DBC space.( How much perm space and spool space) should be allocated.


DBC space.( How much perm space and spool space) should be allocated.

Hi all,Regarding space(perm and spool space) allocations for system and user databases

Of the total system space which is initially owened by 'DBC'. How much could it be utilized? ( Perm and spool space)

As we use Perm to store the data and spool space for calculations. How much does DBC need as perm space and spool space.

I see there is spool reserve in the system is it used by dbc or by any other resource like PDCR? Because PDCR and dbase or like any have their own spool allocated except some or most of the databases which are not system(default) databases. If a database is not allocated a spool space? does it matter; as any query will use the spool space from user allocated for intermediate calculation or any. If a database is given a spool space; how is it useful to the database( as all the volatile and global temporary tables are created under user spool space).

Thanks in advance.

Teradata Employee

Re: DBC space.( How much perm space and spool space) should be allocated.

DBC PermSpace includes the data dictionary, log tables (e.g. ResUsage, DBQL) and should also be large enough to accommodate in-flight "Transient Journal" space. How much is needed will depend on what data you log and how long you keep it in DBC, as well as how much uncommitted data you have at any point in time. Running out of PermSpace in database DBC is something you want to avoid.

Note that there is a difference between space limits and space usage. Any cylinders that are not already in use can be used for Spool or Temp space. Defining an "empty" SpoolReserve database is one way to try to ensure some space remains free for this purpose.

The only thing that a spool space limit does for a Database is to set a default / max value for any new users defined under that Database. Note that spool space (including Volatile tables) is only "allocated" for a session; the total allocated is compared with the User limit (or Profile limit instead, if assigned). Similarly for Temporary space (used for Global Temporary tables).