openstack/swift
Code Issues Proposed changes

Add a note about the cost of COPY for setting metadata

Browse Source 
The pointer to using COPY to the same object as a mechanism to set only
a subset of the metadata, it does not mention that doing so results in
a full copy of the object in question on the backend.

Add a note so it's clear that there is a tradeoff involved.

Change-Id: I0c20a4909a6c3ff672f753d26cb9fb2f5f33d1f4
This commit is contained in:
Monty Taylor 2018-01-16 11:32:12 -06:00
parent 909e371515
commit bc6fb89951
No known key found for this signature in database
GPG Key ID: 7BAE94BC7141A594
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
api-ref/source/storage-object-services.inc
View File

@ -650,6 +650,12 @@ metadata on the request to copy the object, either PUT or COPY ,
the metadata overwrites any conflicting keys on the target (new)
object.
.. note::
While using COPY instead of POST allows sending only a subset of
the metadata, it carries the cost of reading and rewriting the entire
contents of the object.
A POST request deletes any existing custom metadata that you added
with a previous PUT or POST request. Consequently, you must specify
all custom metadata in the request. However, system metadata is