The mi_scan_newquals() accessor function
The mi_scan_newquals() function indicates whether the qualification descriptor includes changes between multiple scans for the same query statement.
Syntax
mi_boolean mi_scan_newquals(MI_AM_SCAN_DESC *scanDesc);- scanDesc
- Points to the scan descriptor.
Usage
This function pertains to multiple-scan queries, such as a join or subquery. If the access method provides a function for the am_rescan purpose, that rescan function calls mi_scan_newquals().
If this function returns MI_TRUE, retrieve information from the qualification descriptor and obtain function descriptors. If it returns MI_FALSE, retrieve state information that the previous scan stored in user data.
Return values
- MI_TRUE
- Indicates that the qualifications have changed since the start of the scan (am_beginscan).
- MI_FALSE
- Indicates that the qualifications have not changed.