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help / color / mirror / Atom feed[PATCH v17 02/10] pg_stat_file and pg_ls_dir_* to use lstat()..
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* [PATCH v17 02/10] pg_stat_file and pg_ls_dir_* to use lstat()..
@ 2020-03-30 23:59 Justin Pryzby <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Justin Pryzby @ 2020-03-30 23:59 UTC (permalink / raw)
pg_ls_dir_* will now skip (no longer show) symbolic links, same as other
non-regular file types, as we advertize we do since 8b6d94cf6. That seems to
be the intented behavior, since irregular file types are 1) less portable; and,
2) we don't currently show a file's type except for "bool is_dir".
pg_stat_file will now 1) show metadata of links themselves, rather than their
target; and, 2) specifically, show links to directories with "is_dir=false";
and, 3) not error on broken symlinks.
---
doc/src/sgml/func.sgml | 2 +-
src/backend/utils/adt/genfile.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index e0d1eff6b5..d9b3598977 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25861,7 +25861,7 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8');
Returns a record containing the file's size, last access time stamp,
last modification time stamp, last file status change time stamp (Unix
platforms only), file creation time stamp (Windows only), and a flag
- indicating if it is a directory (or a symbolic link to a directory).
+ indicating if it is a directory.
</para>
<para>
This function is restricted to superusers by default, but other users
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index ceaa6180da..219ac160f8 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -370,7 +370,7 @@ pg_stat_file(PG_FUNCTION_ARGS)
filename = convert_and_check_filename(filename_t);
- if (stat(filename, &fst) < 0)
+ if (lstat(filename, &fst) < 0)
{
if (missing_ok && errno == ENOENT)
PG_RETURN_NULL();
@@ -596,7 +596,7 @@ pg_ls_dir_files(FunctionCallInfo fcinfo, const char *dir, bool missing_ok)
/* Get the file info */
snprintf(path, sizeof(path), "%s/%s", dir, de->d_name);
- if (stat(path, &attrib) < 0)
+ if (lstat(path, &attrib) < 0)
{
/* Ignore concurrently-deleted files, else complain */
if (errno == ENOENT)
--
2.17.0
--4LFBTxd4L5NLO6ly
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v17-0003-Add-tests-on-pg_ls_dir-before-changing-it.patch"
^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: [PATCH] Make ON CONFLICT DO NOTHING and ON CONFLICT DO UPDATE consistent
@ 2023-01-25 18:34 Andres Freund <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Andres Freund @ 2023-01-25 18:34 UTC (permalink / raw)
To: Aleksander Alekseev <[email protected]>; Tom Lane <[email protected]>; Peter Geoghegan <[email protected]>; +Cc: PostgreSQL Hackers <[email protected]>
Hi,
On 2023-01-25 18:45:12 +0300, Aleksander Alekseev wrote:
> Currently we allow self-conflicting inserts for ON CONFLICT DO NOTHING:
>
> ```
> CREATE TABLE t (a INT UNIQUE, b INT);
> INSERT INTO t VALUES (1,1), (1,2) ON CONFLICT DO NOTHING;
> -- succeeds, inserting the first row and ignoring the second
> ```
> ... but not for ON CONFLICT .. DO UPDATE:
>
> ```
> INSERT INTO t VALUES (1,1), (1,2) ON CONFLICT (a) DO UPDATE SET b = 0;
> ERROR: ON CONFLICT DO UPDATE command cannot affect row a second time
> HINT: Ensure that no rows proposed for insertion within the same
> command have duplicate constrained values.
> ```
>
> Tom pointed out in 2016 that this is actually a bug [1] and I agree.
I don't think I agree with this being a bug.
We can't sensible implement updating a row twice within a statement - hence
erroring out for ON CONFLICT DO UPDATE affecting a row twice. But what's the
justification for erroring out in the DO NOTHING case? ISTM that it's useful
to be able to handle such duplicates, and I don't immediately see what
semantic confusion or implementation difficulty we avoid by erroring out.
It seems somewhat likely that a behavioural change will cause trouble for some
of the uses of DO NOTHING out there.
Greetings,
Andres Freund
^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2023-01-25 18:34 UTC | newest]
Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed)
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2020-03-30 23:59 [PATCH v17 02/10] pg_stat_file and pg_ls_dir_* to use lstat().. Justin Pryzby <[email protected]>
2023-01-25 18:34 Re: [PATCH] Make ON CONFLICT DO NOTHING and ON CONFLICT DO UPDATE consistent Andres Freund <[email protected]>
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