Varchar does it cause data file to continously grow

[Eric Hernandez]

Hi I am using the innodb_plugin 1.0.9 (MySQL 5.1.48)

If I use varchar does innodb reclaim space in the innodb data file.
Or can it only do this with char?

My concern is that if I use varchar i will be saving space per row but my ibd file will grow indifinetely until i rebuild table. On the other hand I use char my table will be bigger but i can re-use table space and this might make the overall table smaller.

Thanks

-Eric