Here's only a part of the reply I should do, but as to I/O error
checking ...
Here's a list of system calls and other external function/library calls
used in pg_lesslog patch series, together with how current patch checks
each errors and how current postgresql source handles the similar calls:
--------------------------------
1. No error check is done
1-1. fileno()
fileno() is called against stdin and stdout from pg_compresslog.c
and pg_decompresslog.c. They are intended to be invoked from a shell
and so stdin and stdout are both available. fileno() error occurs only
if invoker of pg_compresslog or pg_decompresslog closes stdin and/or
stdout before the invoker executes them. I found similar fileno()
usage in pg_dump/pg_backup_archive.c and postmaster/syslogger.c. I
don't think this is an issue.
1-2. fflush()
fflush() is called against stdout within a debug routine, debug.c.
Such usage can also be found in bin/initdb.c, bin/scripts/createdb.c,
bin/psql/common.c and more. I don't think this is an issue either.
1-3. printf() and fprintf()
It is common practice not to check the error. We can find such
calls in many of existing source codes.
1-4. strerror()
It is checked that system call returns error before calling
strerror. Similar code can be found in other PostgreSQL source too.
----------------------------------
2. Error check is done
All the following function calls are associated with return value check.
open(), close(), fstat(), read(), write()
-----------------------------------
3. Functions do not return error
The following functin will not return errors, so no error check is needed.
exit(), memcopy(), memset(), strcmp()
------------------------------------
I hope this helps.
Regards;
Tom Lane wrote:
> "Simon Riggs" <[EMAIL PROTECTED]> writes:
>> Writing lots of additional code simply to remove a parameter that
>> *might* be mis-interpreted doesn't sound useful to me, especially when
>> bugs may leak in that way. My take is that this is simple and useful
>> *and* we have it now; other ways don't yet exist, nor will they in time
>> for 8.3.
>
> The potential for misusing the switch is only one small part of the
> argument; the larger part is that this has been done in the wrong way
> and will cost performance unnecessarily. The fact that it's ready
> now is not something that I think should drive our choices.
>
> I believe that it would be possible to make the needed core-server
> changes in time for 8.3, and then to work on compress/decompress
> on its own time scale and publish it on pgfoundry; with the hope
> that it would be merged to contrib or core in 8.4. Frankly the
> compress/decompress code needs work anyway before it could be
> merged (eg, I noted a distinct lack of I/O error checking).
>
> regards, tom lane
>
--
-------------
Koichi Suzuki
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