by Silver Springs... >> Mon, 1 Feb 1999 20:34:54 GMT
Hi
Map files are those wonderful beasties that our applications data resides in and usually live in your SYSTEM or DEPLOY directory and have a .DAT extension.
One application may have a number of map files setup for it -- in fact it's a good idea to group your classes into mulitple map files as this can speed up Reorg's at live run-time sites when updating.
However, with JADE 4.0.x you couldn't change the name of map files once they were created and it's quite easy to have map files named inappropriately as people often create a new project schema by using an existing one for another project as a base --- and lo and behold the new application then uses the same map file.
JADE 4.1.10 now allows you to change the name and path of your Map files in the Map Browser.
Ah ha -- you may think ... this solves the problem and now I can change my applications map files to more meaningful names ? Yes and no !
Yes -- and its useful whilst you are developing the application and there are no deployed installations of it and no other schema uses the same iles --- no otherwise !
If the map file is used by another schema and you rename it (say, from A to B) -- then this automatically renames the physical .DAT file in the SYSTEM directory from A.DAT to B.DAT. It does nothing to the other schema that when set in the schema browser will still want to look at A.DAT and won't be able to find it. It will throw a System Exception and deny access to that schema !
Also, if you have deployed run-time version/s of the application -- then sure you can change the map file names in your development environment --- but when you come to upgrade the run-time installation by applying the new schema .SCM/.DDB files with JADE Loader then grief will ensue. The upgrade process will NOT change the map file names in the deployed installation for you and there is no real way to do this -- so you've got to stick with the original map file names if you want to save data etc at the run-time installation !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
You may wonder in these circumstances why did they put the facility to rename map files into 4.1.x without providing for this during the upgrade process at run-time installations, or dealing with the problem of more than one schema accessing the same map file ?
I have been told that the facility may be removed in a future release because of these kind of problems.
Lordy.....
Alan J.Thomson
ph...Auckland 09-366-1463
http://home.clear.net.nz/pages/athomson