Re: about compression

You are right about that. I have thought about doing that but decided against that due to two reasons. 1. I have to use additional time when I look up the information. 2. most of my records, even when I have it, don't fill up all 300 chars, say average 100, therefore I'd still waste a good percentage of the space. However, you are still right though, under the right circumstances it'd be a viable solution. thanks a lot. yan Vic Glass wrote: > I realize that you're question is about data compression, but an alternate > solution to using VARCHAR instead of CHAR is change the design of the table > in question. For example: > > Before: > create table emp > ( > emp_id serial > lname char(25), > fname char(25), > comment char(300), > ... > ... > primary key (emp_id) > )> > After: > create table emp > ( > emp_id serial > lname char(25), > fname char(25), > ... > ... > primary key (emp_id) > )> > create table emp_comment > ( > emp_id integer, > comment char(300), > foreign key (emp_id) references emp > )> > In this case, data only *exists* when it is needed. > > Yan Zhu wrote: > > > hi all: > > I have a field in a table which needs to be 300 long. However, only > > 5% of all records (half a million of them) has this field filled with > > actual text. My question is, does informix automatically compress the > > empty space or do I have to do something to make it compress the wasted > > space? I don't want to use 300 chars for each field while I don't use > > most of them. > > > > thanks > > yan