Ah, seems Tom has even more detail so we will continue to discuss on that thread.
--------------------------------------------------------------------------- On Mon, Aug 3, 2020 at 07:51:51PM -0400, Bruce Momjian wrote: > On Sun, Aug 2, 2020 at 08:43:53PM -0700, David G. Johnston wrote: > > On Sun, Aug 2, 2020 at 8:17 PM osdba <mail...@163.com> wrote: > > > > hi all: > > > > In Document "Table 59-1. Built-in GiST Operator Classes": > > > > "range_ops any range type && &> &< >> << <@ -|- = @> @>"， exist double > > "@> > > "， > > > > Should be "<@ @>" ? > > > > > > > > It helps to reference the current version of the page (or provide a url > > link) > > as that section seems to have migrated to Chapter 64 - though it is > > unchanged > > even on the main development branch. > > > > The table itself is extremely difficult to read: it would be more easily > > readable if the font was monospaced, but its not. > > > > I'm reasonably confident that the equal sign is part of the second-to-last > > operator while the lone @> is the final operator. Mostly I say this because > > GiST doesn't do straight equality so a lone equal operator isn't valid. > > I dug into this. This query I think explains why the duplicate is > there: > > SELECT oprname, oprleft::regtype, oprright::regtype, oprresult::regtype > FROM pg_am > JOIN pg_opclass ON opcmethod = pg_am.oid > JOIN pg_amop ON opcfamily = pg_amop.amopfamily > JOIN pg_operator ON amopopr = pg_operator.oid > WHERE amname = 'gist' > AND opcname = 'range_ops' > ORDER BY 1 > > oprname | oprleft | oprright | oprresult > ---------+----------+------------+----------- > && | anyrange | anyrange | boolean > &< | anyrange | anyrange | boolean > &> | anyrange | anyrange | boolean > -|- | anyrange | anyrange | boolean > << | anyrange | anyrange | boolean > <@ | anyrange | anyrange | boolean > = | anyrange | anyrange | boolean > >> | anyrange | anyrange | boolean > --> @> | anyrange | anyrange | boolean > --> @> | anyrange | anyelement | boolean > > Notice that @> appears twice. (I am not sure why @> appears twice in > the SQL output, while <@ appears only once.) The PG docs explain the > duplicate: > > https://www.postgresql.org/docs/12/functions-range.html > > @> contains range int4range(2,4) @> int4range(2,3) t > @> contains element '[2011-01-01,2011-03-01)'::tsrange @> > '2011-01-10'::timestamp t > <@ range is contained by int4range(2,4) <@ int4range(1,7) > t > <@ element is contained by 42 <@ int4range(1,7) f > > There is an anyrange/anyrange version, and an anyrange/anyelement > version of @> and <@. Anyway, for the docs, I think we can either > remove the duplicate entry, or modify it to clarify one is for > anyrange/anyrange and another is for anyrange/anyelement. I suggest the > first option. > > -- > Bruce Momjian <br...@momjian.us> https://momjian.us > EnterpriseDB https://enterprisedb.com > > The usefulness of a cup is in its emptiness, Bruce Lee > > > -- Bruce Momjian <br...@momjian.us> https://momjian.us EnterpriseDB https://enterprisedb.com The usefulness of a cup is in its emptiness, Bruce Lee
