Re: Loading Data

From: jrw3319@gis.net (John Welch) > > I'm new to Informix and RDBMS so forgive me if my questions are >elementary. My company is in the process of changing from a legacy >enterprise-wide software package to a software package written in >Informix 4GL with an Informix 7.3 database. That's an oxymoron, surely? > We are getting ready to start moving data from our current system >over to the Informix database. I know there are several utilities >under Informix that enable the loading of data. My question is this: >How do these utilities handle the repetitive loading of the same data? >For example let's say I have an inventory related table that contains >item_number, description, quantity_onhand, qty_committed, qty_on_order >with item_number being the primary key. I know the item_number and >description columns won't change much so I want to load these now. >However, the columns that contain quantities will constantly be >changing as orders are placed, shipped, and P.O.'s are received. So I >can load them now but will have to obviously reload these columns >right before we are ready to go live. If I load the table with all >the columns now but just want to load in the quantities at a later >time can I do this? Will it fail because the primary key already >exists? Will it over-write the existing record, erasing the fields >that I don't load this second time? Do all of the Informix utilities >handle this type of load in the same manner? If the Informix >utilities cannot handle this type of database loading are there 3rd >party utilities that can do this? Depends on how you do it. Depends on how you do it. Depends on how you do it. Depends on how you do it. I don't know of any. >I know my example is pretty simple. In this case why not just load >all the fields again? But in my actual environment there are several >tables that have many columns. A lot of these columns have pretty >static data. We would like to be able to load these somewhat static >columns far in advance of the go live time. And then just load the >non-static fields at the last minute. I can tell that you're already making a swift transition to relational technology. Anyway, one way of doing this would be to load the latest data into a copy of the database and generate a bunch of UDPATE statements to copy over the latest values into the "real" database. Or you could use 4GL to do the same thing. Or you could do a fresh load (which is probably my preference anyway). ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com