Re: Specifying the log file name of pgbench -l option

Hello Masahiko,

So I would suggest to:
 - fix the compilation issue
 - leave -l/--log as it is, i.e. use "pgbench_log" as a prefix
 - add --log-prefix=... (long option only) for changing this prefix

I agree. It's better to add the separated option to specify the prefix
of log file instead of changing the existing behaviour. Attached
latest patch incorporated review comments.
Please review it.

Patch applies, compiles and works for me.

This new option is for benchmarking, so "benchmarking_option_set" should be set to true.

To simplify the code, I would suggest to initialize explicitely "logfile_prefix" to the default value which is then overriden when the option is set, which allows to get rid of the "prefix" variable later.

There is no reason to change the documentation by breaking a line at another place if the text is not changed (where ... with 1).

I would suggest to simplify a little bit the documentation:
  "prefix of log file ..." ->
  "default log file prefix that can be changed with <option>...</>"

Otherwise the explanations seem clear enough to me. If a native English speaker could check them though, it would be nice.