mi_boolean
mi_qual_const_depends_hostvar(MI_AM_QUAL_DESC *qualDesc)
Call mi_qual_const_depends_hostvar() in the am_scancost purpose function to determine whether a qualification function contains a host variable but no explicit constant value.
Because the database server executes am_scancost before the application binds the host variable to a value, the qualification descriptor cannot provide a value in time to evaluate the cost of the scan.
If mi_qual_const_depends_hostvar() returns MI_TRUE, am_scancost can call mi_qual_setreopt(), which tells the database server to reoptimize before it executes the scan.
MI_TRUE indicates that a host variable provides values when the function executes. MI_FALSE indicates that the qualification descriptor supplies the constant value.
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