Sybase NNTP forums - End Of Life (EOL)

The NNTP forums from Sybase - forums.sybase.com - are now closed.

All new questions should be directed to the appropriate forum at the SAP Community Network (SCN).

Individual products have links to the respective forums on SCN, or you can go to SCN and search for your product in the search box (upper right corner) to find your specific developer center.

changing db structures at runtime..

3 posts in Windows NT Last posting was on 1998-01-18 00:32:25.0Z
buckwheat Posted on 1998-01-17 04:36:57.0Z
From: buckwheat@microa.com
Subject: changing db structures at runtime..
Date: Sat, 17 Jan 1998 04:36:57 GMT
Message-ID: <34c034af.6983969@forums.sybase.com>
X-Newsreader: Forte Free Agent 1.11/32.235
Newsgroups: sybase.public.sqlserver.nt
Lines: 8
Path: forums-1-dub!forums-master.sybase.com!forums.powersoft.com
Xref: forums-1-dub sybase.public.sqlserver.nt:5295
Article PK: 1081424

i know this is academic, but plz humor a newbie...

does sybase (or any other sql) allow changes to table/db definitions
on the fly at runtime (active db)?

for instance, changing/adding/deleting field size or type, index defs,
relationships and the like.

thanx - greg


John McVicker Posted on 1998-01-18 00:32:25.0Z
Message-ID: <34C14D99.3D864891@sybase.com>
Date: Sat, 17 Jan 1998 19:32:25 -0500
From: John McVicker <mcvicker@sybase.com>
Reply-To: mcvicker@sybase.com
Organization: Sybase Professional Services
X-Mailer: Mozilla 4.04 [en] (Win95; U)
MIME-Version: 1.0
To: buckwheat@microa.com
Subject: Re: changing db structures at runtime..
References: <34c034af.6983969@forums.sybase.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Newsgroups: sybase.public.sqlserver.nt
Lines: 72
Path: forums-1-dub!forums-master.sybase.com!forums.powersoft.com
Xref: forums-1-dub sybase.public.sqlserver.nt:5292
Article PK: 1081373

Greg,
You can do just about anything on the fly.
You suggested a few (adding fields, etc).
Basically, you can get at all you need for Sybase RDBMS
products on the Web through http://sybooks.sybase.com.
Are you a current Sybase user? If so, the document you
need to look at is the Sybase SQL Server or Adaptive
Server Reference Guide. There, you'll need to look at
commands CREATE TABLE, ALTER TABLE,
CREATE INDEX, DROP INDEX and more. If you
want, we could address specifics - list a few of your
major concerns out in the forum and we can go over them.

I don't think we'll have any problems addressing them.
Also, when listing them out, give business reasons behind
them. Such as:
Problem: Add column to table
Reason: Every so often, the incoming feed from our data
supplier changes. Usually an additional column arrives which
we must place into an existing table. How can I do that?

Problem: Rebuild Index on table
Reason: Sometimes, the developers place an index on a
table and it goes into production. Later, we realize that they
were totally wrong when they determined the index columns
and we want to remove some. We need to rebuild the
index. How does that affect my user-base, and when can
I re-create the index?

Most RDBMS systems, because they are multi-user, end up with
some limitations due to concurrency constraints. I cannot re-order
a table's columns, for instance, because many users may be online
and as such, just cannot take the table off-line and do it without
affecting their usefullness. That example has two sides. If that
problem really needs to exist in a system, you need to put logic
in your application to allow for two or more data tables and possibly
be able to switch between them so that downtime is eliminated.
Most applications, though, do not take that into consideration
early enough in their development cycle and end up with trying
to shoehorn such operations into the production environment.
So, if you can write down all business issues prior to development,
you can greatly enhance your success for the project by layout
out the expectations and meeting them early in the development
cycle.

buckwheat@microa.com wrote:

> i know this is academic, but plz humor a newbie...
>
> does sybase (or any other sql) allow changes to table/db definitions
> on the fly at runtime (active db)?
>
> for instance, changing/adding/deleting field size or type, index defs,
> relationships and the like.
>
> thanx - greg

--
John McVicker
Principal Consultant, District Lead Architect
Sybase Professional Services
Pennsylvania/New Jersey District
301-896-1765
mcvicker@sybase.com, mcvicker@bellatlantic.net,
JohnMcVicker@compuserve.com

http://www.sybase.com
http://www.powersoft.com
http://www.isug.com


Jacek Borowiec Posted on 1998-01-17 12:21:12.0Z
From: "Jacek Borowiec" <jacek_borowiec@glowka.pol.pl>
References: <34c034af.6983969@forums.sybase.com>
Subject: Re: changing db structures at runtime..
Date: Sat, 17 Jan 1998 13:21:12 +0100
Lines: 17
X-Newsreader: Microsoft Outlook Express 4.71.1712.3
X-MimeOLE: Produced By Microsoft MimeOLE V4.71.1712.3
Message-ID: <hcihTlzI9GA.138@forums.powersoft.com>
Newsgroups: sybase.public.sqlserver.nt
Path: forums-1-dub!forums-master.sybase.com!forums.powersoft.com
Xref: forums-1-dub sybase.public.sqlserver.nt:5293
Article PK: 1081374

Every changes you can make "on the fly".
To say more, you can do that on existing data.
Just use "ALTER TABLE" statement.

buckwheat@microa.com napisa³(a) w wiadomo¶ci:
<34c034af.6983969@forums.sybase.com>...

>i know this is academic, but plz humor a newbie...
>
>does sybase (or any other sql) allow changes to table/db definitions
>on the fly at runtime (active db)?
>
>for instance, changing/adding/deleting field size or type, index defs,
>relationships and the like.
>
>thanx - greg