NAME

       Alzabo::Index - Index objects

SYNOPSIS

         foreach my $i ($table->indexes)
         {
            foreach my $c ($i->columns)
            {
               print $c->name;
               print '(' . $i->prefix($c) . ')' if $i->prefix($c);
           }
        }

DESCRIPTION

       This object represents an index on a table.  Indexes consist of columns and optional
       prefixes for each column.  The prefix specifies how many characters of the columns should
       be indexes (the first X chars).  Some RDBMS's do not have a concept of index prefixes.
       Not all column types are likely to allow prefixes though this depends on the RDBMS.  The
       order of the columns is significant.

METHODS

   columns
       Returns an ordered list of the "Alzabo::Column" objects that are being indexed.

   prefix ("Alzabo::Column" object)
       A column prefix is, to the best of my knowledge, a MySQL specific concept, and as such
       cannot be set when using an RDBMSRules module for a different RDBMS.  However, it is
       important enough for MySQL to have the functionality be present.  It allows you to specify
       that the index should only look at a certain portion of a field (the first N characters).
       This prefix is required to index any sort of BLOB column in MySQL.

       This method returns the prefix for the column in the index.  If there is no prefix for
       this column in the index, then it returns undef.

   unique
       Returns a boolean value indicating whether the index is a unique index.

   fulltext
       Returns a boolean value indicating whether the index is a fulltext index.

   function
       For function indexes, this returns the function being indexed.

   id
       The id is generated from the table, column and prefix information for the index.  This is
       useful as a canonical name for a hash key, for example.

       Returns a string that is the id which uniquely identifies the index in this schema.

   table
       Returns the "Alzabo::Table" object to which the index belongs.

AUTHOR

       Dave Rolsky, <autarch@urth.org>