Answer

For the columns in a table, there is a maximum limit of 1024 columns in a table. SQL Server does have a wide-table feature that allows a table to have up to 30,000 columns instead of 1024. SQL Server 2008 and up have a Sparse Columns feature that can optimize storage when you have many columns with NULL values in the rows of the table. You are still limited to 8060 bytes of data per row. However, Sparse Columns and the wide-table feature in SQL Server are not support with P8 CPE at this time. One possible way to avoid the 1024 maximum number of columns is to create multiple object stores for different classes of objects, for different business needs.

A table can contain a maximum of 8,060 bytes per row. However, Row-Overflow Data is supported in SQL Server 2008 and up. Starting in SQL Server 2008, this restriction is relaxed for tables that contain varchar, nvarchar, varbinary, sql_variant, or CLR user-defined type columns. The length of each one of these columns must still fall within the limit of 8,000 bytes; however, their combined widths can exceed the 8,060-byte limit. This is explained on the following Microsoft web page:
https://technet.microsoft.com/en-us/library/ms186981(v=sql.105).aspx
P8 also provides support for a CE "Long String" property data type, with the supporting column created as a large object (e.g. ntext) data type, which allows the strings to greatly exceed 8060 bytes.