Updating an identity column sql server
A computed column is a virtual column that is not physically stored in the table, unless the column is marked PERSISTED.
The column is computed from an expression that uses other columns in the same table.
TEXTIMAGE_ON is not allowed if there are no large value columns in the table. If "default" is specified, or if TEXTIMAGE_ON is not specified at all, the large value columns are stored in the default filegroup.
The storage of any large value column data specified in CREATE TABLE cannot be subsequently altered.
Any computed columns that are used as partitioning columns of a partitioned table must be explicitly marked PERSISTED.
For more information, see ALTER TABLE (Transact-SQL).
TEXTIMAGE_ON Indicates that the text, ntext, image, xml, varchar(max), nvarchar(max), varbinary(max), and CLR user-defined type columns (including geometry and geography) are stored on the specified filegroup.
is specified, the table is stored in the named filegroup. If "default" is specified, or if ON is not specified at all, the table is stored on the default filegroup.
The storage mechanism of a table as specified in CREATE TABLE cannot be subsequently altered.