conventional path/ sql evaluation
Im having some difficulty undrestanding below note
"Use Direct Path – Direct path exports (DIRECT=Y) allow the export utility to skip the SQL evaluation buffer, whereas the conventional path export executes SQL SELECT statements. With direct path, the data is read from disk into the buffer cache, returning rows directly to the export client. This can offer substantial performance gains, depending on the actual data. When using the direct path, the recordlength parameter should also be used to optimize performance. "
Q: How does Direct path read data from disk into the buffer then ? if its not using select statment ? what is SQL evaluation buffer?
Thanks for your advice