Using the ONLY Keyword (IDS)

Use the ONLY keyword to collect data for one table in a hierarchy of typed tables. If you do not specify the ONLY keyword and the table that you specify has subtables, the database server creates distributions for that table and every table under it in the hierarchy.

For example, assume your database has the typed table hierarchy that appears in Figure 2, which shows a supertable named employee that has a subtable named sales_rep. The sales_rep table, in turn, has a subtable named us_sales_rep.

Figure 2. Example of Typed Table Hierarchy

When the following statement executes, the database server generates statistics on both the sales_rep and us_sales_rep tables:

UPDATE STATISTICS FOR TABLE sales_rep

In contrast, the following example generates statistical data for each column in table sales_rep but does not act on tables employee or us_sales_rep:

UPDATE STATISTICS FOR TABLE ONLY (sales_rep)

Because neither of the previous examples specified the level at which to update the statistical data, the database server uses the LOW mode by default.