Re: What's the performance impact of changing data type of primary key from INTEGER to CHAR(16)

There are several impacts to making this change. First your key will increase from 4 to 16 bytes. Over 2.5 million rows, thats 30,000,000 extra bytes for storage just for the rows. Then there's the indexes.... I am currently using a 10 byte character string as the primary key for a number of tables. I would like to make the move to using INTEGER, but there's no budget for those changes at the moment. It would depend on how it is implemented, but I suspect that you will lose the time between an equality check and a memcmp statement. It propbably won't kill you, but.... In any event, I am VERY interested in hearing what results you get. I can certainly use the results to drive a change in the other direction for my project. Thanks, Kevin -- mkmchu +------------------------------+-------------------------+----------------+ | Kevin McHugh - SW Engineer | mkmchu@fax.cs.mci.com | | MCI Telecommunications Corp. | (719) 535-5278 | +------------------------------+-------------------------+----------------+ | ALL RIGHTS RESERVED. | | This posting is copyright and may be used only for the purposes | | of professional study. Use of this posting in any commercial | | environment is explicity prohibited. This posting may only be | | reproduced for personal archival purposes. | +-------------------------------------------------------------------------+