Обсуждение: [PATCH] Make "psql -1 < file.sql" work as with "-f"
Dear PostgreSQL developers,
Plese find attached a patch so that:
Make "psql -1 < file.sql" work as with "-f"
Make psql --single-transaction option work on a non-interactive standard input as well, so that "psql -1 <
input.sql"behaves as "psql -1 -f input.sql".
This saner/less error-prone behavior was discussed in this thread back in
June:
http://archives.postgresql.org/pgsql-hackers/2012-06/msg00785.php
I have tested it manually and it works for me. I'm not sure this is the
best possible implementation, but it is a small diff one. I haven't found
a place in the regression tests where "psql" could be tested with
different options. Did I miss something?
--
Fabien.
Here is a new submission with the expected "context diff format". > Dear PostgreSQL developers, > > Plese find attached a patch so that: > > Make "psql -1 < file.sql" work as with "-f" > > Make psql --single-transaction option work on a non-interactive > standard input as well, so that "psql -1 < input.sql" behaves as > "psql -1 -f input.sql". > > This saner/less error-prone behavior was discussed in this thread back in > June: > > http://archives.postgresql.org/pgsql-hackers/2012-06/msg00785.php > > I have tested it manually and it works for me. I'm not sure this is the best > possible implementation, but it is a small diff one. I haven't found a place > in the regression tests where "psql" could be tested with different options. > Did I miss something? -- Fabien.
On Wed, Aug 1, 2012 at 4:28 AM, Fabien COELHO <coelho@cri.ensmp.fr> wrote: > Dear PostgreSQL developers, > > Plese find attached a patch so that: > > Make "psql -1 < file.sql" work as with "-f" > > Make psql --single-transaction option work on a non-interactive > standard input as well, so that "psql -1 < input.sql" behaves as > "psql -1 -f input.sql". > > This saner/less error-prone behavior was discussed in this thread back in > June: > > http://archives.postgresql.org/pgsql-hackers/2012-06/msg00785.php > > I have tested it manually and it works for me. I'm not sure this is the best > possible implementation, but it is a small diff one. I haven't found a place > in the regression tests where "psql" could be tested with different options. > Did I miss something? I'm wondering if perhaps -- in addition to what you've done here -- we should make "psql -1" error out if reading from a terminal. Because accepting options that are intended to cause important behavior changes and then ignoring those options is Bad. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
On Wed, Aug 08, 2012 at 04:55:43PM -0400, Robert Haas wrote: > On Wed, Aug 1, 2012 at 4:28 AM, Fabien COELHO <coelho@cri.ensmp.fr> wrote: > > Dear PostgreSQL developers, > > > > Plese find attached a patch so that: > > > > Make "psql -1 < file.sql" work as with "-f" > > > > Make psql --single-transaction option work on a non-interactive > > standard input as well, so that "psql -1 < input.sql" behaves as > > "psql -1 -f input.sql". > > > > This saner/less error-prone behavior was discussed in this thread back in > > June: > > > > http://archives.postgresql.org/pgsql-hackers/2012-06/msg00785.php > > > > I have tested it manually and it works for me. I'm not sure this is the best > > possible implementation, but it is a small diff one. I haven't found a place > > in the regression tests where "psql" could be tested with different options. > > Did I miss something? > > I'm wondering if perhaps -- in addition to what you've done here -- we > should make "psql -1" error out if reading from a terminal. +1 for this. > Because accepting options that are intended to cause important > behavior changes and then ignoring those options is Bad. Yes, It Is. Cheers, David. -- David Fetter <david@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fetter@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate
On Wed, Aug 8, 2012 at 6:50 PM, David Fetter <david@fetter.org> wrote: >> I'm wondering if perhaps -- in addition to what you've done here -- we >> should make "psql -1" error out if reading from a terminal. > > +1 for this. OK, done. I had to revise the original patch pretty heavily before committing; the original patch assumed that it was OK to make psql -1 <file go through process_file() while having psql -1 <file still go through MainLoop() directly. This isn't a good idea, because that means that any other behavioral differences between process_file() and MainLoop() will be contingent on whether -1 is used, which is not what we want. And there is at least one such difference that matters: whether or not the file and line number get prepended when emitting error messages. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
> OK, done. > > I had to revise the original patch pretty heavily before committing; > the original patch assumed that it was OK to make psql -1 <file go > through process_file() while having psql -1 <file still go through > MainLoop() directly. This isn't a good idea, because that means that > any other behavioral differences between process_file() and MainLoop() > will be contingent on whether -1 is used, which is not what we want. Yep. I did that with a "smallest" and "simplest" change in mind, and beside when doing "psql -1 < file", you're hardly going to do anything else anyway, so I felt that it was not a big issue. > And there is at least one such difference that matters: whether or not > the file and line number get prepended when emitting error messages. Thanks for the improvements and for the push! -- Fabien.
On 8/9/12 9:08 AM, Robert Haas wrote: > On Wed, Aug 8, 2012 at 6:50 PM, David Fetter <david@fetter.org> wrote: >>> I'm wondering if perhaps -- in addition to what you've done here -- we >>> should make "psql -1" error out if reading from a terminal. >> >> +1 for this. > > OK, done. > > I had to revise the original patch pretty heavily before committing; My first use of 9.3beta1 in development failed because of changes introduced by this patch, specifically because of the newly introduced error psql: -1 is incompatible with -c and -l I'm not convinced this is correct. -c and -l are single-transaction actions almost by definition. This particular aspect of the change wasn't really brought up in the original thread. What was your thinking?
On Fri, May 10, 2013 at 9:50 AM, Peter Eisentraut <peter_e@gmx.net> wrote:
-- On 8/9/12 9:08 AM, Robert Haas wrote:
> On Wed, Aug 8, 2012 at 6:50 PM, David Fetter <david@fetter.org> wrote:
>>> I'm wondering if perhaps -- in addition to what you've done here -- we
>>> should make "psql -1" error out if reading from a terminal.
>>
>> +1 for this.
>
> OK, done.
>
> I had to revise the original patch pretty heavily before committing;
My first use of 9.3beta1 in development failed because of changes
introduced by this patch, specifically because of the newly introduced error
psql: -1 is incompatible with -c and -l
I'm not convinced this is correct. -c and -l are single-transaction
actions almost by definition.
This particular aspect of the change wasn't really brought up in the
original thread. What was your thinking?
FYI, I noticed this issue when building one of our applications against HEAD;
I'm not sure I agree with you vis-a-vis the -c option, as it is certainly plausible/meaningful
to do:
to do:
psql -c "begin; update [something]; insert [something]; delete [something]; commit;"
and for that to be different from
psql -c "update [something]; insert [something]; delete [something];"
Consider it stipulated that it's pretty plausible to expect things to break down if, in that
series of requests, the UPDATE fails, and it isn't nearly safe to assume that the INSERT
and/or DELETE statements would succeed after all that.
I'd be pretty happy for
psql -1 -c "update [something]; insert [something]; delete [something];"
to implicitly augment the query to:
It's a bit annoying (it bit me, giving me a complication, without any evident benefit) for psql -c "begin; update [something]; insert [something]; delete [something]; commit;"
"psql -1 -c" to refuse to run.
I'd rather that it behave similarly to "psql -1 -f", and wrap the queries in a transaction.
I'd rather that it behave similarly to "psql -1 -f", and wrap the queries in a transaction.
For it to behave badly if I try to induce transaction control (e.g. - embedding BEGIN/END
inside the queries) would not come as a surprise; that would be much the same as how
"psql -1 -f" works, where the extra BEGIN is warned as redundant and the extra COMMIT
is considered an error.
As for "psql -1 -l", it seems like a regression for that to fail. Listing the databases is
pretty much already a single transaction; adding "-1" is perhaps overspecifying things,
but it doesn't seem wrong.
pretty much already a single transaction; adding "-1" is perhaps overspecifying things,
but it doesn't seem wrong.
When confronted by a difficult problem, solve it by reducing it to the
question, "How would the Lone Ranger handle this?"
Christopher Browne <cbbrowne@gmail.com> writes:
> On Fri, May 10, 2013 at 9:50 AM, Peter Eisentraut <peter_e@gmx.net> wrote:
>> My first use of 9.3beta1 in development failed because of changes
>> introduced by this patch, specifically because of the newly introduced
>> error
>>
>> psql: -1 is incompatible with -c and -l
>>
>> I'm not convinced this is correct. -c and -l are single-transaction
>> actions almost by definition.
>>
>> This particular aspect of the change wasn't really brought up in the
>> original thread. What was your thinking?
> I'm not sure I agree with you vis-a-vis the -c option, as it is certainly
> plausible/meaningful
> to do:
> psql -c "begin; update [something]; insert [something]; delete
> [something]; commit;"
> and for that to be different from
> psql -c "update [something]; insert [something]; delete [something];"
While it might be *plausible* for those to be different, that's not
actually how -c works in practice, because it sends the string as a
single PQexec, which has the effect of making the string a single
transaction even if the string does not contain begin/end explicitly.
I think Peter is right and this error is bogus. Whatever redeeming
social value it might have for sticklers is not worth breaking existing
apps for.
regards, tom lane
> My first use of 9.3beta1 in development failed because of changes > introduced by this patch, specifically because of the newly introduced error > > psql: -1 is incompatible with -c and -l > > I'm not convinced this is correct. -c and -l are single-transaction > actions almost by definition. > > This particular aspect of the change wasn't really brought up in the > original thread. What was your thinking? AFAICR, the 3 lines patch I submitted did not include such a check. Comments by Robert in the source suggest that the -1 option is ignored under -c and -l. This is because the "transaction" is handled by process_file which is not called in these cases. However, if they are single transaction nevertheless, the guard may just be removed, even if the option does nothing? ISTM that option -l is readonly, it does not matter much. For -c, I'm not that sure. -- Fabien.
On Fri, May 10, 2013 at 9:50 AM, Peter Eisentraut <peter_e@gmx.net> wrote: > On 8/9/12 9:08 AM, Robert Haas wrote: >> On Wed, Aug 8, 2012 at 6:50 PM, David Fetter <david@fetter.org> wrote: >>>> I'm wondering if perhaps -- in addition to what you've done here -- we >>>> should make "psql -1" error out if reading from a terminal. >>> >>> +1 for this. >> >> OK, done. >> >> I had to revise the original patch pretty heavily before committing; > > My first use of 9.3beta1 in development failed because of changes > introduced by this patch, specifically because of the newly introduced error > > psql: -1 is incompatible with -c and -l > > I'm not convinced this is correct. -c and -l are single-transaction > actions almost by definition. > > This particular aspect of the change wasn't really brought up in the > original thread. What was your thinking? Well, I think my main thinking was to prevent it in interactive mode, since it doesn't work in interactive mode, and then it also seemed to make sense to prevent it in the other cases to which it does not apply. I think there are cases where you can detect the fact that -1 -c wasn't actually wrapping the command in a BEGIN and an END, but I agree it might be a bit pedantic to worry about them. There have been previous proposals to allow multiple -c and -f options, and to allow those to be intermingled; if we did that, then this would surely matter. I agree that's hypothetical though since there's no patch to do any such thing currently on the table. Generally, I think we're too lax about detecting and complaining about conflicting combinations of options. But I'm not going to stand here and hold my breath if someone else feels that this particular combination doesn't merit a complaint. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company