thanks for your reply,
with 'my yable has read-only records' i mean that existing record cannot be updated or deleted, the only write operation allowed on that table is to add new records but this constraint is only implemented at client-application level (ie using another client application as isql tool an user can update a row of that table).

i don't want to use trigger on INSERT (in my previous post i tell wrongly on update) becouse the behaviour of my application will be samething as
- the service insert a block of same rows (for example 10k records)
- for an interval of time from same seconds to same minutes (it is not a fixed interval) the table will not change
- the service insert another block of rows...
.....

but what i want is to recalculate the view/second table only when the last row of the block is inserted (or equivalent when the transaction where them are isnrted has been committed).

i hope that there's samething as view cached with the cache expiration wich depends on the modification of the table wich contains raw data, but your suggestion to use a secondary physical table wich will be updated by my service after the rows insertion is ok too (and probably it will give me a better/simpler application).

thanks for the helps