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Re: Any issues with large database views?

From: <michael_bialik_at_my-deja.com>
Date: Mon, 01 Nov 1999 21:34:59 GMT
Message-ID: <7vl123$loa$1@nnrp1.deja.com>


Hi.

 There are some pros and cons ( as usual ) to use one large  table ( with let say 999 columns ) instead of joining 9  tables of 111 columns each in a view :

 Pros :

  1. If you always need most of your columns during data access - it will be much faster that way ( otherwise you must join 9 tables ).

 Cons :

  1. You must enlarge your db_block_size to accomodate the whole row and to prevent ( as possible ) row chaining and migration.
  2. Usually you don't need to access all 999 fields - so you will be able to group your fields by some common purpose and to save time during direct access and even seq. access as well.
  3. Your table is less manageable.

   Probably there more considerations, by I would go for 9 tables    instead of 1 ( unless the only Pro reason exists in your case ).

  HTH. Michael.
In article <7vkbt4$4ua$1_at_nnrp1.deja.com>,   clapoint149_at_my-deja.com wrote:
> Hello,
>
> I have the need to store records which will consist of several
> hundred but < 1000 fields. My current understanding is that for
Oracle
> 8 and above the table column limit is 1000 and for previous versions
of
> Oracle's database server the table column limit is 254. However, I
> have heard that even with the newer versions of the database server
> there are still issues with creating/using tables with more than 254
> columns. I personally do not know what these issues might be, nor do
I
> know if they actually translate as problems per se. What I am
> wondering, though, is if these issues (whatever they are) also apply
to
> large views (with several hundred columns) that join medium-sized
> tables (each with at most about 100 columns), which is how I prefer to
> store/access my large records. My guess is that large views are
immune
> since any table problems most likely stem from physical storage
design,
> but I do not know for sure. Could someone shed some light on any
> issues related to large database tables and views? Thanks.
>
> Cary
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Mon Nov 01 1999 - 15:34:59 CST

Original text of this message

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