> - Subqueries in the FROM clause can omit aliases
This is great. It never made any sense to me that this was required. For people who are unaware, say you want to understand a table a natural way of doing it might be
select *
from the_table
order by some_metric desc
limit 10
so you'd think you can do the same for queries like
select *
from (
select blah blah blah the rest of the query
) a
order by some_metric desc
limit 10
you need to put the alias 'a' to placate existing postgres even though it's never actually used, which never made any sense to me.
It does the second you want to join to the results of that subquery...this is an optimization that recognizes that the alias is never used and thus can be omitted. Nice QOL feature.
- pg_hba.conf and pg_ident.conf can include other files
- Logical replication apply can use non-PK btree indexes
- Integer literals in non-decimal bases
- Underscores in numeric literals
- Subqueries in the FROM clause can omit aliases
- Addition and subtraction of timestamptz values
- pg_upgrade can override new cluster's locale and encoding