Re: The extent about tablespace
Date: 1996/07/01
Message-ID: <DtvKrn.2yu_at_news.hawaii.edu>#1/1
Horse,
The short answer is: Tablespaces have no extents.
In Oracle's SQL reference manual, under "create tablespace", there's an example:
create tablespace tabspace_2
datafile 'diska:tabspace_file2.dat' size 20m
default storage (initial 10k next 50k
minextents 1 maxextents 999 pctincrease 10)
The tablespace is given control over one or more datafiles (called 'tabspace_file2.dat' of size 20 MB in the above example).
The tablespace itself has no extents (any tables declared to reside in tabspace_2, above, with no storage parameters specified will take on the default storage values).
Incidently, for tables, extents do not 'wrap around'. You will get a storage violation when you attempt to go beyond the declared maxextents value or hit the limit on the permissible maximum extents possible (depending on your block size) or reach the maximum number of extents possible in datafiles allocated for the tablespace or ... , whichever comes first.
The initial extent size is what you start with. Each time you need more space beyond what's available in your current extent, the system will grant you the next extent using the the storage parameters. The total size is:
initial extent + next + next*(1+pctincrease) +
+next*(1+pctincrease)*(1+pctincrease) + [up to maxextents]
aloha
dolphin
HORSE <DOG_at_CAT.CAT.CAT> wrote:
>Can someone give me some clue about how to determine the size of
>tablespace extent. Do you also conside extent wrap or not. I know
>how to calculate the table's, but not tablespace. Also If there are
>three tables(1M, 2M, 3M) going to store on this tablespace. What's
>the initial extent size for. Thanks,
Received on Mon Jul 01 1996 - 00:00:00 CEST