I'm also puzzled by the following explanation from the Tuning Guide:
Selectivity and cardinality statistics
Working with cardinality statistics
When cardinality statistics are automatically updated
"For other operations, Derby automatically updates statistics
for the table and all indexes on the table if they are already exist.
Those operations are:
* (all indexes) When you execute SYSCS_UTIL.SYSCS_COMPRESS_TABLE.
* (index only) When you drop a column that is part of a table's
index; the statistics for the affected index are dropped, and statistics
for the other indexes on the table are updated.
"
What does the second bullet mean? Derby doesn't let you drop a column
from a table right now.
Thanks,
-Rick
