The INSPECT command inspects a database
for architectural integrity, checking the pages of the database for
page consistency. The INSPECT command checks that
the structures of table objects and structures of table spaces are
valid. Cross object validation conducts an online index to data consistency
check. The db2dart command examines databases for
architectural correctness and reports any encountered errors.
The INSPECT command is similar to the db2dart command
in that it allows you to check databases, table spaces, and tables.
A significant difference between the two commands is that the database
needs to be deactivated before you run db2dart,
whereas INSPECT requires a database connection and can be run while
there are simultaneous active connections to the database.
If you do not deactivate the database, db2dart will
yield unreliable results.
The following tables list the differences between the tests that
are performed by the db2dart and INSPECT commands.
Table 1. Feature comparison of db2dart and INSPECT for table
spaces
| Tests performed |
db2dart |
INSPECT |
| SMS table spaces |
| Check table space files |
YES |
NO |
| Validate contents of internal page header fields |
YES |
YES |
| DMS table spaces |
| Check for extent maps pointed at by more than
one object |
YES |
NO |
| Check every extent map page for consistency
bit errors |
NO |
YES |
| Check every space map page for consistency bit
errors |
NO |
YES |
| Validate contents of internal page header fields |
YES |
YES |
| Verify that extent maps agree with table space
maps |
YES |
NO |
Table 2. Feature comparison of db2dart and INSPECT for data
objects
| Tests performed |
db2dart |
INSPECT |
| Check data objects for consistency bit errors |
YES |
YES |
| Check the contents of special control rows |
YES |
NO |
| Check the length and position of variable length
columns |
YES |
NO |
| Check the LONG VARCHAR, LONG VARGRAPHIC, and
large object (LOB) descriptors in table rows |
YES |
NO |
| Check the summary total pages, used pages and
free space percentage |
NO |
YES |
| Validate contents of internal page header fields |
YES |
YES |
| Verify each row record type and its length |
YES |
YES |
| Verify that rows are not overlapping |
YES |
YES |
Table 3. Feature comparison of db2dart and
INSPECT for index objects
| Tests performed |
db2dart |
INSPECT |
| Check for consistency bit errors |
YES |
YES |
| Check the location and length of the index key
and whether there is overlapping |
YES |
YES |
| Check the ordering of keys in the index |
YES |
NO |
| Determine the summary total pages and used pages |
NO |
YES |
| Validate contents of internal page header fields |
YES |
YES |
| Verify the uniqueness of unique keys |
YES |
NO |
| Check for the existence of the data row for
a given index entry |
NO |
YES |
| Verify each key to a data value |
NO |
YES |
| Verify the hash value for key parts with RANDOM
ordering |
YES |
YES (when the INDEXDATA option of INSPECT is
used) |
Table 4. Feature comparison of db2dart and INSPECT for block
map objects
| Tests performed |
db2dart |
INSPECT |
| Check for consistency bit errors |
YES |
YES |
| Determine the summary total pages and used pages |
NO |
YES |
| Validate contents of internal page header fields |
YES |
YES |
Table 5. Feature comparison of db2dart and INSPECT for long
field and LOB objects
| Tests performed |
db2dart |
INSPECT |
| Check the allocation structures |
YES |
YES |
| Determine the summary total pages and used pages
(for LOB objects only) |
NO |
YES |
In addition, the following actions can be performed using the
db2dart command:
- Format and dump data pages
- Format and dump index pages
- Format data rows to delimited ASCII
- Mark an index invalid
The
INSPECT command cannot be used to perform
those actions.