mi_boolean mi_scan_newquals(MI_AM_SCAN_DESC *scanDesc);
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.
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.