Why all the variable stuff?

Texis stands for Text Information Server, and text databases are really different in nature to the content of most standard databases. Have a look at the word processing files that are on your machine. The vast majority are probably relatively small, but then there's an occasional whopper. The same is true for the content of most documents: their size and content are extremely variable.

Texis is optimized for two things: Query time and variable sized data.