• Sreeharsha Ramanavarapu's avatar
    Bug #21143080: UPDATE ON VARCHAR AND TEXT COLUMNS PRODUCE · 888fabd6
    Sreeharsha Ramanavarapu authored
                   INCORRECT RESULTS
    
    Issue:
    -----
    Updating varchar and text fields in the same update
    statement can produce incorrect results. When a varchar
    field is assigned to the text field and the varchar field
    is then set to a different value, the text field's result
    contains the varchar field's new value.
    
    SOLUTION:
    ---------
    Currently the blob type does not allocate space for the
    string to be stored. Instead it contains a pointer to the
    varchar string. So when the varchar field is changed as
    part of the update statement, the value contained in the
    blob also changes.
    
    The fix would be to actually store the value by allocating
    space for the blob's string. We can avoid allocating this
    space when the varchar field is not being written into.
    888fabd6
update.result 15.5 KB