Speed up INSERT statements for memory logging

Some ideas:
1. Use insert delayed
To increase performance for MyISAM tables, for both LOAD DATA INFILE and INSERT, enlarge the key cache by increasing the key_buffer_size system variable. See Section 7.9.2, “Tuning Server Parameters”.
2. Write memory logs to cache, then when the cache gets to 100, do a single line 100 insert. This reduces connection time.
3. Lock the table before the insert