This method allows external prefilters and term breakers to set an error in the database server by providing an error code and error string. The database server rolls back the current operation and returns the error code and string to the user in the following form:

"Error from external library: -<error_code>: <error_string>"

error_code must be a positive integer greater than 17000.

error_string must be a null-terminated string.

str_len is the length of error_string, in bytes.

This method allows external prefilters and term breakers to log messages to the database server log.

message must be a null-terminated string.

msg_len is the length of message, in bytes.

External prefilters and term breakers must periodically call this method to check if the current operation has been interrupted. This method returns 1 if the current operation was interrupted, and 0 if it was not interrupted. In the case of returning 1, the caller should stop further processing and return immediately.

For internal use. A pointer to the database server context.