Takahiro Itagaki <itagaki.takahiro@oss.ntt.co.jp> writes:
> Instead, how about excluding columns in primary keys from table data?
How will you implement "select * from mytable" ? Or even
"select * from mytable where non_primary_key = something" ?
If you can't do either of those without great expense, I think
a savings on primary-key lookups is not going to be adequate
recompense.
regards, tom lane