Re: Update on Supporting Encryption in Postgresql

Our basic claim is to be able to do most of the encryption while we are
reading the page. That is the reason I need the threads. Any suggestion
about the threads are welcome. Thanks.
Murat

Alvaro Herrera wrote:
> On Fri, Sep 10, 2004 at 11:52:26AM -0500, Murat Kantarcioglu wrote:
>
>
>>Can you suggest me a solution to how to do
>>this on Postgresql backend?
>>
>>I am asssuming that somewhere in the code, you are calling a function like
>> getPage(Page_id)
>>to retrieve the page(I am trying to change backend)
>
>
> Probably the code you want to modify is in src/backend/storage/smgr.
> Maybe you want to add a different storage manager (they are pluggable,
> sort of).
>
>
>> getPage(Page_id)
>> {
>> ctr=Hash_Table(Page_id) //return somevalue needed for deccryption
>> Thread_Read(Page_id) // will call the original read code
>> Thread_Encryption.start(ctr, length);
>> when both threads are done finish the encryption
>> }
>
>
> I think it would need extensive, painful and unwelcome modifications to
> use threads to do the job. You could just as well do it sequentially,
> like in
>
> encryptedPage = getPage(page_id);
> clearPage = unencrypt(encryptedPage);
> return clearPage;
>
>
> And the reverse for storage. This may only need modifications to
> mdread() and mdwrite() ... unless your encryption scheme returns a
> different length than the original.
>