[Pager] Pager_Wrapper_DB...and so on

Hi everybody ! I am new with PEAR, but I have looking for docs about pager through the threads here. I found that I can use Pager to obtain a pretty good pagination when extracting data from a DB. That is fine. I guess that with large tables, with lots records I should use a wrapper to extract only needed records. Lorenzo Alberton suggest a Pager_Wrapper_DB function to deal with that. (http://seagull.phpkitchen.com/docs/wakka.php?wakka=PagingRecordsets and http://cvs.php.net/co.php/pear/Pager/examples/Pager_Wrapper.php) Is this a part of PEAR? If not is there an "official" implentation in the PEAR project somewhere (I did not find one). 1/ Does anybody know another implentation of such a feature ? 2/ How many records means "large table" and "lot of records" ? Thanks Mos