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

I ran a test similar to what your talking about, we evaluated wether changing a ( ID number ) to integer as opposed to a 9 char string. I saw no big performance difference in terms of inserting and retrieving the indexed data. This was for Informix 4.~ and informix 5.05 something. I don't have 7.0~ numbers yet. I have statistical numbers to show this. There was a slight performance increase for the integer representation, but I attributed that to the smaller record size and key sizes. The only other area that you will notice changes will be in space savings. 4 bytes as opposed to (16 bytes) * (X million records) * ( Y tables ) could be significant. Of course, your mileage may vary. John. _______________________________________________________________________________ From: Aaron D. Gross on Fri, Jan 26, 1996 1:11 PM Subject: What's the performance impact of changing data type of primary key from INTEGER to CHAR(16) To: informix-list@rmy.emory.edu There has been a debate where I work regarding the performance hit we might take by changing 16-character string. Logically, the change makes sense, from an applications point of view. However, we know that we will take a performance hit... we just don't know how to estimate this. Any recommendations for estimating the impact would be greatly appreciated. We anticipate the table will grow by approximately 2.5 million records a year. If it is a problem that will not have an immediate impact--that is, it would become a problem within a few years--this would be valuable to know... we could probably expect that hardware performance will double within 3-4 years, offsetting the loss due to the change. Thanks in advance. Email greatly appreciated.