Log Message:
-----------
Update manual's introduction to indexes to reflect 8.1 changes; in
particular the addition of bitmap scans and the relaxation of rules
about when multicolumn indexes can be used. Also some minor editorial
work in other parts of the chapter.
Modified Files:
--------------
pgsql/doc/src/sgml:
indices.sgml (r1.51 -> r1.52)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/indices.sgml.diff?r1=1.51&r2=1.52)