SQL/MX 3.x Reference Manual (H06.22+, J06.11+)

Limits
HP NonStop SQL/MX Reference Manual—640322-001
C-2
Referential constraints A table can have an unlimited number of referential
constraints, and you can specify the same foreign key in
more than one referential constraint, but you must
define each referential constraint separately.
Schema names 128 characters in length.
Tables ANSI names are three-part name of the form
catalog.schema.object, where each part can be up
to 128 characters long.
The maximum length of a row is 4036 bytes for 4K
blocks and 32708 bytes for 32K blocks, but not all of
that is available. Depending on data types you use,
NonStop SQL/MX might use some bytes for internal
use.
The clustering key for a table cannot be longer than
2010 bytes for 4K blocks and 2048 bytes for 32K
blocks.