This feature allows you check that DSV data types match the data types on the KeyColumns and NameColumn of dimension attributes. It displays any discrepancies and lets you fix them with the click of a button:
The main scenario this feature is designed to help with is as follows. If you build a dimension attribute off a varchar(100) column, then you lengthen that column to varchar(200) in the SQL database, then refresh your DSV, that length change doesn’t get replicated to the KeyColumn or NameColumn of dimension attributes which still have a DataSize property of 100. If any data in that column is longer than 100, you will receive an error during cube processing that says, “The size specified for a binding was too small, resulting in one or more column values being truncated.”
To launch this feature, right click on the Dimensions folder in Solution Explorer:
When the window pops up (seen above), the following columns are shown:
Take special notice of any rows which are red. Those rows represent data type (not just length) changes which may cause cells on the Dimension Usage tab to become invalid. After clicking the OK button to have BI Developer Extensions change the data types on the dimension attributes, you’ll need to open the Dimension Usage tab on all your cubes and look for red squiggly lines. If there are any errors, first click the … button in that cell to pop open the Define Relationship editor, then click OK. Wait a few seconds and see if the red squiggly goes away. If not, you may need to delete and recreate the relationship (click the … button again, change the relationship type to No Relationship, click OK, then click the … button again and redefine the relationship). If the red squiggly occurs on a linked measure group, you may need to delete that measure group and use the Linked Objects Wizard to recreate that linked measure group.
Tip: You can copy the data from the Dimension Data Type Discrepancy Check dialog with Ctrl-A then Ctrl-C and then paste it into Excel. If you feel the need to manually double check the changes BI Developer Extensions makes, this lets you copy and paste the list. The red coloring does not get copied to Excel, but red rows are generally rows where Old Data Type does not match New Data Type.
Tip: After you refresh the DSV, run Dimension Data Type Discrepancy Check to quickly check whether any dimension attribute data types or lengths need to change.