Re: Ultimate Question: Oracle, MSSQL, Others vs MYSQL LIMIT Statement

... further...
When an update causes a row to grow (e.g. my storing a longer variable length value). Then the DBMS will try to shuffle the other rows in the page to squeeze teh row in. When that fails the row has to move to another page and it leaves an indirection pointer (like the forwarding address you leave when you move :-). This indirection hurts performance (one more IO).
Reorg will remove those inderections and eliminate free space between rows that occurs if a row gets inserted in the place where a bigger row got deleted, or where a rows' variable fields shrank. Reorg may also try to enhance any chosen clustering of the data.

Cheers
Serge

-- 

Serge Rielau
DB2 UDB SQL Compiler Development
IBM Software Lab, Toronto

Try the DB2 UDB V8.1 beta at
http://www-3.ibm.com/software/data/db2/