SQLite : Pragma cache_spill = false not working

I was getting a "database locked" error while reading as I was executing long transaction. Since Cache_Spill is the reason for this exclusive lock, I wanted to avoid exclusive lock on the database . So I needed to set cache_spill = false.

But the following code seems not to be working.

iretval = sqlite3_exec(pSqlHandle,
            "PRAGMA cache_spill=false",ZERO,ZERO,ZERO);
    if(iretval != SQLITE_OK)
    {
        iretval = DB_QUERY_FAILED;
        goto db_close;
    }

I am not getting any error.But I am still getting the lock at the same position while reading.