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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.
Automated Table Statistics Maintenance

Automated Table Statistics Maintenance

To simplify the complex and repetitive task of the DBA in maintaining current table statistics from which the query plan optimizer can design efficient query plans, HCL OneDB™ provides a table statistics maintenance system, called Auto Update Statistics (AUS). This can automate the identification of tables whose statistics are stale, and can automate the construction and execution of the corresponding UPDATE STATISTICS statements to recalculate their column distributions. The AUS system is provided with built-in criteria for when table statistics should be updated, but the DBA can modify these criteria to reflect current requirements and workloads.

For more information, see the description of the Auto Update Statistics maintenance system in the HCL OneDB Performance Guide. See also the description of the Scheduler, which the DBA can use to specify the policies, resources, and frequency with which the AUS system recalculates table statistics, in the HCL OneDB Administrator's Guide.