The maximum number of columns you can create in a table is:
1024 for fixed-length columns in both all-pages-locked (APL) and data-only-locked (DOL) tables
254 for variable-length columns in an APL table
1024 for variable-length columns in an DOL table
The maximum size of a column depends on:
Whether the table includes any variable- or fixed-length columns.
The logical page size of the database. For example, in a database with 2K logical pages, the maximum size of a column in an APL table can be as large as a single row, about 1962 bytes, less the row format overheads. Similarly, for a 4K page, the maximum size of a column in a APL table can be as large as 4010 bytes, less the row format overheads. See Table 1-1 for more information.
