On Thu, Oct 25, 2018 at 01:00:08PM +1300, David Rowley wrote: > On 25 October 2018 at 11:25, David Fetter <da...@fetter.org> wrote: > > Digging a teensy bit deeper, I noticed that there's already a > > "padding" (space padding, if I understand correctly) system for parts > > of the log_line_prefix specification including %m. Did we get painted > > into a corner here back in 9.4, when the padding feature was added? > > https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=4334639f4bb9fb88c13b8dd5faca22b207248504 > > I'm not sure "painted into a corner" is the right way to think about > this.
Excellent! > Numerics immediately followed by the '%' are simply already used by > the space padding feature. If you want some other modifier then > you'll need to invent some other syntax to identify that. It looks > like using a '.' after the '%' was mentioned by Alvaro. > > I think the best way to implement this is to rename > process_log_prefix_padding into process_log_prefix_modifiers and add > an "int *precision" variable and add some code to parse and populate > that based on if there's a '.' found in the prefix. Then in > log_line_prefix() just take into account the precision for any > prefix variable that it should apply to. So, %s likely should be > altered too, although that might require some additional code to > NULLify the string if the server config is reloaded, or perhaps you > can just remember how much precision that string was made with and > only rebuild it if the required precision changes. We don't seem to > have any other floating point type prefix variables, so I don't > think any of the others need to be altered. Thanks for the detailed roadmap on this. > > Strangely, there were no tests that came with that either. David, > > did you mean to expand it past space padding, or...? > > Unsure what infrastructure existed then for testing this. > > I didn't intend to add anything else later. I don't think we have > any variables that zero padding would be that useful for, but maybe > someone might want to zero pad their pids or xids... ? They might, so I'll either put in a comment where that would go or just implement it. Best, David. -- David Fetter <david(at)fetter(dot)org> http://fetter.org/ Phone: +1 415 235 3778 Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate
