| From: | Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Kevin Grittner <kgrittn(at)gmail(dot)com>, Stephen Frost <sfrost(at)snowman(dot)net>, Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, "pgsql-hackers\(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: No longer possible to query catalogs for index capabilities? |
| Date: | 2016-08-13 00:09:50 |
| Message-ID: | 87shu9mtan.fsf@news-spur.riddles.org.uk |
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| Lists: | pgsql-hackers |
>>>>> "Tom" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
Tom> But we need to be clear in the documentation about what this
Tom> property actually means. My objection to having it answer at the
Tom> index or column level is basically that that encourages confusion
Tom> as to what it means.
OK. Here's new output with the scope changes, and some of the names
changed in an attempt to make them clearer:
cap | AM | Index | Column
--------------------+----+-------+--------
asc | | | t
desc | | | f
nulls_first | | | f
nulls_last | | | t
orderable | | | t
distance_orderable | | | f
returnable | | | t
search_array | | | t
search_nulls | | | t
clusterable | | t |
backward_scan | | t |
index_scan | | t |
bitmap_scan | | t |
can_order | t | |
can_unique | t | |
can_multi_col | t | |
can_exclude | t | |
(17 rows)
(The can_* names are reserved for the AM level where we're asking about
the abstract capabilities of the AM.)
Better? Worse? Any more improvements to the names?
--
Andrew (irc:RhodiumToad)
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