#180: History table example implementation
--------------------------+-------------------------------------------------
Reporter: pramsey | Owner: pimpaa
Type: enhancement | Status: assigned
Priority: medium | Milestone: postgis 1.5.0
Component: postgis | Version:
Resolution: | Keywords:
--------------------------+-------------------------------------------------
Comment (by pramsey):
First of all, use a 'timestamp' not separate date and time columns.
Name your derived table as 'foo_history' rather than 'h_foo'. Actually
some comment on that would be useful. The 'h_' notation puts all the
history tables in one separate section of a sorted listing, while the
'_history' notation puts the history next to the table it relates to.
Which is more valuable?
Here's how history works:
On insert to table foo, insert to h_foo, with date_add = now() and
date_removed = null.
On delete from table foo, update h_foo, set date_removed = now().
On update to table foo, update current record h_foo setting date_removed =
now() **and** insert new record into h_foo, with new attributes and
date_add = now() and date_removed = null.
Because your rules don't know the attribute names at run-time, you need to
compose the rules during the history-enablement stage.
--
Ticket URL: <
http://trac.osgeo.org/postgis/ticket/180#comment:4>
PostGIS <
http://trac.osgeo.org/postgis/>
PostGIS
_______________________________________________
postgis-devel mailing list
postgis-devel@...
http://postgis.refractions.net/mailman/listinfo/postgis-devel
