m4_comment([$Id: db.so,v 11.10 2006/04/24 17:26:34 bostic Exp $])

m4_ref_title(Upgrading m4_db Applications,
    Release 3.0: the DB structure,, upgrade.3.0/xa, upgrade.3.0/dbinfo)

m4_p([dnl
The m4_ref(Db) structure is now opaque for applications in the m4_db 3.0
release.  Accesses to any fields within that structure by the application
should be replaced with method calls.  The following example illustrates
this using the historic type structure field.  In the m4_db 2.X releases,
applications could find the type of an underlying database using code
similar to the following:])

m4_indent([dnl
DB *db;
DB_TYPE type;
m4_blank
	type = db-__GT__type;])

m4_p([dnl
in the m4_db 3.X releases, this should be done using the
m4_ref(dbh_get_type) method, as follows:])

m4_indent([dnl
DB *db;
DB_TYPE type;
m4_blank
	type = db-__GT__get_type(db);])

m4_p([dnl
The following table lists the m4_ref(Db) fields previously used by
applications and the methods that should now be used to get or set them.])

m4_table_begin(, _center)
m4_table_header(m4_ref(Db) field, m4_db 3.X method)
m4_table_element(byteswapped, m4_ref(dbh_get_byteswapped))
m4_table_element(db_errcall, m4_ref(dbh_set_errcall))
m4_table_element(db_errfile, m4_ref(dbh_set_errfile))
m4_table_element(db_errpfx, m4_ref(dbh_set_errpfx))
m4_table_element(db_paniccall, DB-__GT__set_paniccall)
m4_table_element(type, m4_ref(dbh_get_type))
m4_table_end

m4_page_footer