I don't know if this is a bug, or a surprising feature, or just a misunderstanding. If I specify an explicit collation which happens to be the same as the default collation, it is not recognized as being the same as the default. select version(); version --------------------------------------------------------------------------------------------------------------- PostgreSQL 9.4.5 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16), 64-bit (But also in at least 9.5rc1 and 9.6dev) create database test2 encoding='utf8' lc_collate='en_US.utf8' template=template0; \c test2 create table foo as select generate_series::text as bar from generate_series(1,100000); create index on foo (bar ); cluster foo USING foo_bar_idx ; set enable_sort TO off; explain select * from foo order by bar; <walks the index> explain select * from foo order by bar collate "en_US.utf8"; <does the sort> Am I the only one surprised by this? Cheers, Jeff -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general