New EXPLAIN manual page.

src/man/explain.l

+.\" This is -*-nroff-*-
+.\" XXX standard disclaimer belongs here....
+.\" $Header: /cvsroot/pgsql/src/man/Attic/explain.l,v 1.1 1996/12/29 00:58:32 momjian Exp $
+.TH EXPLAIN SQL 11/05/95 PostgreSQL PostgreSQL
+.SH NAME
+explain \(em explains statement execution details
+.SH SYNOPSIS
+.nf
+\fBexplain [with\fP \fB{cost|full}]\fR query
+.fi
+.SH DESCRIPTION
+This command outputs details about the supplied query.  The default
+output is the computed query cost.  \f2full\f1 displays a full query plan
+and costs.