Alzabo (version 0.64) - Alzabo::Runtime::Index

Index



NAME

Alzabo::Runtime::Index - Index objects


SYNOPSIS

  use Alzabo::Runtime::Index;


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.


INHERITS FROM

Alzabo::Index

Note: all relevant documentation from the superclass has been merged into this document.


METHODS

columns

Returns

An ordered list of the Alzabo::Runtime::Column objects that are being indexed.

prefix (Alzabo::Runtime::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.

Returns

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 or not the index is a unique index.

fulltext

Returns

A boolean value indicating whether or not the index is a fulltext index.

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 for the index.

table

Returns

The Alzabo::Runtime::Table object to which the index belongs.


AUTHOR

Dave Rolsky, <autarch@urth.org>