HP ProLiant DL980 G7 Server - Manual (Page 47)

Trace flag 2562
By default, the DBCC CHECKDB command tries to minimize the amount of tempdb resources
required to check the entire database. The command does this by breaking up the database into
batches. This reduces the number of indexes or "facts" that it generates. Trace flag 2562 implements
the following changes:
•
Forces the DBCC CHECKDB command to run all processing in a single batch regardless of the
number of indexes in the database.
•
Improves the internal process for determining which pages to read from the database. This
reduces contention on the DBCC_MULTIOBJECT_SCANNER latch, helping avoid such errors
as:
Timeout occurred while waiting for latch: class ‘DBCC_MULTIOBJECT_SCANNER’.
One effect of using this trace flag is that the space requirements for tempdb may increase. The
tempdb may grow to as much as 5% or more of the user database that is being processed by the
DBCC CHECKDB
command. Therefore, to avoid automatic growth when you use this trace flag,
which may slow down the performance of the DBCC CHECKDB command, HP recommends that
you pre-size tempdb to at least 5% of your database size.
System page: Viewing and enabling system optimization recommendations
The System page displays information about add-on PCI controllers; settings of Software Discovery
(
“Configuring and initiating Software Discovery” (page 48) ); and status of system software, drivers,
and firmware versions. The page shows the result of the software discovery process. Figure 41
(page 47) shows an example of a System page.
Figure 41 System page
PCI Controller Information
This section of the page enumerates all of the system's add-on PCI cards. It also indicates when
PCI cards are inserted in slots that are incapable of utilizing their maximum capabilities. If
better-suited slots are available, HP ESO recommends them by slot number.
Optimizations pages 47