Drupal permission table If u have seen drupal permission table, that is like

structure 1

pid rid    perm                   tid
1    1   view f1, edit f2          0
2    2   view f1                   0


what is good with  structure1?

why drupal doesn't use this structure?

table1

    fid      name
    1      view f1
    2      edit f2

table2

pid  rid  fid
1     1    1
2     1    2
3     2    1
Table 1 matches how it is in Drupal 6, table matches more or less how it is in Drupal 7.

So to answer your Question, the newest Drupal does indeed use a schema close to what you proposed.