Re: TOAST usage setting

Gregory Stark wrote:
> "Bruce Momjian"  writes:
> 
> > Gregory Stark wrote:
> >
> >> Is your database initialized with C locale? If so then length(text) is
> >> optimized to not have to detoast:
> >> 
> >> 	if (pg_database_encoding_max_length() == 1)
> >> 		PG_RETURN_INT32(toast_raw_datum_size(str) - VARHDRSZ);
> >
> > Wow, we optimized length().  OK, will run the test with
> > substring(t,1,1).
> 
> No, we did substring() too :)

Uh, I looked at text_substring(), and while there is an optimization to
do character counting for encoding length == 1, it is still accessing
the data.

--  Bruce Momjian            http://momjian.us EnterpriseDB                               http://www.enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +