>you suggest to turn tables and indexes into read-only state.
>is it possible to update a read-only tables ?

Not directly. You'd have to put updates in a temporary table on the "server" and then update the primary from there. Safer, but not sure if it's worth the trouble. That depends how soon you need the updates to be viewable.

I always advise people at the outset, though, to divide all app files into 2 main categories & directories: one group that needs updating, and another group that can be read-only or have nightly scheduled updates. The 2nd group is always safer, so you put as many files in it as possible. DBCs and related files (DCT, DCX) usually go in a read-only directory, and that helps DBC corruption immensely.

What I generally do is break up large updateable tables into parts, that helps minimze damage potential. You group the users, and give write-access to only certain tables. All other users have readonly access. You can join them with SQL for viewing.

Also as someone suggested, you can limit damage by using cursors/views/buffering/transactions. After all, the real concern is data corruption, not indexes. Index corruption is only a nuisance, IMO.