walk on one column in a table

[Fong Tsui]

When doing snmpwalk on a single column in a table which has 50 columns, I found it queries data for all 50 columns and displays the one needed.  It’s wasting a lot by getting data not needed. Even walking an empty table; it goes through all columns in that table.   I am using oid-api (v5.0.9 on linux) var_XXX (struct variable *vp,                         oid * name,                         size_t * length,                         int exact,                         size_t * var_len, WriteMethod ** write_method)   Is there any way that I can make it skip unnecessary columns? Where in the code to decide when to stop walk?   Thanks,   FT