Locally managed Tablespaces

[nw1234]

In locally managed tablespaces... when a table takes another extent... does any information get put into the sys tables? If so which one?

Which alter table (storage) commands are valid in a table that is in a locally managed tablespace?

Thanks!

[ligang]

U may check out the dba_segment and dba_extend which tells u the size of next extend and current extend

[rohitsn]

Hi,
In a locally managed tablespace Oracle will update the bitmap tables which is stored in each datafile which consitute that tablespace.So whenever it has allocate a new extent it doesnot have to go to the system tablespace to find out the next available extent.It will automatically take it from the bitmap table in the datafile.No doubt it has to write to system tables whenever a new extent is allocated or deallocated but the I/) to the system tablespace is reduced to a great deal.
It will put the information in dba_extents and dba_segements whenever an extent is allocated or deallocated.
When u create a table or alter a table in a locally managed tablespace u cannot specify the default storage clause,minimum extent or temporary.Oracle will allocate the next extent with the uniform size of n(where n is the uniform size which u specify while creating the locally managed tablespace).

CREATE TABLESPACE USERS DATAFILE 'c:\data\usersdata01.dbf' SIZE 10M
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 128K;

This statement creates a locally managed tablespace in which every extent is 128K.

In case of any help please be free to ask me at rohitsn@altavista.com

Regards,
Rohit Nirkhe,Oracle DBA,OCP 8i
rohitsn@altavista.com