how to comprehend the first start the new capture process

[oldboy]

the following is come from Oracle stream concept:

If a new capture process will use a new LogMiner data
dictionary, then, when you first start the new capture process,
some time might be required to populate the new LogMiner data
dictionary. A new LogMiner data dictionary is created if a
non-NULL first SCN value was specified when the capture process
was created.

if so,is it slow the first start capture process ?