If you do not specify LOAD RESUME
YES, you can use the STATISTICS keyword to gather inline statistics.
In most cases, using the STATISTICS keyword eliminates the need to
run RUNSTATS after loading a table space.
However, if you
perform a LOAD PART operation, you should run RUNSTATS INDEX on the
nonpartitioned secondary indexes to update the catalog data about
these indexes.
Procedure
To collect statistics while loading a table:
- Use the STATISTICS option to collect statistics so that
the Db2 catalog
statistics contain information about the newly loaded data:
| Option |
Description |
|---|
| Collecting inline statistics for discarded rows |
If you specify the DISCARDDN
option when you collect inline statics and a row is found with check constraint errors or conversion
errors, the row is not loaded into the table. However, the LOAD utility collects inline statistics
before it identifies the rows to discard. As a general rule, if the number of discarded rows is
larger than 20 percent of the total number of rows in the table, , run the RUNSTATS utility
separately on the table after running LOAD. |
| Collecting inline statistics for data partitioned secondary
indexes |
To collect inline statistics on data partitioned secondary
indexes, you must allocate sort work data sets. |
If you perform a LOAD operation on a base table that contains an XML column, Db2 does not collect inline statistics for the
related XML table space or its indexes.
Recording these new statistics enables Db2 to select
SQL paths with accurate information.
-
Rebind any application plans that depend on the
loaded tables to update the path selection of any embedded SQL statements.
What to do next
To collect statistics on the loaded table, you
might need to invoke the RUNSTATS utility after the LOAD utility processing has completed.