The regression test cases added in commits b2cbced9e et al depended in part
on the Russian timezone offset changes of Oct 2014. While this is of no
particular concern for a default Postgres build, it was possible for a
build using --with-system-tzdata to fail the tests if the system tzdata
database wasn't au courant. Bjorn Munch and Christoph Berg both complained
about this while packaging 9.4rc1, so we probably shouldn't insist on the
system tzdata being up-to-date. Instead, make an equivalent test using a
zone change that occurred in Venezuela in 2007. With this patch, the
regression tests should pass using any tzdata set from 2012 or later.
(I can't muster much sympathy for somebody using --with-system-tzdata
on a machine whose system tzdata is more than three years out-of-date.)
Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time. But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation. Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.
To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone. For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time. However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.
The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970. The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.
While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.
This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib. Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.
This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time. We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.
In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
America/Metlakatla hasn't been in the IANA database all that long, so
some installations might not have it. It does seem worthwhile to test
with a fractional-minute GMT offset, but we can get that from almost
any pre-1900 date; I chose Europe/Paris, whose LMT offset from Greenwich
should be pretty darn well established.
Also, assuming that Mars/Mons_Olympus will never be in the IANA database
seems less than future-proof, so let's use a more fanciful location for
the bad-zone-name check.
Per complaint from Christoph Berg.
Author: Pavel Stěhule, editorialized somewhat by Álvaro Herrera
Reviewed-by: Tomáš Vondra, Marko Tiikkaja
With input from Fabrízio de Royes Mello, Jim Nasby
noise words for the last twelve years, for compatibility with Berkeley-era
output formatting of the special INVALID values for those datatypes.
Considering that the datatypes themselves have been deprecated for awhile,
this is taking backwards compatibility a little far. Per gripe from Josh
Berkus.
cases. Recent buildfarm experience shows that it is sometimes possible
to execute several SQL commands in less time than the granularity of
Windows' not-very-high-resolution gettimeofday(), leading to a failure
because the tests expect the value of now() to change and it doesn't.
Also, it was recognized some time ago that the same area of the tests
could fail if local midnight passes between the insertion and the checking
of the values for 'yesterday', 'tomorrow', etc. Clean all this up per
ideas from myself and Greg Stark.
There remains a window for failure if the transaction block is entered
exactly at local midnight (so that 'now' and 'today' have the same value),
but that seems low-probability enough to live with.
Since the point of this change is mostly to eliminate buildfarm noise,
back-patch to all versions we are still actively testing.
this adds support for 64-bit tzdata files, which is needed to support DST
calculations beyond 2038. Add a regression test case to give some minimal
confidence that that really works.
Heikki Linnakangas
historically worked in some but not all cases, but as of 8.2 it failed for all
timezone formats. Fix, and add regression test cases to catch future
regressions in this area. Per gripe from Adam Witney.
to_timestamp():
- ID for day-of-week
- IDDD for day-of-year
This makes it possible to convert ISO week dates to and from text
fully represented in either week ('IYYY-IW-ID') or day-of-year
('IYYY-IDDD') format.
I have also added an 'isoyear' field for use with extract / date_part.
Brendan Jurd
input routines. Remove the former "DecodePosixTimezone" function in favor of
letting the zic code handle POSIX-style zone specs (see tzparse()). In
particular this means that "PST+3" now means the same as "-03", whereas it
used to mean "-11" --- the zone abbreviation is effectively just a noise word
in this syntax. Make sure that all named and POSIX-style zone names will be
parsed as a single token. Fix long-standing bogosities in printing and input
of fractional-hour timezone offsets (since the tzparse() code will accept
these, we'd better make 'em work). Also correct an error in the original
coding of the zic-zone-name patch: in "timestamp without time zone" input,
zone names are supposed to be allowed but ignored, but the coding was such
that the zone changed the interpretation anyway.
configuration files that can be altered by a DBA. The australian_timezones
GUC setting disappears, replaced by a timezone_abbreviations setting (set this
to 'Australia' to get the effect of australian_timezones). The list of zone
names defined by default has undergone a bit of cleanup, too. Documentation
still needs some work --- in particular, should we fix Table B-4, or just get
rid of it? Joachim Wieland, with some editorializing by moi.
literally.
Add GUC variables:
"escape_string_warning" - warn about backslashes in non-E strings
"escape_string_syntax" - supports E'' syntax?
"standard_compliant_strings" - treats backslashes literally in ''
Update code to use E'' when escapes are used.
support for 'week' within the date_trunc function.
Within the patch I added a couple of test cases and associated target
output, and changed the documentation to add 'week' appropriately.
Robert Creager
> > needed, and other people in the past asked about it too.
>
> It is in Oracle, but you aren't exactly on the spot. It should be
>
> IYYY - 4 digits ('2003')
> IYY - 3 digits ('003')
> IY - 2 digits ('03')
> I - 1 digit ('3')
Here is an updated patch that does that.
Kurt Roeckx
heuristic determination of day vs month in date/time input. Add the
ability to specify that input is interpreted as yy-mm-dd order (which
formerly worked, but only for yy greater than 31). DateStyle's input
component now has the preferred spellings DMY, MDY, or YMD; the older
keywords European and US are now aliases for the first two of these.
Per recent discussions on pgsql-general.
time zones.
SQL99 spec requires a default of zero (round to seconds) which is set
in gram.y as typmod is set in the parse tree. We *could* change to a
default of either 6 (for internal compatibility with previous versions)
or 2 (for external compatibility with previous versions).
Evaluate entries in pg_proc wrt the iscachable attribute for timestamp and
other date/time types. Try to recognize cases where side effects like the
current time zone setting may have an effect on results to decide whether
something is cachable or not.
Tom Lane
Alvaro Herrera
Bruce Momjian
Peter Eisentraut
Thomas G. Lockhart