Re: Database Design Efficiency Question
Date: Tue, 28 Jan 1992 23:30:18 GMT
Message-ID: <1992Jan28.233018.4849_at_syacus.acus.oz.au>
elel_at_cbnewsd.att.com (eric.edberg) writes:
>Only some of the fields (appx 10%) in any tabel may
>contain data at any time; The rest will not be
>populated == (char *NULL) or a LONG INT that contains no
>value.
> Is there a mechanism whereby I can define field(s)
> in the table that have their space dynamically allocated
> by oracle during a ProC insert ?
>
Fields that are NULL take up a minimum space, so don't worry about the efficiency because of this.
If you're really worried, then do a formal sub-typing analysis of your schema and break your tables up. This will introduce more complexity into your application to manage the subtypes, but can often be worth it. Sub-types also make using SQL by users trickier. After all its only a relational database and the relational model has a lot of these kinds of problems lurking around.
peterr
Peter Russell (Systems Specialist)
peterr_at_syacus.acus.oz
ACUS - The Australian Centre for Unisys Software Phone: +61 2 390 1383
FAX : +61 2 390 1391 Received on Wed Jan 29 1992 - 00:30:18 CET