when random_page_cost has a small value.  Per Manfred Koizar, though
I didn't use his equation exactly.

> * -Print table names with constraint names in error messages, or make constraint

ALTER TABLE tab ADD COLUMN col SERIAL, but we forgot to install the
dependency between the column and the sequence, so the sequence
would not go away if you dropped the table later.

sequences, as per recent discussion.  All these names are now of the
form table_column_type, with digits added if needed to make them unique.
Default constraint names are chosen to be unique across their whole schema,
not just within the parent object, so as to be more SQL-spec-compatible
and make the information schema views more useful.

Document limitations.

< * Allow hash buckets to fill disk pages, rather than being sparse
> * Pack hash index buckets onto disk pages more efficiently

> * Allow pg_dump to use multiple -t and -n switches

< * Order heap pointers on hash index pages by hash value and ctid
> * Allow hash buckets to fill disk pages, rather than being sparse

Euler Taveira de Oliveira

> * Order heap pointers on hash index pages by hash value and ctid

Serguei A. Mokhov

report from Tom Cook.

As a side effect, cause subscripts in INSERT targetlists to do something
more or less sensible; previously we evaluated such subscripts and then
effectively ignored them.  Another side effect is that UPDATE-ing an
element or slice of an array value that is NULL now produces a non-null
result, namely an array containing just the assigned-to positions.

This cleanup just cleans up a comment.

> * Add ON COMMIT capability to CREATE TABLE AS SELECT

array.

	Basically replaces (*a).b with a->b as it is everywhere else in
	Postgres.

Manfred Koizar

   . rename variables
     . cur_buffer -> dst_buffer
     . ToPage -> dst_page
     . cur_page -> dst_vacpage
   . move variable declarations into block where variable is used
   . various Asserts instead of elog(ERROR, ...)
   . extract functionality from repair_frag() into new routines
     . move_chain_tuple()
     . move_plain_tuple()
     . update_hint_bits()
   . create type ExecContext
   . add comments

Manfred Koizar

code if we are running in a single-byte encoding.  No point in the
extra overhead in that case.

Instead of prohibiting that, put code into ALTER TABLE to reject ALTERs
that would affect other tables' columns.  Eventually we will probably
want to extend ALTER TABLE to actually do something useful here, but
in the meantime it seems wrong to forbid the feature completely just
because ALTER isn't fully baked.