This patch implements expressing GUC variables as percents in postgresql.conf.
autovacuum_vacuum_scale_factor = 20% # percent of table size before vacuum
autovacuum_analyze_scale_factor = 10% # percent of table size before analyze
As you can see the postgresql.conf file and the documentation read more naturally. I added a regression test to guc.sql. The sql interface also accepts both numeric and percent forms although the percent form must be quoted because '%' is an operator.
show cursor_tuple_fraction; --> 10%
set cursor_tuple_fraction = .15; --> 15%
set cursor_tuple_fraction = '33%'; --> 33%
I tagged four configuration variables to display as percents.
The attached patch applies cleanly against master and passes all regression tests including two new tests in guc.sql.
