C-ISAM To Informix Migration
Hi Informants.. We use C-ISAM database in our application. C-ISAM is a flat file database software manufactured by Informix. Eventually we are now migrating from C-ISAM to Informix. In C-ISAM tables are maintained as files. They are typedefs as 'C' structures. So the tables can hold anything that a 'C' structure can hold. We have a table which contains union. Apparently this was used to store, table with in table, for faster access. As for my question, as we are now moving to Informix, can i replace the unions, with JOIN in the application code? Is there any migration guide available for moving from c-isam to informix. Thanks Anand Sent via Deja.com http://www.deja.com/ Share what you know. Learn what you don't.
anandpa@my-deja.com wrote: > > Hi Informants.. > > We use C-ISAM database in our application. > C-ISAM is a flat file database software > manufactured by Informix. > > Eventually we are now migrating from C-ISAM to > Informix. > In C-ISAM tables are maintained as files. They are > typedefs as 'C' structures. So the tables can hold anything > that a 'C' structure can hold. > We have a table which contains union. Apparently > this was used to store, table with in table, > for faster access. > As for my question, as we are now moving > to Informix, can i replace the unions, with JOIN in > the application code? Is there any migration guide available > for moving from c-isam to informix. Unless you go to IDS/UDO or wait for IDS.2000 next month so you can write a UDR (User Defined Record) type you will have to implement that union as a set of tables, one for each type and either implement fetching using a separate query to the appropriate sub-type record or fetch from all of the possible sub-types always using outer joins. The structure you describe lends itself far better to an Object or Object Relational database like UDO or IDS.2000 than to a purely Relational database like baseline IDS. There has been much written on the subject of managing these structures in RDBMSs, but I cannot remember any specific sources right now. Art S. Kagel