xHarbour Reference Documentation > Command Reference

SET OPTIMIZE

Toggles filter optimization with indexed databases.

Syntax

SET OPTIMIZE ON | off | (<lToggle>)

Arguments

ON | off | (<lOnOff>)

This option toggles the filter optimization for database navigation in the current work area. The initial value of this setting is defined by the RDD used to open database ans index files. The value ON or .T. (true) enables the optimization, the value OFF or .F. (false) disables it. Note that when specifiying <lOnOff> as a logical expression, it must be enclosed in parentheses.

Description

The SET OPTIMIZE command determines whether or not to optimize filters in the current work area. Optimization is based on index expressions of indexes open in the current work area. When a filter condition matches with an index expression, the RDD, such as DBFCDX, compares values stored in the index rather than the database. This leads to an enhanced performance since less disk I/O is required during database navigation.

Info

See also:	Set(), SET FILTER, SET INDEX
Category:	Database commands , SET commands
Source:	rtl\set.c
LIB:	xhb.lib
DLL:	xhbdll.dll