Luckily, after had a meeting with Cathy (the grad student we've been working with) on Thursday, we decided to set any columns we are not sure to size 255. And later we'll use MySQL to check the size of each column.
SELECT MAX, MIN(LENGTH(column name));
This command will help us to find out the size and null situation.
We finally installed MySQL. It was harder than we thought. Althougth the instruction on the MySQL homepage on the web is pretty helpful, it still took us a long time to set it up right. Another difficulty we encountered was we are not sure if MySQL and Tomcat (webserver) work together. We found out that MySQL and Tomcat do work together, but we don't know if they need to be on the same machine because we installed MySQL on ENDER(one of the unix machines) since ENDER has more space, but TOMCAT is on GALT(another unix machine). We are not sure if this will cause trouble. If it cause trouble later, I suppose we'll move Tomcat to ENDER as well. But we are not sure yet. We'll find out soon.
Since we installed MySQL and finished (kind of) our load script of UMLS files, we tested if they work okay and so it's working fine so far. But I have a little log in problem with MySQL. That is, MySQL is installed on Alice machine and under her name, so every time when I try to log in, she has to be in, otherwise I won't be able to log in. So we are also working on the access issue as well.