[support] MyISAM vs InnoDB

[Daniel Carrera]

Michael Prasuhn wrote:
> Well there are some gotcha conditions, if you have a WHERE clause in 
> your update, it must be using an index, otherwise it has to do a table 
> scan, and locks the whole table. Also, any inserts using an 
> auto-increment column will lock the entire table to prevent duplicate 
> values.

Hmm... the auto-increment thing could be an issue. This leads me to two 
new questions:

1. Is it necessary for every row in the table to be unique?
2. Is it necessary for the primary key to be unique?

Currently, the table looks like this:

id, student_id, teacher_id, marks, date


The id is a primary key with auto_increment, but honestly I don't need 
it for anything. I normally search for student_id, so that's an index. 
Can I make it a primary key and drop the 'id' field? Then I won't have 
auto-increment and so I'll get non-blocking 50-INSERTs :-)

Would this work?


> Please see 
> http://2bits.com/articles/mysql-innodb-performance-gains-as-well-as-some-pitfalls.html for 
> some examples.

*Click*

Cheers,
Daniel.