Example of dbschema output showing distribution information
The dbschema output can show the data distributions that have been created for the specified table and the date when the UPDATE STATISTICS statement that generated the distributions ran.
The follow example of dbschema output shows distribution information.
Distribution for cathl.invoices.invoice_num
High Mode, 10.000000 Resolution
--- DISTRIBUTION ---
( 5)
1: ( 16, 7, 11)
2: ( 16, 6, 17)
3: ( 16, 8, 25)
4: ( 16, 8, 38)
5: ( 16, 7, 52)
6: ( 16, 8, 73)
7: ( 16, 12, 95)
8: ( 16, 12, 139)
9: ( 16, 11, 182)
10: ( 10, 5, 200)
--- OVERFLOW ---
1: ( 5, 56)
2: ( 6, 63)
}Description of the distribution information in the example
The first part of the sample dbschema output
describes which data distributions have been created for the specified
table. The name of the table is stated in the following example:
Distribution for cathl.invoices.invoice_numThe
output is for the invoices table, which is owned by user cathl.
This data distribution describes the column invoice_num. If
a table has distributions that are built on more than one column, dbschema lists
the distributions for each column separately.
The dbschema output also shows the date when the UPDATE STATISTICS statement that generated the distributions ran. You can use this date to tell how outdated your distributions are.
The last line of the description portion
of the output describes the mode (MEDIUM or HIGH) in which the distributions
were created, and the resolution. If you create the distributions
with medium mode, the confidence of the sample is also listed. For
example, if the UPDATE STATISTICS statement runs in HIGH mode with
a resolution of
10, the last line appears as the
following example shows: High Mode, 10.000000 Resolution