4GL migration
Hello everybody! I need some help. My client is migrating from Informix 5.0 to Informix 7.x on HPUX and Informix 4GL 4.x to Informix 4GL 7.x Are there any reported issues with these migations? Could i get the steps for migration in 4GL in brief. I would be grateful. Savio Pereira Eesoft India Ltd.
ram wrote: > > Hello everybody! > > I need some help. My client is migrating from > Informix 5.0 to Informix 7.x on HPUX and > Informix 4GL 4.x to Informix 4GL 7.x > > Are there any reported issues with these migations? Could i get the steps > for migration in 4GL in brief. I would be grateful. IDS 7.xx's optimizer is MUCH smarter than OL5.xx's was this has several implications: o UPDATE STATISTICS is not enough to provide the info IDS needs. You have to run a suite of UPDATE STAT commands, as recommended in the PERFORMANCE GUIDE and implemented in several good utilities available in the IIUG Repository including my own dostats.ec in the package utils2_ak. o Most queries will run faster, however, since 5.xx was pretty dumb it tended to avoid sorting and used matching indexes instead whenever available. Not only is 7.xx smarter but it's sort code is MUCH faster so IDS 7 tends to sort if a different index can be used for filtering or joining and sometimes even prefers sequential scans. Almost always 7 produces results faster, however, interactive apps sometimes depend on the fact that 5.xx did not sort which resulted in partial results returning immediately as the index was scanned. In 7 if there is a sort no data will be returned until all rows are found and the sort complete. The new command SET OPTIMIZATION FIRST_ROWS or the {FIRST_ROWS} inline optimizer directive will direct the optimizer to favor not sorting again. o There are many new features you can take advantage of like table fragmentation, RAW tables, RESIDENT tables and indexes, detached indexes, and more. o Some simple operations will be slower though not many, and any complex queries will be MUCH faster. o Breaking jobs into multiple streams gains big time over 5.xx, IDS 7 just scales much better and takes advantage of resources better. o IDS 7 needs more memory and resources than 5 did to operate best. Art S. Kagel
We have 4GL apps running under both 4.X and 7.X for different customers, same source code, and haven't had any issues. You might run into bugs in specific versions that cause problems, but generally we've found 7.X to be pretty much backward compatible with 4.X. "ram" <r_potha@hotmail.com> wrote in message news:8mtkeq$jd72@www.informix.com... > Hello everybody! > > I need some help. My client is migrating from > Informix 5.0 to Informix 7.x on HPUX and > Informix 4GL 4.x to Informix 4GL 7.x > > Are there any reported issues with these migations? Could i get the steps > for migration in 4GL in brief. I would be grateful. > > Savio Pereira > Eesoft India Ltd. > > > >