The UPDATE STATISTICS statement

The syntax of UPDATE STATISTICS is the same for UDTs as for built-in data types. Because the data distributions provide the optimizer with equivalent statistics, the database server does not calculate colmin and colmax for UDTs.

The statcollect() function executes once for every row that the database server scans during UPDATE STATISTICS. The number of rows that the database server scans depends on the mode and the confidence level. Executing UPDATE STATISTICS in HIGH mode causes the database server to scan all rows in the table. In MEDIUM mode the database server chooses the number of rows to scan based on the confidence level. The higher the confidence level, the higher the number of rows that the database server scans. For general information about UPDATE STATISTICS, refer to the HCL OneDB™ Guide to SQL: Syntax.

The statistics that the database server collects might require a smart large object for storage. The configuration parameter SBSSPACENAME specifies an sbspace for storing this information. If SBSSPACENAME is not set, the database server might not be able to collect the specified statistics.