The mi_qual_const_depends_outer() accessor function
The mi_qual_const_depends_outer() function indicates that an outer join provides the constant in a qualification.
Syntax
mi_boolean
mi_qual_const_depends_outer(MI_AM_QUAL_DESC *qualDesc)- qualDesc
- Points to the qualification descriptor.
Usage
If this mi_qual_const_depends_outer() evaluates to MI_TRUE, the join or subquery can produce a different constant value for each rescan.
Call mi_qual_const_depends_outer() in am_rescan. If your access method has no am_rescan purpose function, call mi_qual_const_depends_outer() in am_beginscan.
Return values
- MI_TRUE
- Indicates that the constant depends on an outer join.
- MI_FALSE
- Indicates that the constant remains the same on a rescan.