Re: unreferenced primary keys: garbage collection

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От Jan Wieck
Тема Re: unreferenced primary keys: garbage collection
Дата
Msg-id 200101202213.RAA12172@jupiter.jw.home
обсуждение исходный текст
Ответ на unreferenced primary keys: garbage collection  (Forest Wilkinson <fspam@home.com>)
Ответы Re: unreferenced primary keys: garbage collection
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Forest Wilkinson wrote:
> I have a database in which five separate tables may (or may not) reference
> any given row in a table of postal addresses.  I am using the primary /
> foreign key support in postgres 7 to represent these references.
>
> My problem is that, any time a reference is removed (either by deleting or
> updating a row in one of the five referencing tables), no garbage
> collection is being performed on the address table.  That is, when the
> last reference to an address record goes away, the record is not removed
> from the address table.  Over time, my database will fill up with
> abandoned address records.
   While  this  behaviour  makes  sense  in  your case, it's not   subject  to  referential  integrity  constraints.
You could   arrange  for  it with custom trigger procedures, checking all   the five tables on DELETE or UPDATE on one
ofthem.
 
   I'll make up a little example and post it  the  other  day  -   need  to  take  a  nap  now and tomorrow will be one
ofthese   30-hour days (from MET to  EST),  so  don't  expect  anything   before Monday afternoon (EST).
 


Jan

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