. However, shouldn't the optimizer notice that the
first query only needs to look at the indexes
and possibly reduce the amount of buffer/disk visits?

thanks

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match