Solution Guide for Migrating Oracle on UNIX to SQL Server - Willy .Net

90Developing: Databases — <strong>Migrating</strong> SchemasCreate Filegroups <strong>for</strong> the TablespacesFilegroups in SQL Server are similar to tablespaces in <strong>Oracle</strong>. They are used to logicallygroup storage. When a database is created in SQL Server, it has one filegroup bydefault. Based on the number of tablespaces that the schema uses, additional filegroupshave to be created in the newly created database.Every database is created with a default primary filegroup that cannot be renamed ordropped. As a result, one of the tablespaces will have to map to the primary filegroupduring migration. Additional secondary or user filegroups can be created with userspecifiednames.In <strong>Oracle</strong>, tablespaces are created as locally managed or dictionary managed. The typeof tablespace determines what storage parameters can be used. Creating filegroups issimilar to creating tablespaces under <strong>Oracle</strong> except that a filegroup is added to a specificSQL Server database. Filegroups added to a database are called secondary filegroups,and they can be added to any database. Datafiles are added separately from thedefinition of a filegroup.The following two options are available <strong>for</strong> creating a filegroup. To create a filegroup using Enterprise Manager, follow these steps:1. Expand Databases and right-click Properties of the database to which thefilegroup has to be added.2. In the Database Properties window, left-click the Filegroups pane.3. Type the filegroup name in the next available empty line that follows the filegrouplisting. To add a filegroup to a database using T-SQL, execute the followingstatement:ALTER DATABASE database_nameADD FILEGROUP filegroup_nameAdd Datafiles to FilegroupsStorage has to be allocated in the SQL Server database to meet the requirements of theschema being migrated. Datafiles are added to filegroups much as datafiles are added totablespaces in <strong>Oracle</strong>.Adding a datafile in SQL Server is similar to the process used in <strong>Oracle</strong>. Thecharacteristics that can be set are related to auto-growth and are similar in function to<strong>Oracle</strong>'s AUTOEXTEND feature. An additional characteristic that does not exist in <strong>Oracle</strong>is the logical file name.Datafiles can be added to the primary filegroup as well as any secondary filegroups eitherthrough Enterprise Manager or using T-SQL. To add a datafile by using Enterprise Manager, follow these steps:1. Expand Databases and right-click Properties of the database to which thefilegroup has to be added.2. In the Database Properties window, left-click the Data Files pane.3. Add file in<strong>for</strong>mation in the next available empty line in the file listing. In the filegroupcolumn, select the filegroup name from the drop-down list. Also set the growthcharacteristics <strong>for</strong> the file.