Home
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.
Updating Statistics for ColumnsThe Table and Column Scope specification can also include the names of one or more columns for which you want statistical distributions calculated.

Updating Statistics for Columns

The Table and Column Scope specification can also include the names of one or more columns for which you want statistical distributions calculated.

In the following example, this statement calculates the distributions for three columns of the orders table:

UPDATE STATISTICS FOR TABLE orders (order_num, customer_num, ship_date);

If you include no column name in the FOR TABLE clause, then distributions are calculated for all columns of the specified table, using the LOW, MEDIUM, or HIGH mode and the number of bins implied by the specified or default Resolution clause percentage (for MEDIUM or HIGH mode) that you request.

See also Updating Statistics for Columns of User-Defined Types for UPDATE STATISTICS restrictions on columns that store UDTs.