The following SQL Anywhere features are not supported on remote data:
ALTER TABLE statement against remote tables.
Triggers defined on proxy tables.
Foreign keys that refer to remote tables.
READTEXT, WRITETEXT, and TEXTPTR functions.
Positioned UPDATE and DELETE statements.
UPDATE and DELETE statements requiring an intermediate temporary table.
Backward scrolling on cursors opened against remote data. Fetch statements must be NEXT or RELATIVE 1.
If a column on a remote table has a name that is a keyword on the remote server, you cannot access data in that column. You can execute a CREATE EXISTING TABLE statement, and import the definition but you cannot select that column.