A few questionable partitioning designs have been cropping up lately
around the mailing lists. Generally, these cases have been partitioning
using too many partitions which have caused performance or OOM problems for
the users.
Since we have very little else to guide users into good design, here we
add a new section to the partitioning documentation with some best
practise guidelines for good design.
Reviewed-by: Justin Pryzby, Amit Langote, Alvaro Herrera
Discussion: https://postgr.es/m/CAKJS1f-2rx+E9mG3xrCVHupefMjAp1+tpczQa9SEOZWyU7fjEA@mail.gmail.com
Backpatch-through: 10
json_to_record(), when an output column is declared as type json or jsonb,
should emit the corresponding field of the input JSON object. But it got
this slightly wrong when the field is just a string literal: it failed to
escape the contents of the string. That typically resulted in syntax
errors if the string contained any double quotes or backslashes.
jsonb_to_record() handles such cases correctly, but I added corresponding
test cases for it too, to prevent future backsliding.
Improve the documentation, as it provided only a very hand-wavy
description of the conversion rules used by these functions.
Per bug report from Robert Vollmert. Back-patch to v10 where the
error was introduced (by commit cf35346e8).
Note that PG 9.4 - 9.6 also get this case wrong, but differently so:
they feed the de-escaped contents of the string literal to json[b]_in.
That behavior is less obviously wrong, so possibly it's being depended on
in the field, so I won't risk trying to make the older branches behave
like the newer ones.
Discussion: https://postgr.es/m/D6921B37-BD8E-4664-8D5F-DB3525765DCD@vllmrt.net
5871b884 introduced pg_trgm.word_similarity_threshold GUC, but its documentation
contains wrong indentation. This commit fixes that. Backpatch for easier
backpatching of other documentation fixes.
Discussion: https://postgr.es/m/4c735d30-ab59-fc0e-45d8-f90eb5ed3855%402ndquadrant.com
Author: Ian Barwick
Backpatch-through: 9.6
Removing shared memory and semaphores in response to server start
failure often masks the real problem, a live process associated with the
data directory; see commit 5a907404b52753c4d6c6a7c21765aeaa42fd6a3b.
Since 9.6, it's rarely necessary to kill subprocesses manually. (When
it is necessary, that commit's HINT will say as much, in all supported
versions.)
Continuous operation cannot be achieved without applying this technique,
so it needs to be properly described.
Author: Álvaro Herrera
Reported-by: Tom Lane
Discussion: https://postgr.es/m/8756.1556302759@sss.pgh.pa.us
Support of CHECK OPTION for updatable views has been added in 9.4, but
the documentation of information_schema never got the call even if the
information displayed is correct.
Author: Gilles Darold
Discussion: https://postgr.es/m/75d07704-6c74-4f26-656a-10045c01a17e@darold.net
Backpatch-through: 9.4
This makes the tool consistent with the option set of oid2name, which
has been historically using -f for filenodes, and has more recently
gained long options and --filenode via 1aaf532.
Reported-by: Peter Eisentraut
Author: Fabien Coelho
Discussion: https://postgr.es/m/97045260-fb9e-e145-a950-cf7d28c4eaea@2ndquadrant.com
This got forgotten in f56f8f which has added foreign key support for
partitioned tables. In passing, add a mention about caveats applying to
tables partitioned using inheritance regarding indexes and foreign keys.
Author: Paul A Jungwirth
Reviewed-by: Amit Langote, Michael Paquier
Discussion: https://postgr.es/m/CA+renyUuSmYgmZjKc_DfUNVZ0uttF91-FwhDVW3F7WEPj0jL5w@mail.gmail.com
Commit 41b54ba78e allowed not only VACUUM but also ANALYZE options
to take a boolean argument. But it forgot to update the documentation
for ANALYZE. This commit adds the descriptions about those ANALYZE
boolean options into the documentation.
This patch also updates tab-completion for ANALYZE boolean options.
Reported-by: Kyotaro Horiguchi
Author: Fujii Masao
Reviewed-by: Masahiko Sawada, Michael Paquier
Discussion: https://postgr.es/m/CAHGQGwHTUt-kuwgiwe8f0AvTnB+ySqJWh95jvmh-qcoKW9YA9g@mail.gmail.com
Define the meanings of the POSIX-spec character classes in line,
rather than referring to the ctype(3) man page. That man page
doesn't even exist on many modern systems, and if it does exist
it probably says the wrong things about non-ASCII characters.
Also document our non-POSIX-spec "ascii" character class.
Also, point out here that this behavior is controlled by collation or
LC_CTYPE, since the existing text explaining that is pretty far away.
Per gripe from Geert Lobbestael. Given the lack of prior complaints,
I'm not excited about back-patching this.
Discussion: https://postgr.es/m/155837022049.1359.2948065118562813468@wrigleys.postgresql.org
It appears that some variants of .** jsonpath accessor are undocumented. In
particular undocumented variants are:
.**{level}
.**{lower_level to upper_level}
.**{lower_level to last}
This commit adds missing documentation for them.
SQL's regular-expression substring() function is defined to have a
pattern argument that's separated into three subpatterns by escape-
double-quote markers; the function result is the part of the input
matching the second subpattern. The standard makes it clear that
if there is ambiguity about how to match the input to the subpatterns,
the first and third subpatterns should be taken to match the smallest
possible amount of text (i.e., they're "non greedy", in the terms of
our regex code). We were not doing it that way: the first subpattern
would eat the largest possible amount of text, causing the function
result to be shorter than what the spec requires.
Fix that by attaching explicit greediness quantifiers to the
subpatterns. (This depends on the regex fix in commit 8a29ed053;
before that, this didn't reliably change the regex engine's behavior.)
Also, by adding parentheses around each subpattern, we ensure that
"|" (OR) in the subpatterns behave sanely. Previously, "|" in the
first or third subpatterns didn't work.
This patch also makes the function throw error if you write more than
two escape-double-quote markers, and do something sane if you write
just one, and document that behavior. Previously, an odd number of
markers led to a confusing complaint about unbalanced parentheses,
while extra pairs of markers were just ignored. (Note that the spec
requires exactly two markers, but we've historically allowed there
to be none, and this patch preserves the old behavior for that case.)
In passing, adjust some substring() test cases that didn't really
prove what they said they were testing for: they used patterns
that didn't match the data string, so that the output would be
NULL whether or not the function was really strict.
Although this is certainly a bug fix, changing the behavior in back
branches seems undesirable: applications could perhaps be depending on
the old behavior, since it's not obviously wrong unless you read the
spec very closely. Hence, no back-patch.
Discussion: https://postgr.es/m/5bb27a41-350d-37bf-901e-9d26f5592dd0@charter.net
Per previous convention (see
ace397e9d24eddc56e7dffa921f506117b602d78), drop SQL:2008 and only keep
the latest two standards and SQL-92.
Note: SQL:2016-2 lists a large number of non-reserved keywords that
are really just information_schema column names related to new
features. Those kinds of thing have not previously been listed as
keywords, and this was apparently done here by mistake, since these
keywords have been removed again in post-2016 working drafts. So in
order to avoid bloating the keywords table unnecessarily, I have
omitted these erroneous keywords here.
