add LOAD DATA LOCAL INFILE to speed up data insert

[slowtech]

As we all know, the speed of load data infile is faster than insert in MySQL.

so i add load data local infile to speed up data insert.

based on this, i make some tests.

Here are the test results.

Basically, load data local infile is 30% faster than insert.

BTW, by default, LOAD DATA LOCAL INFILE is not allowed to execute, we must set global local_infile=on before we use it.

I'm trying to support PgSQL, but unfortunately PgSQL doesn't support loading files from the client.