On 2020/04/15 5:33, Andrew Dunstan wrote:
On 4/14/20 4:09 PM, Alvaro Herrera wrote:
On 2020-Apr-14, Andrew Dunstan wrote:
OK, but I think if we're putting a timestamp string in ISO-8601 format
in the manifest it should be in UTC / Zulu time, precisely to avoid
these issues. If that's too much trouble then yes an epoch time will
probably do.
The timestamp is always specified and always UTC (except the code calls
it GMT).
+ /*
+ * Convert last modification time to a string and append it to the
+ * manifest. Since it's not clear what time zone to use and since time
+ * zone definitions can change, possibly causing confusion, use GMT
+ * always.
+ */
+ appendStringInfoString(&buf, "\"Last-Modified\": \"");
+ enlargeStringInfo(&buf, 128);
+ buf.len += pg_strftime(&buf.data[buf.len], 128, "%Y-%m-%d %H:%M:%S %Z",
+ pg_gmtime(&mtime));
+ appendStringInfoString(&buf, "\"");
I was merely saying that it's trivial to make this iso-8601 compliant as
buf.len += pg_strftime(&buf.data[buf.len], 128, "%Y-%m-%dT%H:%M:%SZ",
ie. omit the "GMT" string and replace it with a literal Z, and remove
the space and replace it with a T.
I have one question related to this; Why don't we use log_timezone,
like backup_label? log_timezone is used for "START TIME" field in
backup_label. Sorry if this was already discussed.
/* Use the log timezone here, not the session timezone */
stamp_time = (pg_time_t) time(NULL);
pg_strftime(strfbuf, sizeof(strfbuf),
"%Y-%m-%d %H:%M:%S %Z",
pg_localtime(&stamp_time,
log_timezone));
OTOH, *if* we want to use the same timezone for backup-related files because
backup can be used in different environements and timezone setting
may be different there or for other reasons, backup_label also should use
GMT or something for the sake of consistency?
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
