Changing Table Structures - Mastering phpMyAdmin 3.1 for Effective MySQL Management - page 106

We will now add an index on the title. However, we want to restrict the length of
this index to reduce the space used by the on-disk index structure. The Create an
index on 1 columns option is appropriate. So, we click Go . In the next screen, we
specify the index details as shown here:

Here is how to fill in this panel:

• Index name : A name we invent

• Index type : We can choose INDEX or UNIQUE

• Field : We select the field that is used as the index, which is the title field

• Size : We enter 30 instead of 100 (the complete length of the field) to

save space in the table's physical portion that holds index data

After saving this panel, we can confirm from the following screenshot that the index
is created and does not cover the entire length of the title field:

Multi-field indexes and index editing
In the next example, we assume that in a future application we will need to find the
topics written by a speciic author in a speciic language. It makes sense to expand
our author_id index, adding the language field to it.