Cisco Headend Digital Broadband Delivery System Installation Guide
Database Fragmentation, Database Used Capacity, and the Doctor Report
4020695 Rev C
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Database Fragmentation, Database Used Capacity,
and the Doctor Report
and the Doctor Report
System operators who use the dncsDbData utility to defragment their database may
notice that the Doctor Report shows that the percentage of the database in use is
significantly higher after defragmenting the database than it was before
defragmenting the database. The reason for the significant increase in the percentage
of the database in use is that the dncsDbData utility associated with version 1.1 and
later of DNCS Utilities preallocates a large amount of database space to the emm
table when the table is reloaded during the defragmentation process. When the
Doctor Report then analyzes the condition of the database, the Doctor Report
considers the space allocated to the emm table to be in use, even though it may
initially be empty.
notice that the Doctor Report shows that the percentage of the database in use is
significantly higher after defragmenting the database than it was before
defragmenting the database. The reason for the significant increase in the percentage
of the database in use is that the dncsDbData utility associated with version 1.1 and
later of DNCS Utilities preallocates a large amount of database space to the emm
table when the table is reloaded during the defragmentation process. When the
Doctor Report then analyzes the condition of the database, the Doctor Report
considers the space allocated to the emm table to be in use, even though it may
initially be empty.
The Doctor Report Output Before Defragmenting the Database
The Monitor and Eliminate Database Fragmentation (on page 53) section lists
several tables in the DNCS and the Application Server databases that system
operators should monitor for the presence of fragmentation. System operators use
the Doctor Report to monitor these tables.
several tables in the DNCS and the Application Server databases that system
operators should monitor for the presence of fragmentation. System operators use
the Doctor Report to monitor these tables.
If any of these tables contains ten or more extents, system operators are advised to
use the dncsDbData utility to unload and reload the database. Under the reload
process, related data is loaded into contiguous locations in the database, and the
fragmentation is eliminated.
use the dncsDbData utility to unload and reload the database. Under the reload
process, related data is loaded into contiguous locations in the database, and the
fragmentation is eliminated.
Note: The number of table extents refers to the number of times a specific table is
fragmented across the hard drive.
fragmented across the hard drive.
Refer to Example of a Fragmented Database (on page 74) for an example of the
Doctor Report output showing a fragmented database.
Doctor Report output showing a fragmented database.