The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 10: Integrating FILESTREAM with other SQL Server Featuressp_configure 'show advanced options', 1;GORECONFIGURE;GOsp_configure 'max text repl size', -1;GORECONFIGURE;GOListing 10-1:Using T-SQL to change the maximum replication data size.FILESTREAM replication and theUNIQUEIDENTIFIER columnIn Chapter 2, we discussed the fact that FILESTREAM columns can be added to atable only if it has a UNIQUEIDENTIFIER column that is marked as a ROWGUIDCOLwith a UNIQUE constraint. When replicating FILESTREAM columns with theFILESTREAM attribute, we must ensure that the UNIQUEIDENTIFIER column isalso selected for replication and that the UNIQUE constraint replicated along withthe UNIQUEIDENTIFIER column.If we remove the UNIQUEIDENTIFIER column from the publication, or decide not toreplicate the UNIQUE constraint, the FILESTREAM attribute will not be replicated to thesubscriber; it will be replicated as a VARBINARY(MAX) column, even if we set the ConvertFILESTREAM to MAX data types to FALSE.When a replication requirement exists, it is especially important to consider how togenerate the values for the UNIQUEIDENTIFIER column of FILESTREAM tables. Anew GUID value can be generated using either NEWID() or NEWSEQUENTIALID().Using NEWSEQUENTIALID() is recommended over NEWID() because it provides betterreplication performance and less fragmentation of the data. It should be noted that usingNEWSEQUENTIALID() is only supported in a DEFAULT constraint and this may not beappropriate for a particular scenario.357