The TBCLOSE service terminates processing of the specified table and deletes the virtual storage copy, which is then no longer available for processing.
If the table was opened in WRITE mode, TBCLOSE copies the table from virtual storage to the table output library. In this case, the table output library must be allocated to a ddname of ISPTABL or defined by a LIBDEF service request before invoking this service. When storing a table in an output library, the user can give it a new name. The table name used in the output library must not be an alias name.
If the table was opened in NOWRITE mode, TBCLOSE simply deletes the virtual storage copy.
Table output can be directed to a table output library other than the default library specified on the table output ISPTABL DD statement. The library to be used must be allocated before table services receives control. Thus, an application can update a specific table library. This is particularly useful for applications that need to maintain a common set of tables containing their data.
A TBCLOSE request for a shared table causes the use count in the table for that logical screen to be decremented by one. If the use count for all logical screens is zero, the TBCLOSE service is performed. If the count is not zero, a TBSAVE service is performed. This leaves the table available for continued processing in any screen that still has a use count greater than zero.
Issuing a TBCLOSE with the LIBRARY parameter for a table is not related to closing the data set allocated to that ddname. However, if the LIBDEF service with the DATASET keyword is used to define the alternate library, the data set may be closed and freed by deleting the corresponding LIBDEF specification.