Re: Migration issues

On Wed, 12 Aug 1998 08:23:27 +0400, Mohamed Anas <mohdanas@hotmail.com> wrote: >Hi Informix Pro's, > > > >Could anyone tell me important issues to be taken care while Online >migration from >Informix 4.1 > to >Dynamic Server 7.x Workgroup. >We have all the programs in Informix 4gl Porting the database should be simplisity itself unless may be if it's very large. I somehow doubt that there is an inplace upgrade from such an old version, but it's simple enough to do a dbexport from the old and dbimport into the new database if you have space on your disks. You do of course have to make sure you set up and tune the server correctly. This is more work than with 4.1 and does require quite a bit of study. One of the best sources for information on this is at http://www.weideneder.de, but it's unfortunately only in german. It's however good enough that it may be worth learning german just to be able to read it. Otherwise the manuals are good, posts on the issue here in c.d.i. are very valuable, books are available and there is information at http://www.iiug.org A key thing you will need and must use is the dostats utility from the util2_ak library in the software repository at the IIUG site, but there are lots of other valuable information, programs and utilities at this site. As to the 4GL programs you do have to recompile them all. It is possible to use the socalled relay module and not recompile, but you will not get the same performance. Other than this the main issue you may encounter is the new cursor naming strategy. It used to be that cursor names had to be unique in each source module. Now they have to be unique for the whole application. If you haven't allready made sure they are you should definitely take the time to do that. If you think for some reason that's to much work Informix have a solution for you where cursor names get "mangled" so there is a good chance they will be uniqly named over the application. There are two problems. One is that the mangling function sometimes doesn't quite make it so you may still get the same name on cursors in different source modules. You will have to rename these. It's hard to find out which it is however. The other is that "update ... where current of cursorname" will not work as it did before. Here you can use a special function (documented in the release notes at least) to create a mangled name for this statement. The best solution if you do not have a very large number of source modules is clearly to make sure you have unique cursor names and use -globcurs or set the appropriate environement variable when you compile. I seem to remember there might be some other small problems when recompiling your 4GL programs, but not what they where. Perhaps a year ago or so there where several posts here in c.d.i. about the issue that you may be able to find at http://www.dejanews.com Nils Myklebust NM Data AS Norway E-mail: Nils.Myklebust@nmdata.com FAQ at: http://www.iiug.org/techinfo/faq/faq_top.html (Now with ODBC info under "Third party products".)