My problem occurred as follows:
I use the APIs of mysqldb , the codes like this:
conn = MySQLdb.connect(host='192.168.1.16', user='henry', passwd='password', db='test', charset='utf8')
cur = conn.cursor()
It is ok, the connect mysql is a success, and it works as well with this:
select count(*) from songs; everthing is allright.
But if I use sql like this:
select * from songs;
The error is:
connect mysqldb error. the songs table has 5000000 rows.
MySQLdb save all rows and columns of the select statement in the memory, in your case is 5M rows * n columns, so the error may be caused by two reason:
1. the result is too large to be saved in memory.
2. the result is too large to be transferred via the network connection.
You may try to just return a few rows, not all of them. If you really want to retrieve the entire table, complete it in several times.
James Bear is correct that you are probably running out of memory. You should use a cursor so that you only load the data you need when you need it.
You can put cursorclass=MySQLdb.cursors.SSCursor in the connect function, and that should fix the problem.
