How can I estimate/calculate the space required in SHAREPLEX tablespace for Shareplex_LOBMAP table during activation?
Shareplex _lobmap table is populated at activation.
The way to estimate this value for a table that has LOB columns
:
(number of LOB columns in table) * (number of rows) * (21 * 2) + 18.
An aggregation of the application of this formula across _all_ tables should yield the number you seek.
The 21 * 2 + 18 is based on the structure of the shareplex_lobmap table:
SQL> desc shareplex_lobmap
Name Type
--------------------- --------------
TABLEOBJ NUMBER -- max size: 21 bytes
LOBID NUMBER -- ditto
RID ROWID -- size: 18 bytes
This does not factor in the space required for indexes.
