MySQL Index is bigger than the data stored
I have a database with the following stats

    Tables     Data   Index   Total
    11     579,6 MB  0,9 GB  1,5 GB

So as you can see the Index is close to 2x bigger. And there is one table with ~7 million rows that takes up at least 99% of this.

I also have two indexes that are very similar

    a) indexA (int colA, varchar(10) colB)
    b) indexB (int colA, varchar(10) colB, varchar(20) colC)

Database Engine is InnoDB

My questions are:

1. Is there a way to find unused indexes in MySQL?
2. Are there any common mistakes that impact the size of the index?
3. Can indexA safely be removed?
4. How can you measure the size of each index? All I get is the total of all indexes.


MySQL Index is bigger than the data stored
===

I have a database with the following stats

    Tables     Data   Index   Total
    11     579,6 MB  0,9 GB  1,5 GB

So as you can see the Index is close to 2x bigger. And there is one table with ~7 million rows that takes up at least 99% of this.

I also have two indexes that are very similar

    a) indexA (int colA, varchar(10) colB)
    b) indexB (int colA, varchar(10) colB, varchar(20) colC)

Database Engine is InnoDB

My questions are:

1. Is there a way to find unused indexes in MySQL?
2. Are there any common mistakes that impact the size of the index?
3. Can indexA safely be removed?
4. How can you measure the size of each index? All I get is the total of all indexes.

