Thread

  1. pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-01-15T08:51:10Z

    Right now we have a single table on
    http://www.postgresql.org/docs/devel/static/monitoring-stats.html#MONITORING-STATS-VIEWS
    that lists all our statistics views. It makes for difficult to parse
    descriptions like "One row only, showing cluster-wide statistics from
    the background writer: number of scheduled checkpoints, requested
    checkpoints, buffers written by checkpoints and cleaning scans, and
    the number of times the background writer stopped a cleaning scan
    because it had written too many buffers. Also includes statistics
    about the shared buffer pool, including buffers written by backends
    (that is, not by the background writer), how many times those backends
    had to execute their own fsync calls (normally the background writer
    handles those even when the backend does its own write), total buffers
    allocated, and time of last statistics reset."
    
    I'd like to turn that into one table for each view, with two columns,
    one being the name the other one being the description. That'll also
    make it possible to expand on the descriptions without making it
    completley unreadable, should we want to.
    
    Comments?Objections?
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  2. Re: pgstat documentation tables

    Greg Smith <greg@2ndquadrant.com> — 2012-01-15T09:35:18Z

    On 01/15/2012 03:51 AM, Magnus Hagander wrote:
    > I'd like to turn that into one table for each view, with two columns,
    > one being the name the other one being the description. That'll also
    > make it possible to expand on the descriptions without making it
    > completley unreadable, should we want to.
    
    Scott Mead's pg_stat_activity refactoring patch already was forced 
    toward doing something similar for its documentation to be readable 
    (maybe exactly the same as you were thinking, can't tell because my 
    SGML-fu is weak) .  I feel doing this for every view in there is 
    inevitable, just a matter of when to bite on the problem.  This whole 
    section is barely usable in its current form.  I strongly hope the 
    pg_stat_activity patch goes in, which will be close to a compelling 
    event to motivate fixing the rest of them in a similar way.  I would 
    advocate leading with that one until it seems right, then adopting the 
    same style of reorg to the rest until they're all converted.
    
    -- 
    Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
    PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com
    
    
    
  3. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-01-15T14:34:12Z

    On Sun, Jan 15, 2012 at 10:35, Greg Smith <greg@2ndquadrant.com> wrote:
    > On 01/15/2012 03:51 AM, Magnus Hagander wrote:
    >>
    >> I'd like to turn that into one table for each view, with two columns,
    >> one being the name the other one being the description. That'll also
    >> make it possible to expand on the descriptions without making it
    >> completley unreadable, should we want to.
    >
    >
    > Scott Mead's pg_stat_activity refactoring patch already was forced toward
    > doing something similar for its documentation to be readable (maybe exactly
    > the same as you were thinking, can't tell because my SGML-fu is weak) .  I
    > feel doing this for every view in there is inevitable, just a matter of when
    > to bite on the problem.  This whole section is barely usable in its current
    > form.  I strongly hope the pg_stat_activity patch goes in, which will be
    > close to a compelling event to motivate fixing the rest of them in a similar
    > way.  I would advocate leading with that one until it seems right, then
    > adopting the same style of reorg to the rest until they're all converted.
    
    Yes, the pg_stat_activity patch will make it more important - but I
    want to do it for *all* of them...
    
    I'll be happy to do the mechanical work on turning them into table,
    but yes, I was planning to look at the pg_stat_activity patch first
    all along :)
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  4. Re: pgstat documentation tables

    Tom Lane <tgl@sss.pgh.pa.us> — 2012-01-15T17:20:44Z

    Magnus Hagander <magnus@hagander.net> writes:
    > Right now we have a single table on
    > http://www.postgresql.org/docs/devel/static/monitoring-stats.html#MONITORING-STATS-VIEWS
    > that lists all our statistics views ...
    > I'd like to turn that into one table for each view,
    
    Please follow the style already used for system catalogs; ie I think
    there should be a summary table with one entry per view, and then a
    separate description and table-of-columns for each view.
    
    			regards, tom lane
    
    
  5. Re: pgstat documentation tables

    Greg Smith <greg@2ndquadrant.com> — 2012-01-16T01:03:16Z

    On 01/15/2012 12:20 PM, Tom Lane wrote:
    > Please follow the style already used for system catalogs; ie I think
    > there should be a summary table with one entry per view, and then a
    > separate description and table-of-columns for each view.
    
    Yes, that's a perfect precedent.  I think the easiest path forward here 
    is to tweak the updated pg_stat_activity documentation, since that's 
    being refactoring first anyway.  That can be reformatted until it looks 
    just like the system catalog documentation.  And then once that's done, 
    the rest of them can be converted over to follow the same style.  I'd be 
    willing to work on doing that in a way that improves what is documented, 
    too.  The difficulty of working with the existing tables has been the 
    deterrent for improving that section to me.
    
    -- 
    Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
    PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com
    
    
    
  6. Re: pgstat documentation tables

    Alvaro Herrera <alvherre@commandprompt.com> — 2012-01-16T16:01:50Z

    
    Bruce had a patch to turn SGML descriptions of system view into comments
    via some Perl program or something.  He posted it many moons ago and I
    haven't seen an updated version.  Bruce, do you have something to say on
    this topic?
    
    -- 
    Álvaro Herrera <alvherre@commandprompt.com>
    The PostgreSQL Company - Command Prompt, Inc.
    PostgreSQL Replication, Consulting, Custom Development, 24x7 support
    
    
  7. Re: pgstat documentation tables

    Peter Eisentraut <peter_e@gmx.net> — 2012-01-16T18:41:09Z

    On sön, 2012-01-15 at 12:20 -0500, Tom Lane wrote:
    > Magnus Hagander <magnus@hagander.net> writes:
    > > Right now we have a single table on
    > > http://www.postgresql.org/docs/devel/static/monitoring-stats.html#MONITORING-STATS-VIEWS
    > > that lists all our statistics views ...
    > > I'd like to turn that into one table for each view,
    > 
    > Please follow the style already used for system catalogs; ie I think
    > there should be a summary table with one entry per view, and then a
    > separate description and table-of-columns for each view.
    
    If the tables had proper table and column comments, you might even be
    able to generate the SGML documentation automatically.
    
    
    
    
  8. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-01-16T18:47:17Z

    On Mon, Jan 16, 2012 at 19:41, Peter Eisentraut <peter_e@gmx.net> wrote:
    > On sön, 2012-01-15 at 12:20 -0500, Tom Lane wrote:
    >> Magnus Hagander <magnus@hagander.net> writes:
    >> > Right now we have a single table on
    >> > http://www.postgresql.org/docs/devel/static/monitoring-stats.html#MONITORING-STATS-VIEWS
    >> > that lists all our statistics views ...
    >> > I'd like to turn that into one table for each view,
    >>
    >> Please follow the style already used for system catalogs; ie I think
    >> there should be a summary table with one entry per view, and then a
    >> separate description and table-of-columns for each view.
    >
    > If the tables had proper table and column comments, you might even be
    > able to generate the SGML documentation automatically.
    
    Well, I'd expect some of those columns to get (at least over time)
    significantly more detailed information than they have now. Certainly
    more than you'd put in comments in the catalogs. And having some sort
    of combination there seems to overcomplicate things...
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  9. Re: pgstat documentation tables

    Bruce Momjian <bruce@momjian.us> — 2012-02-08T04:01:52Z

    On Mon, Jan 16, 2012 at 01:01:50PM -0300, Alvaro Herrera wrote:
    > 
    > 
    > Bruce had a patch to turn SGML descriptions of system view into comments
    > via some Perl program or something.  He posted it many moons ago and I
    > haven't seen an updated version.  Bruce, do you have something to say on
    > this topic?
    
    Yes, I was waiting to get feedback on that but it seems the 9.2 release
    slipped right by me on that.  I guess I will try to pick it up for 9.3.
    
    How do people feel about pulling text out of the SGML docs and loading
    it into the database as table and column comments?
    
    -- 
      Bruce Momjian  <bruce@momjian.us>        http://momjian.us
      EnterpriseDB                             http://enterprisedb.com
    
      + It's impossible for everything to be true. +
    
    
  10. Re: pgstat documentation tables

    Tom Lane <tgl@sss.pgh.pa.us> — 2012-02-08T04:29:12Z

    Bruce Momjian <bruce@momjian.us> writes:
    > How do people feel about pulling text out of the SGML docs and loading
    > it into the database as table and column comments?
    
    I'm not thrilled by that proposal.  The length limits on comments are
    very much shorter than what is sensible to use in catalogs.sgml (at
    least if you want the comments to look passable in \d displays).  And
    I don't want people trying to serve two different use-cases when they
    write those.
    
    Perhaps it'd work to pull column comments from the C header files
    --- any same-line comment in catalog/pg_*.h is probably short enough to
    serve this purpose usefully.
    
    			regards, tom lane
    
    
  11. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-08T06:17:23Z

    On Feb 8, 2012 5:32 AM, "Tom Lane" <tgl@sss.pgh.pa.us> wrote:
    >
    > Bruce Momjian <bruce@momjian.us> writes:
    > > How do people feel about pulling text out of the SGML docs and loading
    > > it into the database as table and column comments?
    >
    > I'm not thrilled by that proposal.  The length limits on comments are
    > very much shorter than what is sensible to use in catalogs.sgml (at
    > least if you want the comments to look passable in \d displays).  And
    > I don't want people trying to serve two different use-cases when they
    > write those.
    
    Yes, I'd rather see longer than shorter descriptions in the docs, and this
    would turn that backwards...
    
    >
    > Perhaps it'd work to pull column comments from the C header files
    > --- any same-line comment in catalog/pg_*.h is probably short enough to
    > serve this purpose usefully.
    
    That could work a lot better..
    
    /Magnus
    
  12. Re: pgstat documentation tables

    Bruce Momjian <bruce@momjian.us> — 2012-02-08T16:13:57Z

    On Tue, Feb 07, 2012 at 11:29:12PM -0500, Tom Lane wrote:
    > Bruce Momjian <bruce@momjian.us> writes:
    > > How do people feel about pulling text out of the SGML docs and loading
    > > it into the database as table and column comments?
    > 
    > I'm not thrilled by that proposal.  The length limits on comments are
    > very much shorter than what is sensible to use in catalogs.sgml (at
    > least if you want the comments to look passable in \d displays).  And
    > I don't want people trying to serve two different use-cases when they
    > write those.
    
    I was thinking of just grabbing the first X characters from the SGML
    comments.
    
    > Perhaps it'd work to pull column comments from the C header files
    > --- any same-line comment in catalog/pg_*.h is probably short enough to
    > serve this purpose usefully.
    
    Yes, that would be simpler.
    
    -- 
      Bruce Momjian  <bruce@momjian.us>        http://momjian.us
      EnterpriseDB                             http://enterprisedb.com
    
      + It's impossible for everything to be true. +
    
    
  13. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-08T22:21:09Z

    On Wed, Feb 8, 2012 at 17:13, Bruce Momjian <bruce@momjian.us> wrote:
    > On Tue, Feb 07, 2012 at 11:29:12PM -0500, Tom Lane wrote:
    >> Bruce Momjian <bruce@momjian.us> writes:
    >> > How do people feel about pulling text out of the SGML docs and loading
    >> > it into the database as table and column comments?
    >>
    >> I'm not thrilled by that proposal.  The length limits on comments are
    >> very much shorter than what is sensible to use in catalogs.sgml (at
    >> least if you want the comments to look passable in \d displays).  And
    >> I don't want people trying to serve two different use-cases when they
    >> write those.
    >
    > I was thinking of just grabbing the first X characters from the SGML
    > comments.
    
    So that it wouldn't necessarily even make for a complete sentence?
    That seems like a really bad idea...
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  14. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-25T14:33:11Z

    On Mon, Jan 16, 2012 at 02:03, Greg Smith <greg@2ndquadrant.com> wrote:
    > On 01/15/2012 12:20 PM, Tom Lane wrote:
    >>
    >> Please follow the style already used for system catalogs; ie I think
    >> there should be a summary table with one entry per view, and then a
    >> separate description and table-of-columns for each view.
    >
    >
    > Yes, that's a perfect precedent.  I think the easiest path forward here is
    > to tweak the updated pg_stat_activity documentation, since that's being
    > refactoring first anyway.  That can be reformatted until it looks just like
    > the system catalog documentation.  And then once that's done, the rest of
    > them can be converted over to follow the same style.  I'd be willing to work
    > on doing that in a way that improves what is documented, too.  The
    > difficulty of working with the existing tables has been the deterrent for
    > improving that section to me.
    
    I've applied a patch that does this now. Hopefully, I didn't create
    too many spelling errors or such :-)
    
    I also applied a separate patch that folded the list of functions into
    the list of views, since that's where they are called, as a way to
    reduce duplicate documentation. I did it as a spearate patch to make
    it easier to back out if people think that was a bad idea...
    
    I didn't add any new documentation at this point - I wanted to get
    this patch in before it starts conflicting with work others are
    potentially doing. I also noticed there were some stats functions that
    were undocumented - the view fields were listed, but not the functions
    themselves. I haven't added those either...
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  15. Re: pgstat documentation tables

    Robert Haas <robertmhaas@gmail.com> — 2012-02-27T03:44:32Z

    On Sat, Feb 25, 2012 at 9:33 AM, Magnus Hagander <magnus@hagander.net> wrote:
    > On Mon, Jan 16, 2012 at 02:03, Greg Smith <greg@2ndquadrant.com> wrote:
    >> On 01/15/2012 12:20 PM, Tom Lane wrote:
    >>>
    >>> Please follow the style already used for system catalogs; ie I think
    >>> there should be a summary table with one entry per view, and then a
    >>> separate description and table-of-columns for each view.
    >>
    >>
    >> Yes, that's a perfect precedent.  I think the easiest path forward here is
    >> to tweak the updated pg_stat_activity documentation, since that's being
    >> refactoring first anyway.  That can be reformatted until it looks just like
    >> the system catalog documentation.  And then once that's done, the rest of
    >> them can be converted over to follow the same style.  I'd be willing to work
    >> on doing that in a way that improves what is documented, too.  The
    >> difficulty of working with the existing tables has been the deterrent for
    >> improving that section to me.
    >
    > I've applied a patch that does this now. Hopefully, I didn't create
    > too many spelling errors or such :-)
    >
    > I also applied a separate patch that folded the list of functions into
    > the list of views, since that's where they are called, as a way to
    > reduce duplicate documentation. I did it as a spearate patch to make
    > it easier to back out if people think that was a bad idea...
    
    I think it's a little awkward this way; maybe it would be better as a
    separate table column.  Or maybe it was better the way it was; I'm not
    sure.  Or maybe we could have a separate table that just gives the
    equivalences between stats table-column pairs and functions.  Of those
    ideas, I think I like "separate table in the same column" the best.
    
    Also, I wonder if we should promote section 27.2.2.1. Other Statistics
    Functions to 27.2.3.
    
    -- 
    Robert Haas
    EnterpriseDB: http://www.enterprisedb.com
    The Enterprise PostgreSQL Company
    
    
  16. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-27T10:22:16Z

    On Mon, Feb 27, 2012 at 04:44, Robert Haas <robertmhaas@gmail.com> wrote:
    > On Sat, Feb 25, 2012 at 9:33 AM, Magnus Hagander <magnus@hagander.net> wrote:
    >> On Mon, Jan 16, 2012 at 02:03, Greg Smith <greg@2ndquadrant.com> wrote:
    >>> On 01/15/2012 12:20 PM, Tom Lane wrote:
    >>>>
    >>>> Please follow the style already used for system catalogs; ie I think
    >>>> there should be a summary table with one entry per view, and then a
    >>>> separate description and table-of-columns for each view.
    >>>
    >>>
    >>> Yes, that's a perfect precedent.  I think the easiest path forward here is
    >>> to tweak the updated pg_stat_activity documentation, since that's being
    >>> refactoring first anyway.  That can be reformatted until it looks just like
    >>> the system catalog documentation.  And then once that's done, the rest of
    >>> them can be converted over to follow the same style.  I'd be willing to work
    >>> on doing that in a way that improves what is documented, too.  The
    >>> difficulty of working with the existing tables has been the deterrent for
    >>> improving that section to me.
    >>
    >> I've applied a patch that does this now. Hopefully, I didn't create
    >> too many spelling errors or such :-)
    >>
    >> I also applied a separate patch that folded the list of functions into
    >> the list of views, since that's where they are called, as a way to
    >> reduce duplicate documentation. I did it as a spearate patch to make
    >> it easier to back out if people think that was a bad idea...
    >
    > I think it's a little awkward this way; maybe it would be better as a
    > separate table column.  Or maybe it was better the way it was; I'm not
    
    The problem with a separate column is that it makes the table very
    wide (some of those functions have very long name). And it won't be
    possible to get an auto-linebreak in the function names, because
    they're too long.
    
    > sure.  Or maybe we could have a separate table that just gives the
    > equivalences between stats table-column pairs and functions.  Of those
    > ideas, I think I like "separate table in the same column" the best.
    
    That one would at least work. You mean basically:
    
    |pg_stat_database.xact_commit|pg_stat_get_db_xact_commit|
    |pg_stat_database.xact_rollback|pg_stat_get_db_xact_rollback|
    
    etc etc for each column/function, right?
    
    
    > Also, I wonder if we should promote section 27.2.2.1. Other Statistics
    > Functions to 27.2.3.
    
    I was considering that, but given that 27.2.2 is "viewing statistics",
    it does seem like a sub-section to that.. Though maybe if we make the
    lis tof views into their own section *as well*, so we have one sectoin
    for "how to view it", one for "views" and one for "other functions" it
    would make more sense.
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  17. Re: pgstat documentation tables

    Robert Haas <robertmhaas@gmail.com> — 2012-02-27T13:36:09Z

    On Mon, Feb 27, 2012 at 5:22 AM, Magnus Hagander <magnus@hagander.net> wrote:
    > The problem with a separate column is that it makes the table very
    > wide (some of those functions have very long name).
    
    Yeah, that's one thing I don't like about what you actually did,
    either - it made some of the tables much wider.
    
    >> sure.  Or maybe we could have a separate table that just gives the
    >> equivalences between stats table-column pairs and functions.  Of those
    >> ideas, I think I like "separate table in the same column" the best.
    >
    > That one would at least work. You mean basically:
    >
    > |pg_stat_database.xact_commit|pg_stat_get_db_xact_commit|
    > |pg_stat_database.xact_rollback|pg_stat_get_db_xact_rollback|
    >
    > etc etc for each column/function, right?
    
    Yeah.
    
    >> Also, I wonder if we should promote section 27.2.2.1. Other Statistics
    >> Functions to 27.2.3.
    >
    > I was considering that, but given that 27.2.2 is "viewing statistics",
    > it does seem like a sub-section to that.. Though maybe if we make the
    > lis tof views into their own section *as well*, so we have one sectoin
    > for "how to view it", one for "views" and one for "other functions" it
    > would make more sense.
    
    My thought was that a good half of those "other statistics functions"
    don't have all that much to do with viewing anything, so the logical
    argument for that section to need to be under "viewing statistics"
    seems a bit weak.
    
    -- 
    Robert Haas
    EnterpriseDB: http://www.enterprisedb.com
    The Enterprise PostgreSQL Company
    
    
  18. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-27T16:32:13Z

    On Mon, Feb 27, 2012 at 14:36, Robert Haas <robertmhaas@gmail.com> wrote:
    > On Mon, Feb 27, 2012 at 5:22 AM, Magnus Hagander <magnus@hagander.net> wrote:
    >> The problem with a separate column is that it makes the table very
    >> wide (some of those functions have very long name).
    >
    > Yeah, that's one thing I don't like about what you actually did,
    > either - it made some of the tables much wider.
    
    Uh, can you give me an example of one? While they will all become
    wider if you actually need to, I don't see any of those tables as wide
    enough to cause any trouble that automatic linebreaks don't fix?
    
    
    >>> sure.  Or maybe we could have a separate table that just gives the
    >>> equivalences between stats table-column pairs and functions.  Of those
    >>> ideas, I think I like "separate table in the same column" the best.
    >>
    >> That one would at least work. You mean basically:
    >>
    >> |pg_stat_database.xact_commit|pg_stat_get_db_xact_commit|
    >> |pg_stat_database.xact_rollback|pg_stat_get_db_xact_rollback|
    >>
    >> etc etc for each column/function, right?
    >
    > Yeah.
    
    Ok, I'll see if I can put something like that together and see what it
    looks like. Unless somebody else objects to that way?
    
    
    >>> Also, I wonder if we should promote section 27.2.2.1. Other Statistics
    >>> Functions to 27.2.3.
    >>
    >> I was considering that, but given that 27.2.2 is "viewing statistics",
    >> it does seem like a sub-section to that.. Though maybe if we make the
    >> lis tof views into their own section *as well*, so we have one sectoin
    >> for "how to view it", one for "views" and one for "other functions" it
    >> would make more sense.
    >
    > My thought was that a good half of those "other statistics functions"
    > don't have all that much to do with viewing anything, so the logical
    > argument for that section to need to be under "viewing statistics"
    > seems a bit weak.
    
    True.
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  19. Re: pgstat documentation tables

    Robert Haas <robertmhaas@gmail.com> — 2012-02-27T16:38:17Z

    On Mon, Feb 27, 2012 at 11:32 AM, Magnus Hagander <magnus@hagander.net> wrote:
    > On Mon, Feb 27, 2012 at 14:36, Robert Haas <robertmhaas@gmail.com> wrote:
    >> On Mon, Feb 27, 2012 at 5:22 AM, Magnus Hagander <magnus@hagander.net> wrote:
    >>> The problem with a separate column is that it makes the table very
    >>> wide (some of those functions have very long name).
    >>
    >> Yeah, that's one thing I don't like about what you actually did,
    >> either - it made some of the tables much wider.
    >
    > Uh, can you give me an example of one? While they will all become
    > wider if you actually need to, I don't see any of those tables as wide
    > enough to cause any trouble that automatic linebreaks don't fix?
    
    It's not so much that they become wide enough to line-wrap; it's just
    that it's harder to read.  For example, table 27-5,
    pg_stat_database_conflicts view, is now about twice the width that it
    was before, and the additional sentence is mostly junk, because 95% of
    people reading this won't care a whit.  Plus, for those who do care,
    the phrasing of the sentence (this value can also be returned
    directly...) isn't really altogether clear, at least IMHO.
    
    -- 
    Robert Haas
    EnterpriseDB: http://www.enterprisedb.com
    The Enterprise PostgreSQL Company
    
    
  20. Re: pgstat documentation tables

    Tom Lane <tgl@sss.pgh.pa.us> — 2012-02-27T17:00:44Z

    Robert Haas <robertmhaas@gmail.com> writes:
    > On Mon, Feb 27, 2012 at 11:32 AM, Magnus Hagander <magnus@hagander.net> wrote:
    >> On Mon, Feb 27, 2012 at 14:36, Robert Haas <robertmhaas@gmail.com> wrote:
    >>> Yeah, that's one thing I don't like about what you actually did,
    >>> either - it made some of the tables much wider.
    
    >> Uh, can you give me an example of one? While they will all become
    >> wider if you actually need to, I don't see any of those tables as wide
    >> enough to cause any trouble that automatic linebreaks don't fix?
    
    > It's not so much that they become wide enough to line-wrap; it's just
    > that it's harder to read.
    
    Something else to keep in mind is that PDF-format docs are not terribly
    forgiving of wide tables --- have you looked at what these look like in
    PDF?
    
    			regards, tom lane
    
    
  21. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-27T17:07:49Z

    On Mon, Feb 27, 2012 at 18:00, Tom Lane <tgl@sss.pgh.pa.us> wrote:
    > Robert Haas <robertmhaas@gmail.com> writes:
    >> On Mon, Feb 27, 2012 at 11:32 AM, Magnus Hagander <magnus@hagander.net> wrote:
    >>> On Mon, Feb 27, 2012 at 14:36, Robert Haas <robertmhaas@gmail.com> wrote:
    >>>> Yeah, that's one thing I don't like about what you actually did,
    >>>> either - it made some of the tables much wider.
    >
    >>> Uh, can you give me an example of one? While they will all become
    >>> wider if you actually need to, I don't see any of those tables as wide
    >>> enough to cause any trouble that automatic linebreaks don't fix?
    >
    >> It's not so much that they become wide enough to line-wrap; it's just
    >> that it's harder to read.
    >
    > Something else to keep in mind is that PDF-format docs are not terribly
    > forgiving of wide tables --- have you looked at what these look like in
    > PDF?
    
    I have not, and I can't seem to build them:
    openjade  -D . -D . -c
    /usr/share/sgml/docbook/stylesheet/dsssl/modular/catalog -d
    ./stylesheet.dsl -t tex -V tex-backend -i output-print -i
    include-index -V texpdf-output -V '%paper-type%'=A4 -o
    postgres-A4.tex-pdf postgres.sgml
    openjade:./stylesheet.dsl:678:2:E: flow object not accepted by port;
    only display flow objects accepted
    make: *** [postgres-A4.tex-pdf] Segmentation fault
    make: *** Deleting file `postgres-A4.tex-pdf'
    
    
    does that work for others, or did we break something globally in it?
    
    I'm not sure I've ever tried to built it on Ubuntu 12.10 before, so it
    could be that..
    
    (and same error on -US)
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  22. Re: pgstat documentation tables

    Tom Lane <tgl@sss.pgh.pa.us> — 2012-02-27T17:22:17Z

    Magnus Hagander <magnus@hagander.net> writes:
    > On Mon, Feb 27, 2012 at 18:00, Tom Lane <tgl@sss.pgh.pa.us> wrote:
    >> Something else to keep in mind is that PDF-format docs are not terribly
    >> forgiving of wide tables --- have you looked at what these look like in
    >> PDF?
    
    > I have not, and I can't seem to build them:
    > openjade  -D . -D . -c
    > /usr/share/sgml/docbook/stylesheet/dsssl/modular/catalog -d
    > ./stylesheet.dsl -t tex -V tex-backend -i output-print -i
    > include-index -V texpdf-output -V '%paper-type%'=A4 -o
    > postgres-A4.tex-pdf postgres.sgml
    > openjade:./stylesheet.dsl:678:2:E: flow object not accepted by port;
    > only display flow objects accepted
    
    Oh, not that again :-(.  We've never figured out exactly what triggers
    that AFAIR.
    
    > does that work for others, or did we break something globally in it?
    
    FWIW, I built all the back-branch versions in both US and A4 formats
    last week on Fedora 16.  Don't recall trying HEAD though.
    
    > I'm not sure I've ever tried to built it on Ubuntu 12.10 before, so it
    > could be that..
    
    FWIW, all the recent reports of this seem to be on Ubuntu or Debian.
    Don't know if that means few of us use Fedora or if it means Fedora has
    fixed this.  I wonder a bit about this patch Fedora is carrying:
    http://pkgs.fedoraproject.org/gitweb/?p=openjade.git;a=blob;f=openjade-1.3.2-gcc46.patch;h=962ac19ffea6bb6434ebb1a482d5604088192c7a;hb=fce180174c911b5982a5b1a45e09912c910e9bbf
    which is stated to be for a recent gcc change, but it does seem to
    have to do with creation of flow objects ...
    
    			regards, tom lane
    
    
  23. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-27T17:28:50Z

    On Mon, Feb 27, 2012 at 18:22, Tom Lane <tgl@sss.pgh.pa.us> wrote:
    > Magnus Hagander <magnus@hagander.net> writes:
    >> On Mon, Feb 27, 2012 at 18:00, Tom Lane <tgl@sss.pgh.pa.us> wrote:
    >>> Something else to keep in mind is that PDF-format docs are not terribly
    >>> forgiving of wide tables --- have you looked at what these look like in
    >>> PDF?
    >
    >> I have not, and I can't seem to build them:
    >> openjade  -D . -D . -c
    >> /usr/share/sgml/docbook/stylesheet/dsssl/modular/catalog -d
    >> ./stylesheet.dsl -t tex -V tex-backend -i output-print -i
    >> include-index -V texpdf-output -V '%paper-type%'=A4 -o
    >> postgres-A4.tex-pdf postgres.sgml
    >> openjade:./stylesheet.dsl:678:2:E: flow object not accepted by port;
    >> only display flow objects accepted
    >
    > Oh, not that again :-(.  We've never figured out exactly what triggers
    > that AFAIR.
    
    :-O
    
    >> does that work for others, or did we break something globally in it?
    >
    > FWIW, I built all the back-branch versions in both US and A4 formats
    > last week on Fedora 16.  Don't recall trying HEAD though.
    
    I only tried HEAD. Trying 9.1 now, and I get the same crash there. Can
    you (or someone) try it on Fedora with the latest tip of 9.1,
    including the release notes, if those broke it?
    
    
    >> I'm not sure I've ever tried to built it on Ubuntu 12.10 before, so it
    >> could be that..
    >
    > FWIW, all the recent reports of this seem to be on Ubuntu or Debian.
    > Don't know if that means few of us use Fedora or if it means Fedora has
    > fixed this.  I wonder a bit about this patch Fedora is carrying:
    > http://pkgs.fedoraproject.org/gitweb/?p=openjade.git;a=blob;f=openjade-1.3.2-gcc46.patch;h=962ac19ffea6bb6434ebb1a482d5604088192c7a;hb=fce180174c911b5982a5b1a45e09912c910e9bbf
    > which is stated to be for a recent gcc change, but it does seem to
    > have to do with creation of flow objects ...
    
    My ubuntu has gcc 4.6.1, so AFAICT it would be affected.
    
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  24. Re: pgstat documentation tables

    Magnus Hagander <magnus@hagander.net> — 2012-02-27T17:30:24Z

    On Mon, Feb 27, 2012 at 18:28, Magnus Hagander <magnus@hagander.net> wrote:
    > On Mon, Feb 27, 2012 at 18:22, Tom Lane <tgl@sss.pgh.pa.us> wrote:
    >> Magnus Hagander <magnus@hagander.net> writes:
    >>> On Mon, Feb 27, 2012 at 18:00, Tom Lane <tgl@sss.pgh.pa.us> wrote:
    >>>> Something else to keep in mind is that PDF-format docs are not terribly
    >>>> forgiving of wide tables --- have you looked at what these look like in
    >>>> PDF?
    >>
    >>> I have not, and I can't seem to build them:
    >>> openjade  -D . -D . -c
    >>> /usr/share/sgml/docbook/stylesheet/dsssl/modular/catalog -d
    >>> ./stylesheet.dsl -t tex -V tex-backend -i output-print -i
    >>> include-index -V texpdf-output -V '%paper-type%'=A4 -o
    >>> postgres-A4.tex-pdf postgres.sgml
    >>> openjade:./stylesheet.dsl:678:2:E: flow object not accepted by port;
    >>> only display flow objects accepted
    >>
    >> Oh, not that again :-(.  We've never figured out exactly what triggers
    >> that AFAIR.
    >
    > :-O
    >
    >>> does that work for others, or did we break something globally in it?
    >>
    >> FWIW, I built all the back-branch versions in both US and A4 formats
    >> last week on Fedora 16.  Don't recall trying HEAD though.
    >
    > I only tried HEAD. Trying 9.1 now, and I get the same crash there. Can
    > you (or someone) try it on Fedora with the latest tip of 9.1,
    > including the release notes, if those broke it?
    
    actually, that can't be it - Devrim built the 9.1 PDFs fine on a
    Fedora box, and there hasn't been any activity on 9.1 stable since.
    Must be the Ubuntu-is-broken thing then :(
    
    -- 
     Magnus Hagander
     Me: http://www.hagander.net/
     Work: http://www.redpill-linpro.com/
    
    
  25. Re: pgstat documentation tables

    Tom Lane <tgl@sss.pgh.pa.us> — 2012-02-27T17:34:31Z

    Magnus Hagander <magnus@hagander.net> writes:
    > On Mon, Feb 27, 2012 at 18:22, Tom Lane <tgl@sss.pgh.pa.us> wrote:
    >> FWIW, I built all the back-branch versions in both US and A4 formats
    >> last week on Fedora 16. Don't recall trying HEAD though.
    
    > I only tried HEAD. Trying 9.1 now, and I get the same crash there. Can
    > you (or someone) try it on Fedora with the latest tip of 9.1,
    > including the release notes, if those broke it?
    
    What I was building *was* the release notes, specifically to see if it
    would work or not, because we've had problems before with the PDF builds
    failing unexpectedly.  Should be exactly the same docs as 9.1 branch
    tip.  (Rechecks...) In fact, I later rebuilt postgres-US.pdf from the
    9.1.3 tarball, so that definitely was the released bits.
    
    This doesn't really prove that Fedora has a fix for the bug, of course.
    We have noted before that Fedora's style sheets sometimes result in page
    breaks at different places from other distros, and it would not be
    terribly surprising if this bug were page-break-sensitive.
    
    			regards, tom lane
    
    
  26. Re: pgstat documentation tables

    Greg Smith <greg@2ndquadrant.com> — 2012-02-27T18:47:29Z

    On 02/27/2012 12:22 PM, Tom Lane wrote:
    > FWIW, all the recent reports of this seem to be on Ubuntu or Debian.
    > Don't know if that means few of us use Fedora or if it means Fedora has
    > fixed this.
    
    I just tried building postgres-US.pdf on a RHEL-derived system, 
    Scientific Linux 6 using openjade-1.3.2-36.el6.  That gave me lots of 
    "Overfull hbox" errors, then died like this:
    
    ! pdfTeX error (ext4): \pdfendlink ended up in different nesting level 
    than \pd
    fstartlink.
    <to be read again>
                        \endgroup \set@typeset@protect
    l.895119 ...rticular type modifier value.\endPar{}
                                                       \endNode{}\Node%
    !  ==> Fatal error occurred, no output PDF file produced!
    
    
    Here are some Debian/Ubuntu platforms that all run into the other problem:
    
    Ubuntu 9.04, openjade 1.4devel1-19:  flow error
    Debian Squeeze, openjade 1.4devel1-19 : flow error
    
    I always assumed that the reason this didn't work, but the Fedoras did, 
    was because of a difference between 1.3 and 1.4.  Maybe a forward port 
    of that 1.3 patch would help.  I'm not sure what state RHEL6 is really 
    in though, I don't fully trust my SL6 system yet for this task.
    
    -- 
    Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
    PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com
    
    
  27. Re: pgstat documentation tables (pdf OK on centos)

    Erik Rijkers <er@xs4all.nl> — 2012-02-27T19:05:29Z

    On Mon, February 27, 2012 18:30, Magnus Hagander wrote:
    >>
    >>>> does that work for others, or did we break something globally in it?
    >>>
    
    FWIW: I build A4 pdf's for HEAD often (say, weekly), on centos 5; it has always worked this last
    year or so (I did tweak tex (?) parameters, long ago).
    
    I built the A4 pdf just now again without problem.
    
    Centos 5.7, openjade 1.3.2-27.
    
    Here are some observations on these pg-stat tables:
    
    Table 27-1. Standard Statistics views: looks OK in the pdf (HEAD).
    
    Table 27-2 has some of the longer GUC/function names sticking out of the table frame.  not pretty
    but it still works, they are still readable as a whole.
    
    Table 27-3 (pg_stat_bgwriter_view)  it does not look good: some GUC/function names not only stick
    outsize the table frame but are truncated (and thus become unreadable).
    
    
    I think it would be better if somehow the widths of the 3 table-columns ('Column', 'Type',
    'Description') would not be 3 columns of the same width, like they seem to be now: the 'Type'
    column  take fully one third of page-width, for short words like 'text' and 'bigint'.  The
    'Column' values too are almost always more narrow than 1/3 of the page.
    
    
    Erik Rijkers
    
    
    
    
  28. Re: pgstat documentation tables

    Tom Lane <tgl@sss.pgh.pa.us> — 2012-02-27T20:25:46Z

    Greg Smith <greg@2ndQuadrant.com> writes:
    > I just tried building postgres-US.pdf on a RHEL-derived system, 
    > Scientific Linux 6 using openjade-1.3.2-36.el6.  That gave me lots of 
    > "Overfull hbox" errors, then died like this:
    
    > ! pdfTeX error (ext4): \pdfendlink ended up in different nesting level 
    > than \pdfstartlink.
    
    This one is a known issue having to do with <link> text that crosses a
    page boundary.  It's fairly annoying but we know how to work around it:
    tweak the text to avoid having a <link> fall right there, or better
    shorten the <link> text enough so it doesn't cross a line end.
    
    If you got as far as the TeX run, though, you're not seeing the openjade
    crash.  I rather suspect that one is at bottom a similar sort of issue,
    but since it provides no feedback at all about where in the document it
    is, it's hard to do much with it.
    
    			regards, tom lane
    
    
  29. Re: pgstat documentation tables

    Tom Lane <tgl@sss.pgh.pa.us> — 2012-02-27T20:39:51Z

    Greg Smith <greg@2ndQuadrant.com> writes:
    > Here are some Debian/Ubuntu platforms that all run into the other problem:
    > Ubuntu 9.04, openjade 1.4devel1-19:  flow error
    > Debian Squeeze, openjade 1.4devel1-19 : flow error
    
    > I always assumed that the reason this didn't work, but the Fedoras did, 
    > was because of a difference between 1.3 and 1.4.
    
    Nah, I don't think so.  The oldest reports of this in our archives are
    from 7.4 era:
    http://archives.postgresql.org/pgsql-docs/2003-12/msg00024.php
    which could not have been openjade 1.4.
    
    			regards, tom lane
    
    
  30. Re: pgstat documentation tables

    Greg Smith <greg@2ndquadrant.com> — 2012-02-27T21:41:43Z

    On 02/27/2012 03:39 PM, Tom Lane wrote:
    > Greg Smith<greg@2ndQuadrant.com>  writes:
    >> Here are some Debian/Ubuntu platforms that all run into the other problem:
    >> Ubuntu 9.04, openjade 1.4devel1-19:  flow error
    >> Debian Squeeze, openjade 1.4devel1-19 : flow error
    >
    >> I always assumed that the reason this didn't work, but the Fedoras did,
    >> was because of a difference between 1.3 and 1.4.
    >
    > Nah, I don't think so.  The oldest reports of this in our archives are
    > from 7.4 era:
    > http://archives.postgresql.org/pgsql-docs/2003-12/msg00024.php
    > which could not have been openjade 1.4.
    
    I'm not so sure about that...that's 2003, and I've found RPM packages 
    including 1.4-devel going back to what looks like late 2001: 
    http://rpm.pbone.net/index.php3/stat/4/idpl/3369792/dir/turbolinux/com/OpenJade-1.4devel-2.i586.rpm.html
    
    The Postgres documentation documentation says "Downgrading to openjade 
    1.3 should get rid of this error." right now; at least I had a good 
    basis for the assumption I was making.  Other ideas suggesting that's 
    the case include the discussion you were involved in at 
    http://sourceforge.net/mailarchive/message.php?msg_id=26959520 as well 
    as the long open bug at 
    https://bugs.launchpad.net/ubuntu/+source/openjade/+bug/12431 (which has 
    a small test case showing the same error).
    
    Actually, check this out.  I've attached the test.docbook from that 
    Ubuntu bug report.  If I just run docbook2pdf on my Debian system, it 
    works fine:
    
    $ docbook2pdf test.docbook
    Using catalogs: /etc/sgml/catalog
    Using stylesheet: /usr/share/docbook-utils/docbook-utils.dsl#print
    Working on: /home/gsmith/test.docbook
    jade:/usr/share/sgml/declaration/xml.dcl:31:27:W: characters in the 
    document character set with numbers exceeding 65535 not supported
    Done.
    
    And I can view the resulting PDF.  But the test case in the bug report 
    says it's reproducible using "-p" to specify an alternate parser.  If I 
    do that, sure enough the bug pops up:
    
    $ docbook2pdf -p /usr/bin/openjade-1.4devel test.docbook
    Using catalogs: /etc/sgml/catalog
    Using stylesheet: /usr/share/docbook-utils/docbook-utils.dsl#print
    Working on: /home/gsmith/test.docbook
    /usr/bin/openjade-1.4devel:/usr/share/sgml/docbook/stylesheet/dsssl/modular/print/dbttlpg.dsl:2722:6:E: 
    flow object not accepted by port; only display flow objects accepted
    Done.
    
    That's despite the fact that my installed openjade is the same one I'm 
    referring to with the alternate parser:
    
    $ which openjade
    /usr/bin/openjade
    $ ls -l /usr/bin/openjade
    lrwxrwxrwx 1 root root 26 Jan 10 04:57 /usr/bin/openjade -> 
    /etc/alternatives/openjade
    $ ls -l /etc/alternatives/openjade
    lrwxrwxrwx 1 root root 26 Jan 10 04:57 /etc/alternatives/openjade -> 
    /usr/bin/openjade-1.4devel
    
    And the bug is still there without the symlink coming into place:
    
    $ docbook2pdf -p /usr/bin/openjade test.docbook
    Using catalogs: /etc/sgml/catalog
    Using stylesheet: /usr/share/docbook-utils/docbook-utils.dsl#print
    Working on: /home/gsmith/test.docbook
    /usr/bin/openjade:/usr/share/sgml/docbook/stylesheet/dsssl/modular/print/dbttlpg.dsl:2722:6:E: 
    flow object not accepted by port; only display flow objects accepted
    Done.
    
    Now that's just bizarre--that the problem comes and goes based on 
    whether you specific the parser by name.  The same test works fine in 
    all incarnations on my SL6 system, so this simple case seems to follow 
    the systems where the problem is and isn't in my testing so far.  Makes 
    me wonder if this is more of a memory stomping type of bug rather than a 
    functional one.  If this simple test case holds up as representative of 
    the PostgreSQL problem, that would seem an easier thing to get fixed 
    upstream.
    
    There is an open bug in this area for Debian too: 
    http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=521148
    
    That gets reproduced like this (file test2.docbook also attached):
    
    $ openjade -t tex -d /usr/share/docbook-utils/docbook-utils.dsl#print 
    /usr/share/sgml/declaration/xml.dcl test2.docbook
    openjade:test2.docbook:6:12:E: document type does not allow element 
    "glossary" here
    openjade:test2.docbook:6:12:E: end tag for "glossary" which is not finished
    openjade:test2.docbook:6:12:E: end tag for "glossary" which is not finished
    openjade:test2.docbook:7:10:E: end tag for "chapter" which is not finished
    openjade:/usr/share/sgml/docbook/stylesheet/dsssl/modular/print/dbcompon.dsl:205:3:E: 
    flow object not accepted by port; only display flow objects accepted
    
    This suggests whatever is going wrong here doesn't just impact PDF 
    creation.  And this one also works fine on the openjade 1.3 based SL6 
    server here, just need a different path for the library files:
    
    $ openjade -t tex -d 
    /usr/share/sgml/docbook/utils-0.6.14/docbook-utils.dsl#print 
    /usr/share/sgml/xml.dcl test2.docbook
    
    -- 
    Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
    PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com