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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: SyntaxThe HCL OneDB™ Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the HCL OneDB™ dialect of the SQL language.
SQL statementsThis chapter describes the syntax and semantics of SQL statements that are recognized by HCL OneDB™.
UPDATE STATISTICS statementUse the UPDATE STATISTICS statement to update system catalog information that the query optimizer uses for operations on objects in the local database. The UPDATE STATISTICS statement is an extension to the ANSI/ISO standard for SQL.
Updating Statistics for TablesAlthough a change to the database might make information in the systables, syscolumns, sysindices, sysfragments, sysdistrib, and sysfragdist system catalog tables obsolete, the database server does not automatically update those tables after most SQL statements.
Using the FOR TABLE ONLY Keywords

Using the FOR TABLE ONLY Keywords

Use the FOR TABLE ONLY keywords to collect data for a single table within a hierarchy of typed tables. If you do not include the ONLY keyword immediately after FOR TABLE when the specified table has subtables, HCL OneDB™ creates distributions for that table and also for every subtable under it in the hierarchy.

For example, suppose your database has the typed table hierarchy that appears in Example of Typed Table Hierarchy, 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.

begin figure description - This figure is described in the surrounding text - end figure description — Figure 1: 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);

If you specify FOR TABLE ONLY, as in this example, the identifier of the table (or owner.table) must be enclosed between parentheses.

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.