On 24 Apr 2016, at 1:51pm, Carlos <milon at terra.com.br> wrote: > But, with very fast CPUs and RAM memory buffers for the directory entries in > the disks, > the variable length records would probably result in gain for much less I/O > for the data.
Agreed. Which is one reason why fixed-length string columns are less important and less used now. When the bottleneck is the speed of the backing store, storing fewer characters can mean the difference between having to write one sector or two. Another reason is that we use Unicode not ASCII/SIXBIT/EBCDIC, and in Unicode different characters take different numbers of bytes. So even if you're storing a fixed number of bytes the convenience of always knowing exactly how many characters to display no longer exists. Simon.
