Adding Indexes to Persisted Computed Columns in SQL Server 2005 - SQL Server Performance
As a DBA, it is your job to weigh the pros and cons of using persisted (and possibly indexed) columns and to determine whether using them or not is beneficial to the overall performance of your application. If you are aware of any of your databases where computed columns are being queried a lot, and you are running SQL Server 2005, you should seriously evaluate whether or not making the computed column persisted, and indexing the column, will benefit the overall performance of your application
Adding Primary key column to existing table
If I remember correctly, MSSql Server doesn;t like making primary keys from nullable columns.You can accomodate this in an alter table by adding a default constraint then declare it as not null.Step 2
sql server - Why does simple ALTER TABLE command take so long on table with full-text index? - Database Administrators Stack Exchange
I'm not sure what your application requirements are but an approach that would make the schema change faster is to add it in as a nullable column with no default value and then perform an update in batches to assign 0 as the value for the column. In SQL Server 2012 the operation is much faster, see Online non-NULL with values column add in SQL Server 11 as it only updates the metadata of the table and does not actually update any row
SQL Server table columns under the hood
This is the layer at which you can look into sys.columns and see the table structure, or look at the table in SSMS object explorer and so on and so forth. When data is inserted into the new partition that is created after a column is dropped, the number of the maximum nullable columns in the new partition may be one less than the number of the maximum nullable columns in the old partition
For some reason this post came up top in Google when I was trying to find out why my t-sql syntax was not quite right for adding multiple columns to an already existing table using a single alter statement.BTW - Tilt's response to Darrick is priceless. The problem statement is this: Can you do ALTER TABLE X ALTER COLUMN Y, Z, Qwithout it being 3 separate operations.The answer is no.Only a maniac would go in and start hacking the sys tables
ALTER TABLE attempt failed, this explaination came through perfectly, tatero Log In or Register to post comments Preeti (not verified) on May 13, 2004 This is a very systematic solution given to a problem ususlly faced while migrating from Oracle to SQL 2000. To demonstrate this T-SQL activity, run the code that Listing 1 shows to create and populate the Orders2 and OrderDetails2 tables in the Northwind database
But do you know what will be the solution when ID column is referenced as foreign key in other multiple tables? because in this case it wouldnt let me delete that old ID column. can i chaneg the order of columns in a table as i dont want to disturb the column sequence of my primary key column after using the above suggested methods
The replication of schema changes is activated, and the replication has been running for years, including frequent schema changes (new column, new constraints, etc)
ALTER TABLE only allows columns to be added that can contain nulls, or have a DEFAULT definition specified, or the column being added is an identity or timestamp column, or alternatively if none of the previous conditions are satisfied the table must be empty to allow addition of this column. Fill in your details below or click an icon to log in: Email (required) (Address never made public) Name (required) Website You are commenting using your WordPress.com account
Alter Table Alter Column
Also, be aware that this will update all the rows in the table unless yo use a WHERE clause Reply to this comment Home Tuning Services Featured Articles How to cache stored procedure results using a hash key There are a lot of different design patterns that lend themselves to creating SQL Server Database Optimization Guide In the troubleshooting guide we went over the different physical bottlenecks that can Yet Another Temp Tables Vs Table Variables Article The debate whether to use temp tables or table variables is an old Using Union Instead of OR Sometimes slow queries can be rectified by changing the query around a bit
SQL Query to add a new column after a existing column in SQL Server 2005 - Stack Overflow
Your best bet is using Sql Server Management Studio, or play around with either dropping and re-adding the table, or creating a new table and moving the data over manually
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