If you pass temp-tables across the network, the schema descriptor information can be quite substantial, which increases the overhead of the call. If the temp-tables are "wide," with many fields, and only one or a few rows are passed, then the schema information can far exceed the size of the data itself. In cases where the receiving procedure has a static temp-table definition of its own, this schema information is really not needed. Even in a case where the receiving procedure does not have a temp-table definition, schema details such as the field formats and Help strings and so forth might not be needed.

For this reason, there is a Temp-table Schema Marshal (-ttmarshal) startup parameter you can use to specify the amount of schema information marshaled for all temp-table parameters passed during an OpenEdge client session. There are also three temp-table attributes available to specify or reduce the amount of schema information marshaled for individual temp-tables. In any case, the temp-table can be an independent temp-table or a member of a ProDataSet.