Chapter 15


A1:

The memory tracker and memory visualizer tools display DB2's memory usage at the instance, database, and agent levels.

A2:

The DATABASE_MEMORY configuration parameter allocates more shared memory than actually used to allow for the increase of the buffer pools, lock list, and so on, or for the creation of new buffer pools.

A3:

The package cache allows for the sharing and reuse of packages between applications.

A4:

The shared sort heap threshold is a hard limit for the concurrent amount of memory that can be used for shared sorts.

A5:

The log buffer is flushed to disk:

  • When it is filled

  • When MINCOMMIT commits occur

  • Or every one second

depending on which occurs first. Therefore, the longest time period between flushes of the log buffer is one second.

A6:

If the DATABASE_MEMORY configuration parameter is set to AUTOMATIC, you can connect to the database and at any time issue the GET DB CFG FOR dbname SHOW DETAIL command. It will show AUTOMATIC(nnnnnn), and nnnnnn will be the actual amount of used memory.

A7:

The largest size you can set for the client requester I/O block is 64KB.

A8:

The instance-level (database manager) shared memory is allocated when you run the db2start command.

A9:

The database shared memory is allocated when the database is activated or when the first connection to the database is made.

A10:

The Fast Communications Manager (FCM) buffers are used for inter-partition communication.

A11:

E. There will be the IBMDEFAULTBP, plus the four hidden buffer pools for a total of five buffer pools.

A12:

A. Application group shared memory is used for partitioned databases, databases using intra-partition parallelism, and when the connection concentrator is enabled.

A13:

D. The statistics heap is allocated in agent private memory.

A14:

A. The application group shared heap is calculated by multiplying the application group memory size by the percentage of memory for the application control heap, and therefore equals 10,000 x 30% or 3,000 pages.

A15:

C. Each group can hold 30,000/512 or 58 applications. Therefore, you will need 6 groups to hold the 300 applications.

A16:

C. Since 2000 / 256 = 7.81, there can be a maximum of 7 concurrent shred sorts within this database.

A17:

E. DB2 does not limit the number of concurrent private sorts in memory; it reduces the sort heap allocated once the sort heap threshold is reached, so there is no limit.

A18:

D. The buffer pools are database specific, and therefore are not part of the database manager shared memory.

A19:

D. Since the 10,000 16K pages would use an additional 40,000 4K pages, the minimum size for the shared memory would be 115,264 pages, but of the options given, you would need to set the database memory to 125,000 pages for the CREATE BUFFERPOOL statement to be successful.

A20:

A. There are no applications connected to the database.



Understanding DB2(R. Learning Visually with Examples)
Understanding DB2: Learning Visually with Examples (2nd Edition)
ISBN: 0131580183
EAN: 2147483647
Year: 2004
Pages: 313

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