May 6, 2009 at 9:47 am
Hi
We have a lagecy system where long back some one migrated from sql server 65 to sql server 2000(80) but they kept comptatibility level to 65.
I could see their are several tables with ansi null off. so I cannot create index on view.
and old dba told me not to change this... can anybody tell me what would be the impact on application if we change it to 80 ie. what precousions I should take todo so.
Appriciate any help.
Thanx
Vinay
Thanx.
Vinay
http://rdbmsexperts.com/Blogs/
http://vinay-thakur.spaces.live.com/
http://twitter.com/ThakurVinay
May 6, 2009 at 9:59 am
ANSI_NULL property identifies how NULL values are evaluated by SQL Server. Basically query behavior changes with this value set.
ANSI SQL-92 standard basically states that when comparing two null values, the result will be FALSE. SQL Server can be configured to evaluate this condition to be TRUE with this setting turned off.
ANSI SQL-92: NULL NULL
Non ANSI SQL-92: NULL=NULL
More information on this can be found in SQL Server's books online articles.
http://msdn.microsoft.com/en-us/library/ms188048.aspx
With all that being said, the answer to your question specifically is - setting this database to compatability mode 80 may result in some unexpected query result sets, especially if you're changing the way NULL values are evaulated by the query engine.
Also, be aware with an indexed view, SQL Server Standard Edition handles this somewhat differently than SQL Server Enterprise. Basically the Standard edition - you have to specifiy in the query code (or by use of a view, tbf, or stored proc) to use the indexed view, while in Enterprise, SQL Server automatically uses the indexed view.
http://msdn.microsoft.com/en-us/library/ms181151.aspx
"Indexed views can be created in any edition of SQL Server. In SQL Server Enterprise, the query optimizer automatically considers the indexed view. To use an indexed view in all other editions, the NOEXPAND table hint must be used."
May 6, 2009 at 10:21 am
I eloborate my question:
1. What would be impact of changing sql server 65 compatibility to 80?
2. All tables are having ansi NULL off, that will not change automatically, Do I have to create new tables and with ansi null on and export data?
3. Application is old and working good, what would be impact? do we have to change the application where "=NULL" with something like isnull() or is null?
4. We are having " in application, (quate identifier on " ) so do we have to change the application with ',
This is all i could think now....add on more if anyone feel so.
Appriciate any help.
Vinay
Thanx.
Vinay
http://rdbmsexperts.com/Blogs/
http://vinay-thakur.spaces.live.com/
http://twitter.com/ThakurVinay
May 6, 2009 at 10:23 am
I elaborate my question:
1. What would be impact of changing sql server 65 compatibility to 80?
2. All tables are having ansi NULL off, that will not change automatically, Do I have to create new tables and with ansi null on and export data?
3. Application is old and working good, what would be impact? do we have to change the application where "=NULL" with something like isnull() or is null?
4. We are having " in application, (quote identifier on " ) so do we have to change the application with ',
This is all i could think now....add on more if anyone feel so.
Appreciate any help.
Vinay
Thanx.
Vinay
http://rdbmsexperts.com/Blogs/
http://vinay-thakur.spaces.live.com/
http://twitter.com/ThakurVinay
May 13, 2009 at 12:27 pm
Vinay (5/6/2009)
I elaborate my question:3. Application is old and working good, what would be impact?
Appreciate any help.
Vinay
Vinay, I can't remember back to 6.5, the first SQL platform I started on. My question is, if it's "working good", what benefit do you think you'll acheive by moving it to SQL2000 compatability? What's the underlying thinking that is driving your quest, simply an indexed view? If it's a canned application, is it certified on a SQL 2000 platform?
-- You can't be late until you show up.
May 13, 2009 at 2:21 pm
Thanx Terry for reply.
System is doing good so far, but I feel if we could change the compatibility. It will generate good compile and execition plan and will work better.
Long back old DBA's migrated to 2000, but the tables still has Ansi NULL off (other settings as well). was thinking to improve the performance and efficiency of the system but looks like it will be a BIG task includes application level changes... so I also think its better to go as it is going... and try to handle what all is possible(As business is not ready to invest more on this).
Thanx
Vinay
Thanx.
Vinay
http://rdbmsexperts.com/Blogs/
http://vinay-thakur.spaces.live.com/
http://twitter.com/ThakurVinay
Viewing 6 posts - 1 through 5 (of 5 total)
You must be logged in to reply to this topic. Login to reply