Binlog file structure
All events have a common general structure consisting of an event header followed by event data:
+===================+
| event header |
+===================+
| event data |
+===================+
header length = x bytes
data length = (event_length - x) bytes
fixed data length = y bytes variable data length = (event_length - (x + y)) bytes
x is given by the header_length field in the format description event (FDE). Currently, x is 19, so the extra_headers field is empty.
y is specific to the event type, and is given by the FDE. The fixed-part length is the same for all events of a given type, but may vary for different event types.
The fixed part of the event data is sometimes referred to as the "post-header" part. The variable part is sometimes referred to as the "payload" or "body."
structure1.jpg