On Thu, Apr 6, 2017 at 06:43:38PM -0700, David G. Johnston wrote: > On Thu, Apr 6, 2017 at 6:14 PM, Bruce Momjian <br...@momjian.us> wrote: > > On Thu, Apr 6, 2017 at 03:53:24PM -0700, David G. Johnston wrote: > > > hypothetical-set aggregates as being distinct from ordered-set > aggregates > yet > > the tables and the docs here do. > > Do you have any suggested text for that? > > > - The built-in ordered-set aggregate functions are listed in Table 9-53 and > Table 9-54. > + The built-in ordered-set aggregate functions are listed in Table 9-53 while > the built-in hypothetical-set ones are in Table 9-54. > > That's a direct translation. Reading some more, though, I think that: > > + The built-in within-group aggregate functions are listed in Table 9-53 > (ordered-set) and Table 9-54 (hypothetical-set).
I went with this, for simplicity: The built-in within-group ordered-set aggregate functions are listed in <xref linkend="functions-orderedset-table"> while the built-in within-group hypothetical-set ones are in <xref linkend="functions-hypothetical-table">. > So now we'd have: > > grouping-aggregates: > normal aggregates (no suffix modifiers, though can embed ORDER BY in the > aggregate function argument area) > > within-group aggregates (requires WITHIN GROUP suffix modifier) > ordered-set aggregates -> given parameters determine a record value, possibly > imputed (within the defined group) > hypothetical-set aggregates -> given a (virtual) record determine a parameter > (within the defined group) > > non-grouping aggregates: > window aggregates (requires OVER suffix modifier) > > The CREATE AGGREGATE only names those three specific types in the notes > section. Yes, very complicated. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription + -- Sent via pgsql-docs mailing list (pgsql-docs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-docs
