alzabo::runtime::index(3pm) [debian man page]

Alzabo::Runtime::Index(3pm)				User Contributed Perl Documentation			       Alzabo::Runtime::Index(3pm)

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 col-
       umn 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.

       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::Runtime::Table" object to which the index belongs.

AUTHOR

       Dave Rolsky, <autarch@urth.org>

perl v5.8.8							    2007-12-23					       Alzabo::Runtime::Index(3pm)

Alzabo::Runtime::UniqueRowCache(3pm)			User Contributed Perl Documentation		      Alzabo::Runtime::UniqueRowCache(3pm)

NAME

       Alzabo::Runtime::UniqueRowCache - Implements a row cache for Alzabo

SYNOPSIS

	 use Alzabo::Runtime::UniqueRowCache;

	 Alzabo::Runtime::UniqueRowCache->clear();

DESCRIPTION

       This is a very simple caching mechanism for "Alzabo::Runtime::Row" objects that tries to ensure that for there is never more than one row
       object in memory for a given database row.

       To use it, simply load it.

       It can be foiled through the use of "Storable" or other "deep magic" cloning code, like in the "Clone" module.

       The cache is a simple hash kept in memory.  If you use this module, you are responsible for clearing the cache as needed.  The only time it
       is cleared automatically is when a table update or delete is performed, in which case all cached rows for that table are cleared.

       In a persistent environment like mod_perl, you should clear the cache on a regular basis in order to prevent the cache from getting out of
       sync with the database.	A good way to do this is to clear it at the start of every request.

METHODS

       All methods provided are class methods.

       * clear
	   This clears the entire cache

       * clear_table( $table_object )
	   Given a table object, this method clears all the cached rows from that table.

       * row_in_cache( $table_name, $row_id )
	   Given a table name and a row id, as returned by the "Alzabo::Runtime::Row->id_as_string" method, this method returns the matching row
	   from the cache, if it exists.  Otherwise it returns undef.

       * delete_from_cache( $table_name, $row_id )
	   Given a table name and a row id, as returned by the "Alzabo::Runtime::Row->id_as_string" method, this method returns the matching row
	   from the cache.

       * write_to_cache( $row_object )
	   Given a row object, this method stores it in the cache.

AVOIDING THE CACHE

       If you want to not cache a row, then you can pass the "no_cache" parameter to any table or schema method that creates a new row object or a
       cursor, such as "Alzabo::Runtime::Table->insert()", "Alzabo::Runtime::Table->rows_where()".

AUTHOR

       Dave Rolsky, <autarch@urth.org>

perl v5.8.8							    2007-12-23				      Alzabo::Runtime::UniqueRowCache(3pm)