Why is executemany slow in Python MySQLdb?

Question

I am developing a program in Python that accesses a MySQL database using MySQLdb. In certain situations, I have to run an INSERT or REPLACE command on many rows. I am curren

Answer 1

Try lowercasing the word 'values' in your query - this appears to be a bug/regression in MySQL-python 1.2.3.

MySQL-python's implementation of executemany() matches the VALUES clause with a regular expression and then just clones the list of values for each row of data, so you end up executing exactly the same query as with your first approach.

Unfortunately the regular expression lost its case-insensitive flag in that release (subsequently fixed in trunk r622 but never backported to the 1.2 branch) so it degrades to iterating over the data and firing off a query per row.