What's the most efficient way to insert thousands of records into a table (MySQL, Python, Django)

Question

I have a database table with a unique string field and a couple of integer fields. The string field is usually 10-100 characters long.

Once every minute or so I have the following scenario: I receive a list of 2-10 thousand tuples corresponding to the table's record structure, e.g.

[("hello", 3, 4), ("cat", 5, 3), ...]

I need to insert all these tuples to the table (assume I verified neither of these strings appear in the database). For clarification, I'm using InnoDB, and I have an auto-incremental primary key for this table, the string is not the PK.

My code currently iterates through this list, for each tuple creates a Python module object with the appropriate values, and calls ".save()", something like so:

@transaction.commit_on_success
def save_data_elements(input_list):
    for (s, i1, i2) in input_list:
        entry = DataElement(string=s, number1=i1, number2=i2)
        entry.save()

This code is currently one of the performance bottlenecks in my system, so I'm looking for ways to optimize it.

For example, I could generate SQL codes each containing an INSERT command for 100 tuples ("hard-coded" into the SQL) and execute it, but I don't know if it will improve anything.

Do you have any suggestion to optimize such a process?

Thanks

Answer 1

You can write the rows to a file in the format "field1", "field2", .. and then use LOAD DATA to load them

data = '\n'.join(','.join('"%s"' % field for field in row) for row in data)
f= open('data.txt', 'w')
f.write(data)
f.close()

Then execute this:

LOAD DATA INFILE 'data.txt' INTO TABLE db2.my_table;

Reference

Answer 2

For MySQL specifically, the fastest way to load data is using LOAD DATA INFILE, so if you could convert the data into the format that expects, it'll probably be the fastest way to get it into the table.