There are three static definitions of validate_relation_kind() in the
codebase, one each in table.c, indexam.c and sequence.c, validating that
the given relation is a table, an index or a sequence respectively.
The compiler knows which definition to use where because they are static.
But this could be confusing to a reader. Rename these functions so that
their names reflect the kind of relation they are validating. While at
it, also update the comments in table.c to clarify the definition of
table-like relkinds so that we don't have to maintain the exclusion list
as the set of relkinds undergoes changes.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/6d3fef19-a420-4e11-8235-8ea534bf2080%40eisentraut.org
Similarly to tables and indexes, these functions are able to open
relations with a sequence relkind, which is useful to make a distinction
with the other relation kinds. Previously, commands/sequence.c used a
mix of table_{close,open}() and relation_{close,open}() routines when
manipulating sequence relations, so this clarifies the code.
A direct effect of this change is to align the error messages produced
when attempting DDLs for sequences on relations with an unexpected
relkind, like a table or an index with ALTER SEQUENCE, providing an
extra error detail about the relkind of the relation used in the DDL
query.
Author: Michael Paquier
Reviewed-by: Tomas Vondra
Discussion: https://postgr.es/m/ZWlohtKAs0uVVpZ3@paquier.xyz
