On Wed, May 12, 2021 at 6:37 PM Bharath Rupireddy <bharath.rupireddyforpostg...@gmail.com> wrote: > > On Wed, May 12, 2021 at 11:10 AM Amit Kapila <amit.kapil...@gmail.com> wrote: > > > > On Tue, May 11, 2021 at 5:38 PM Bharath Rupireddy > > <bharath.rupireddyforpostg...@gmail.com> wrote: > > > > > > I was going through the parallel vacuum docs and code. I found below > > > things, please someone clarify: > > > > > > 1) I see that a term "parallel degree" is used in the docs, code > > > comments, error messages "parallel vacuum degree must be a > > > non-negative integer", "parallel vacuum degree must be between 0 and > > > %d". Is there any specific reason to use the term "parallel degree"? > > > In the docs and code comments we generally use "parallel workers". > > > > > > > The parallel degree term is used here to indicate that we compute how > > much parallelism we can achieve based on the indexes. > > Yeah, I get it. Even if users don't specify a parallel option there > are chances that parallelism is picked. So the parallel degree is the > final number of workers that are chosen by the server for vacuuming > indexes. And, I think that parallel degree is something internal to > the server, and it's better we replace it in the vacuumdb.sgml, change > PARALLEL_DEGREE to PARALLEL_WORKERS in vacuumdb.c and change the error > message "parallel vacuum degree must be a non-negative integer" to > "parallel workers for vacuum must be greater than or equal to zero". > > Thoughts? > > > > 2) The error messages "parallel vacuum degree must be between 0 and > > > %d" and "parallel option requires a value between 0 and %d" look > > > inconsistent. > > > > > > > I think we can make them consistent. > > How about only one message "parallel option requires a value between 0 > and %d" for both cases below? IMO they essentially mean the same > thing. >
I am fine with changing what you are proposing in the above two points. Sawada-San, any thoughts? > > > > 6) I think, instead of saying "using integer background workers", we > > > can just say "using specified or lesser number of background workers". > > > From the docs: Perform index vacuum and index cleanup phases of VACUUM > > > in parallel using integer background workers > > > We can say "workers specified will be used during execution" > > > From the docs: workers specified in integer will be used during execution > > > > > The docs here refer to "PARALLEL integer" specified in specs, so not > > sure if the proposed text is better. > > IMO, "using the number of background workers specified with the > option" looks better than "using integer background workers". > Thoughts? > I am not too sure about this point. I guess we can leave it for now. -- With Regards, Amit Kapila.
