This reverts commit f41e56c76e.
The build farm client would run the pg_upgrade tests twice, once as part
of the existing pg_upgrade check run and once as part of picking up all
TAP tests by looking for "t" directories. Since the pg_upgrade tests
are pretty slow, we will need a better solution or possibly a build farm
client change before we can proceed with this.
For performance reasons a larger segment size than the default 16MB
can be useful. A larger segment size has two main benefits: Firstly,
in setups using archiving, it makes it easier to write scripts that
can keep up with higher amounts of WAL, secondly, the WAL has to be
written and synced to disk less frequently.
But at the same time large segment size are disadvantageous for
smaller databases. So far the segment size had to be configured at
compile time, often making it unrealistic to choose one fitting to a
particularly load. Therefore change it to a initdb time setting.
This includes a breaking changes to the xlogreader.h API, which now
requires the current segment size to be configured. For that and
similar reasons a number of binaries had to be taught how to recognize
the current segment size.
Author: Beena Emerson, editorialized by Andres Freund
Reviewed-By: Andres Freund, David Steele, Kuntal Ghosh, Michael
Paquier, Peter Eisentraut, Robert Hass, Tushar Ahuja
Discussion: https://postgr.es/m/CAOG9ApEAcQ--1ieKbhFzXSQPw_YLmepaa4hNdnY5+ZULpt81Mw@mail.gmail.com
The plan is to convert the current pg_upgrade test to the TAP
framework. This commit just puts a basic TAP test in place so that we
can see how the build farm behaves, since the build farm client has some
special knowledge of the pg_upgrade tests.
Author: Michael Paquier <michael.paquier@gmail.com>
Remove code meant for upgrading to a particular version of PostgreSQL
9.0. Since pg_upgrade only supports upgrading to the current major
version, this code is no longer useful.
In the frontend Makefiles that pull in libpgfeutils, we'd generally
done it like this:
LDFLAGS += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)
That method is badly broken, as seen in bug #14742 from Chris Ruprecht.
The -L flag for src/fe_utils ends up being placed after whatever random
-L flags are in LDFLAGS already. That puts us at risk of pulling in
libpgfeutils.a from some previous installation rather than the freshly
built one in src/fe_utils. Also, the lack of an "override" is hazardous
if someone tries to specify some LDFLAGS on the make command line.
The correct way to do it is like this:
override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
so that libpgfeutils, along with libpq, libpgport, and libpgcommon, are
guaranteed to be pulled in from the build tree and not from any referenced
system directory, because their -L flags will appear first.
In some places we'd been even lazier and done it like this:
LDFLAGS += -L$(top_builddir)/src/fe_utils -lpgfeutils -lpq
which is subtly wrong in an additional way: on platforms where we can't
restrict the symbols exported by libpq.so, it allows libpgfeutils to
latch onto libpgport and libpgcommon symbols from libpq.so, rather than
directly from those static libraries as intended. This carries hazards
like those explained in the comments for the libpq_pgport macro.
In addition to fixing the broken libpgfeutils usages, I tried to
standardize on using $(libpq_pgport) like so:
override LDFLAGS := $(libpq_pgport) $(LDFLAGS)
even where libpgfeutils is not in the picture. This makes no difference
right now but will hopefully discourage future mistakes of the same ilk.
And it's more like the way we handle CPPFLAGS in libpq-using Makefiles.
In passing, just for consistency, make pgbench include PTHREAD_LIBS the
same way everyplace else does, ie just after LIBS rather than in some
random place in the command line. This might have practical effect if
there are -L switches in that macro on some platform.
It looks to me like the MSVC build scripts are not affected by this
error, but someone more familiar with them than I might want to double
check.
Back-patch to 9.6 where libpgfeutils was introduced. In 9.6, the hazard
this error creates is that a reinstallation might link to the prior
installation's copy of libpgfeutils.a and thereby fail to absorb a
minor-version bug fix.
Discussion: https://postgr.es/m/20170714125106.9231.13772@wrigleys.postgresql.org
Traditionally, "pg_ctl start -w" has waited for the server to become
ready to accept connections by attempting a connection once per second.
That has the major problem that connection issues (for instance, a
kernel packet filter blocking traffic) can't be reliably told apart
from server startup issues, and the minor problem that if server startup
isn't quick, we accumulate "the database system is starting up" spam
in the server log. We've hacked around many of the possible connection
issues, but it resulted in ugly and complicated code in pg_ctl.c.
In commit c61559ec3, I changed the probe rate to every tenth of a second.
That prompted Jeff Janes to complain that the log-spam problem had become
much worse. In the ensuing discussion, Andres Freund pointed out that
we could dispense with connection attempts altogether if the postmaster
were changed to report its status in postmaster.pid, which "pg_ctl start"
already relies on being able to read. This patch implements that, teaching
postmaster.c to report a status string into the pidfile at the same
state-change points already identified as being of interest for systemd
status reporting (cf commit 7d17e683f). pg_ctl no longer needs to link
with libpq at all; all its functions now depend on reading server files.
In support of this, teach AddToDataDirLockFile() to allow addition of
postmaster.pid lines in not-necessarily-sequential order. This is needed
on Windows where the SHMEM_KEY line will never be written at all. We still
have the restriction that we don't want to truncate the pidfile; document
the reasons for that a bit better.
Also, fix the pg_ctl TAP tests so they'll notice if "start -w" mode
is broken --- before, they'd just wait out the sixty seconds until
the loop gives up, and then report success anyway. (Yes, I found that
out the hard way.)
While at it, arrange for pg_ctl to not need to #include miscadmin.h;
as a rather low-level backend header, requiring that to be compilable
client-side is pretty dubious. This requires moving the #define's
associated with the pidfile into a new header file, and moving
PG_BACKEND_VERSIONSTR someplace else. For lack of a clearly better
"someplace else", I put it into port.h, beside the declaration of
find_other_exec(), since most users of that macro are passing the value to
find_other_exec(). (initdb still depends on miscadmin.h, but at least
pg_ctl and pg_upgrade no longer do.)
In passing, fix main.c so that PG_BACKEND_VERSIONSTR actually defines the
output of "postgres -V", which remarkably it had never done before.
Discussion: https://postgr.es/m/CAMkU=1xJW8e+CTotojOMBd-yzUvD0e_JZu2xHo=MnuZ4__m7Pg@mail.gmail.com
Don't move parenthesized lines to the left, even if that means they
flow past the right margin.
By default, BSD indent lines up statement continuation lines that are
within parentheses so that they start just to the right of the preceding
left parenthesis. However, traditionally, if that resulted in the
continuation line extending to the right of the desired right margin,
then indent would push it left just far enough to not overrun the margin,
if it could do so without making the continuation line start to the left of
the current statement indent. That makes for a weird mix of indentations
unless one has been completely rigid about never violating the 80-column
limit.
This behavior has been pretty universally panned by Postgres developers.
Hence, disable it with indent's new -lpl switch, so that parenthesized
lines are always lined up with the preceding left paren.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
The new indent version includes numerous fixes thanks to Piotr Stefaniak.
The main changes visible in this commit are:
* Nicer formatting of function-pointer declarations.
* No longer unexpectedly removes spaces in expressions using casts,
sizeof, or offsetof.
* No longer wants to add a space in "struct structname *varname", as
well as some similar cases for const- or volatile-qualified pointers.
* Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely.
* Fixes bug where comments following declarations were sometimes placed
with no space separating them from the code.
* Fixes some odd decisions for comments following case labels.
* Fixes some cases where comments following code were indented to less
than the expected column 33.
On the less good side, it now tends to put more whitespace around typedef
names that are not listed in typedefs.list. This might encourage us to
put more effort into typedef name collection; it's not really a bug in
indent itself.
There are more changes coming after this round, having to do with comment
indentation and alignment of lines appearing within parentheses. I wanted
to limit the size of the diffs to something that could be reviewed without
one's eyes completely glazing over, so it seemed better to split up the
changes as much as practical.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
When commit 0f33a719fd removed the
instructions to start/stop the new cluster before running rsync, it was
now possible for pg_resetwal/pg_resetxlog to leave the final WAL record
at wal_level=minimum, preventing upgraded standby servers from
reconnecting.
This patch fixes that by having pg_upgrade unconditionally start/stop
the new cluster after pg_resetwal/pg_resetxlog has run.
Backpatch through 9.2 since, though the instructions were added in PG
9.5, they worked all the way back to 9.2.
Discussion: https://postgr.es/m/20170620171844.GC24975@momjian.us
Backpatch-through: 9.2
Doing a cross-version upgrade test with test.sh evidently hasn't been
tested since circa 9.2, because the script lacked case branches for
old-version servers newer than 9.1. Future-proof that a bit, and
clean up breakage induced by our recent drop of V0 function call
protocol (namely that oldstyle_length() isn't in the regression
suite anymore).
(This isn't enough to make the test work perfectly cleanly across
versions, but at least it finishes and provides dump files that
you can diff manually. One issue I didn't touch is that we might
want to execute the "reindex_hash.sql" file in the new DB before
dumping it, so that the hash indexes don't vanish from the dump.)
Improve the TESTING doc file: put the tl;dr version at the top not
the bottom, and bring its explanation of how to run a cross-version
test up to speed, since the installcheck target isn't there and won't
be resurrected. Improve the comment in the Makefile about why not.
In passing, teach .gitignore and "make clean" about a couple more
junk output files.
Discussion: https://postgr.es/m/14058.1496892482@sss.pgh.pa.us
Mark any old hash indexes as invalid so that they don't get used, and
create a script to run REINDEX on all of them. Without this, we'd
still try to use any upgraded hash indexes, but it would fail.
Amit Kapila, reviewed by me. Per a suggestion from Tom Lane.
Discussion: http://postgr.es/m/CAA4eK1Jidtagm7Q81q-WoegOVgkotv0OxvHOjFxcvFRP4X=mSw@mail.gmail.com
Commit 96a7128b made pg_dump and pg_dumpall sync their output by
default. However, there's no great need for that in testing, and it
could impose a performance penalty, so we add the --no-sync flag to most
of the test cases.
Michael Paquier
Although it's reasonable to expect that most of these constants will
never change, that does not make it good programming style to hard-code
the value rather than using the RELKIND_FOO macros.
Discussion: https://postgr.es/m/11145.1488931324@sss.pgh.pa.us
c.h #includes a number of core libc header files, such as <stdio.h>.
There's no point in re-including these after having read postgres.h,
postgres_fe.h, or c.h; so remove code that did so.
While at it, also fix some places that were ignoring our standard pattern
of "include postgres[_fe].h, then system header files, then other Postgres
header files". While there's not any great magic in doing it that way
rather than system headers last, it's silly to have just a few files
deviating from the general pattern. (But I didn't attempt to enforce this
globally, only in files I was touching anyway.)
I'd be the first to say that this is mostly compulsive neatnik-ism,
but over time it might save enough compile cycles to be useful.
Commit 85c11324ca renamed pg_resetxlog
to pg_resetwal, but didn't make pg_upgrade smart enough to cope with
the situation.
Michael Paquier, per a complaint from Jeff Janes
Previously, we left such literals alone if the query or subquery had
no properties forcing a type decision to be made (such as an ORDER BY or
DISTINCT clause using that output column). This meant that "unknown" could
be an exposed output column type, which has never been a great idea because
it could result in strange failures later on. For example, an outer query
that tried to do any operations on an unknown-type subquery output would
generally fail with some weird error like "failed to find conversion
function from unknown to text" or "could not determine which collation to
use for string comparison". Also, if the case occurred in a CREATE VIEW's
query then the view would have an unknown-type column, causing similar
failures in queries trying to use the view.
To fix, at the tail end of parse analysis of a query, forcibly convert any
remaining "unknown" literals in its SELECT or RETURNING list to type text.
However, provide a switch to suppress that, and use it in the cases of
SELECT inside a set operation or INSERT command. In those cases we already
had type resolution rules that make use of context information from outside
the subquery proper, and we don't want to change that behavior.
Also, change creation of an unknown-type column in a relation from a
warning to a hard error. The error should be unreachable now in CREATE
VIEW or CREATE MATVIEW, but it's still possible to explicitly say "unknown"
in CREATE TABLE or CREATE (composite) TYPE. We want to forbid that because
it's nothing but a foot-gun.
This change creates a pg_upgrade failure case: a matview that contains an
unknown-type column can't be pg_upgraded, because reparsing the matview's
defining query will now decide that the column is of type text, which
doesn't match the cstring-like storage that the old materialized column
would actually have. Add a checking pass to detect that. While at it,
we can detect tables or composite types that would fail, essentially
for free. Those would fail safely anyway later on, but we might as
well fail earlier.
This patch is by me, but it owes something to previous investigations
by Rahila Syed. Also thanks to Ashutosh Bapat and Michael Paquier for
review.
Discussion: https://postgr.es/m/CAH2L28uwwbL9HUM-WR=hromW1Cvamkn7O-g8fPY2m=_7muJ0oA@mail.gmail.com
Turns out this has been broken for years and we'd not noticed. The one
case that was getting exercised in the buildfarm, or probably anywhere
else, was postgres_fdw.sl's reference to libpq.sl; and it turns out that
that was always going to libpq.sl in the actual installation directory
not the temporary install. We'd not noticed because the buildfarm script
does "make install" before it tests contrib. However, the recent addition
of a logical-replication test to the core regression scripts resulted in
trying to use libpqwalreceiver.sl before "make install" happens, and that
failed for lack of finding libpq.sl, as shown by failures on buildfarm
members gaur and pademelon.
There are two changes needed to fix it: the magic environment variable to
specify shlib search path at runtime is SHLIB_PATH not LD_LIBRARY_PATH,
and the shlib link command needs to specify the +s switch else the library
will not honor SHLIB_PATH.
I'm not quite sure why buildfarm members anole and gharial (HPUX 11) didn't
show the same failure. Consulting man pages on the web says that HPUX 11
honors both LD_LIBRARY_PATH and SHLIB_PATH, which would explain half of it,
and the rather confusing wording I've been able to find suggests that +s
might effectively be the default in HPUX 11. But it seems at least as
likely that there's just a libpq.so installed in /usr/lib on that machine;
as long as it's not too ancient, that would satisfy the test. In any case
I do not think this patch will break HPUX 11.
At the moment I don't see a need to back-patch this, since it only matters
for testing purposes, not to mention that HPUX 10 is probably dead in the
real world anyway.
In 9.5, the default pg_ctl stop mode was changed from "smart" to "fast".
pg_upgrade still thought the default mode was "smart" and only specified
the mode when "fast" was asked for. This results in using "fast" all
the time. It's not clear what the effect in practice is, but fix it
nonetheless to restore the previous behavior.
Previously, pg_upgrade migrated sequence data like tables by copying the
on-disk file. This does not allow any changes in the on-disk format for
sequences. It's simpler to just have pg_dump set the new sequence
values as it normally does. To do that, create a hidden submode in
pg_dump that dumps sequence data even when a schema-only dump is
requested, and trigger that submode in binary upgrade mode. (This new
submode could easily be exposed as a command-line option, but it has
limited use outside of pg_dump and would probably cause some confusion,
so we don't do that at this time.)
Reviewed-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
"xlog" is not a particularly clear abbreviation for "write-ahead log",
and it sometimes confuses users into believe that the contents of the
"pg_xlog" directory are not critical data, leading to unpleasant
consequences. So, rename the directory to "pg_wal".
This patch modifies pg_upgrade and pg_basebackup to understand both
the old and new directory layouts; the former is necessary given the
purpose of the tool, while the latter merely avoids an unnecessary
backward-compatibility break.
We may wish to consider renaming other programs, switches, and
functions which still use the old "xlog" naming to also refer to
"wal". However, that's still under discussion, so let's do just this
much for now.
Discussion: CAB7nPqTeC-8+zux8_-4ZD46V7YPwooeFxgndfsq5Rg8ibLVm1A@mail.gmail.com
Michael Paquier
pg_upgrade checks whether all the shared libraries used in the old cluster
are also available in the new one by issuing LOAD for each library name.
Previously, it cared not what order it did the LOADs in. Ideally it
should not have to care, but currently the transform modules in contrib
fail unless both the language and datatype modules they depend on are
loaded first. A backend-side solution for that looks possible but
probably not back-patchable, so as a stopgap measure, let's do the LOAD
tests in order by library name length. That should fix the problem for
reasonably-named transform modules, eg "hstore_plpython" will be loaded
after both "hstore" and "plpython". (Yeah, it's a hack.)
In a larger sense, having a predictable order of these probes is a good
thing, since it will make upgrades predictably work or not work in the
face of inter-library dependencies. Also, this patch replaces O(N^2)
de-duplication logic with O(N log N) logic, which could matter in
installations with very many databases. So I don't foresee reverting this
even after we have a proper fix for the library-dependency problem.
In passing, improve a couple of SQL queries used here.
Per complaint from Andrew Dunstan that pg_upgrade'ing the transform contrib
modules failed. Back-patch to 9.5 where transform modules were introduced.
Discussion: <f7ac29f3-515c-2a44-21c5-ec925053265f@dunslane.net>
The previous design for this had copyFile(), linkFile(), and
rewriteVisibilityMap() returning strerror strings, with the caller
producing one-size-fits-all error messages based on that. This made it
impossible to produce messages that described the failures with any degree
of precision, especially not short-read problems since those don't set
errno at all.
Since pg_upgrade has no intention of continuing after any error in this
area, let's fix this by just letting these functions call pg_fatal() for
themselves, making it easy for each point of failure to have a suitable
error message. Taking this approach also allows dropping cleanup code
that was unnecessary and was often rather sloppy about preserving errno.
To not lose relevant info that was reported before, pass in the schema name
and table name of the current table so that they can be included in the
error reports.
An additional problem was the use of getErrorText(), which was flat out
wrong for all but a couple of call sites, because it unconditionally did
"_dosmaperr(GetLastError())" on Windows. That's only appropriate when
reporting an error from a Windows-native API, which only a couple of
the callers were actually doing. Thus, even the reported strerror string
would be unrelated to the actual failure in many cases on Windows.
To fix, get rid of getErrorText() altogether, and just have call sites
do strerror(errno) instead, since that's the way all the rest of our
frontend programs do it. Add back the _dosmaperr() calls in the two
places where that's actually appropriate.
In passing, make assorted messages hew more closely to project style
guidelines, notably by removing initial capitals in not-complete-sentence
primary error messages. (I didn't make any effort to clean up places
I didn't have another reason to touch, though.)
Per discussion of a report from Thomas Kellerer. Back-patch to 9.6,
but no further; given the relative infrequency of reports of problems
here, it's not clear it's worth adapting the patch to older branches.
Patch by me, but with credit to Alvaro Herrera for spotting the issue
with getErrorText's misuse of _dosmaperr().
Discussion: <nsjrbh$8li$1@blaine.gmane.org>
This is new code in 9.6, and evidently we missed out testing it as
thoroughly as it should have been. Bugs fixed here:
1. Use binary not text mode to open the files on Windows. Before, if
the visibility map chanced to contain two bytes that looked like \r\n,
Windows' read() would convert that to \n, which both corrupts the map
data and causes the file to look shorter than it should. Unless you
were *very* unlucky and had an exact multiple of 8K such occurrences
in each VM file, this would cause pg_upgrade to report a failure,
though with a rather obscure error message.
2. The code for copying rebuilt bytes into the output was simply wrong.
It chanced to work okay on little-endian machines but would emit the
bytes in the wrong order on big-endian, leading to silent corruption
of the visibility map data.
3. The code was careless about alignment of the working buffers. Given
all three of an alignment-picky architecture, a compiler that chooses
to put the new_vmbuf[] local variable at an odd starting address, and
a checksum-enabled database, pg_upgrade would dump core.
Point one was reported by Thomas Kellerer, the other two detected by
code-reading.
Point two is much the nastiest of these issues from an impact standpoint,
though fortunately it affects only a minority of users. The Windows issue
will definitely bite people, but it seems quite unlikely that there would
be undetected corruption from that.
In addition, I failed to resist the temptation to do some minor cosmetic
adjustments, mostly improving the comments.
It would be a good idea to try to improve the error reporting here, but
that seems like material for a separate patch.
Discussion: <nsjrbh$8li$1@blaine.gmane.org>
This is a good bit more complicated than the average new-version stamping
commit, because it includes various adjustments in pursuit of changing
from three-part to two-part version numbers. It's likely some further
work will be needed around that change; but this is enough to get through
the regression tests, at least in Unix builds.
Peter Eisentraut and Tom Lane
Due to simplistic quoting and confusion of database names with conninfo
strings, roles with the CREATEDB or CREATEROLE option could escalate to
superuser privileges when a superuser next ran certain maintenance
commands. The new coding rule for PQconnectdbParams() calls, documented
at conninfo_array_parse(), is to pass expand_dbname=true and wrap
literal database names in a trivial connection string. Escape
zero-length values in appendConnStrVal(). Back-patch to 9.1 (all
supported versions).
Nathan Bossart, Michael Paquier, and Noah Misch. Reviewed by Peter
Eisentraut. Reported by Nathan Bossart.
Security: CVE-2016-5424
start_postmaster() registered stop_postmaster_atexit as an atexit(3)
callback each time through, although the obvious intention was to do
so only once per program run. The extra registrations were harmless,
so long as we didn't exceed ATEXIT_MAX, but still it's a bug.
Artur Zakirov, with bikeshedding by Kyotaro Horiguchi and me
Discussion: <d279e817-02b5-caa6-215f-cfb05dce109a@postgrespro.ru>
For historical reasons, copyFile and rewriteVisibilityMap took a force
argument which was always passed as true, meaning that any existing
file should be overwritten. However, it seems much safer to instead
fail if a file we need to write already exists.
While we're at it, remove the "force" argument altogether, since it was
never passed as anything other than true (and now we would never pass
it as anything other than false, if we kept it).
Noted by Andres Freund during post-commit review of the patch that added
rewriteVisibilityMap, commit 7087166a88,
but this also changes the behavior when copying files without rewriting
them.
Patch by Masahiko Sawada.
In the old logic, if read() were to return an error, we'd silently stop
rewriting the visibility map at that point in the file. That's safe,
but reporting the error is better, so do that instead.
Report by Andres Freund. Patch by Masahiko Sawada, with one correction
by me.
This patch essentially reverts commit 4c6780fd17, in favor of a much
simpler solution for the case where the new cluster would choose to create
a TOAST table but the old cluster doesn't have one: just don't create a
TOAST table.
The existing code failed in at least two different ways if the situation
arose: (1) ALTER TABLE RESET didn't grab an exclusive lock, so that the
lock sanity check in create_toast_table failed; (2) pg_upgrade did not
provide a pg_type OID for the new toast table, so that the crosscheck in
TypeCreate failed. While both these problems were introduced by later
patches, they show that the hack being used to cause TOAST table creation
is overwhelmingly fragile (and untested). I also note that before the
TypeCreate crosscheck was added, the code would have resulted in assigning
an indeterminate pg_type OID to the toast table, possibly causing a later
OID conflict in that catalog; so that it didn't really work even when
committed.
If we simply don't create a TOAST table, there will only be a problem if
the code tries to store a tuple that's wider than a page, and field
compression isn't sufficient to get it under a page. Given that the TOAST
creation threshold is intended to be about a quarter of a page, it's very
hard to believe that cross-version differences in the do-we-need-a-toast-
table heuristic could result in an observable problem. So let's just
follow the old version's conclusion about whether a TOAST table is needed.
(If we ever do change needs_toast_table() so much that this conclusion
doesn't apply, we can devise a solution at that time, and hopefully do
it in a less klugy way than 4c6780fd17 did.)
Back-patch to 9.3, like the previous patch.
Discussion: <8110.1462291671@sss.pgh.pa.us>
