The logmech_name is an 8-byte field supplied by the application and derived from the .logmech command or statement, or the mechanism name list box of the logon dialog box. It is located in the eight bytes after the existing using-data-count field. If a default session character set is in use, the application must ensure that only a valid mechanism name is passed (single-byte LATIN1, left-justified, case-insensitive, and padded with blanks), performing conversion, if necessary. The mechanism name will be converted internally to the OID corresponding to the indicated mechanism; the application does not need to know anything about OIDs.
The logmech_data_ptr is a 32- or 64-bit pointer to a variable-length field (maximum of 65535 bytes) supplied by the application and derived from the .logdata command or statement, or the mechanism data text box of the logon dialog box. The logmech_data_ptr immediately follows the logmech_name. In 32-bit implementations, a 4-byte unused field will precede the 32-bit logmech_data_ptr; in 64-bit implementations, logmech_data_ptr will occupy the full 8 bytes following logmech_name.
The logmech_data_len is a 32-bit unsigned integer supplied by the application and specifies the length of the mechanism data in bytes. It is located immediately following logmech_data_ptr. The maximum allowable value for logmech_data_len is 64 KB.
These fields are only examined at connect time (that is, when the DBFCON function of DBCHCL is requested) or if connection is lost and CLI is set up to reconnect automatically.
The associated data will be passed as-is to the indicated mechanism. It is the responsibility of the user to ensure that the mechanism can handle a specific character set.