Change http postgresql.org links to https [ci skip]

It seems that it accepts only HTTPS connections.
Ref: postgres/postgres@7f77cbd

activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb

@@ -227,7 +227,7 @@ def supports_statement_cache? # :nodoc:
       # You should consult the documentation for your database to understand the
       # semantics of these different levels:
       #
-      # * http://www.postgresql.org/docs/current/static/transaction-iso.html
+      # * https://www.postgresql.org/docs/current/static/transaction-iso.html
       # * https://dev.mysql.com/doc/refman/5.7/en/set-transaction.html
       #
       # An ActiveRecord::TransactionIsolationError will be raised if:

activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb

@@ -224,7 +224,7 @@ def drop_schema(schema_name, options = {})
 
         # Sets the schema search path to a string of comma-separated schema names.
         # Names beginning with $ have to be quoted (e.g. $user => '$user').
-        # See: http://www.postgresql.org/docs/current/static/ddl-schemas.html
+        # See: https://www.postgresql.org/docs/current/static/ddl-schemas.html
         #
         # This should be not be called manually but set in database.yml.
         def schema_search_path=(schema_csv)

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -64,11 +64,11 @@ module ConnectionAdapters
     #   defaults to true.
     #
     # Any further options are used as connection parameters to libpq. See
-    # http://www.postgresql.org/docs/current/static/libpq-connect.html for the
+    # https://www.postgresql.org/docs/current/static/libpq-connect.html for the
     # list of parameters.
     #
     # In addition, default connection parameters of libpq can be set per environment variables.
-    # See http://www.postgresql.org/docs/current/static/libpq-envars.html .
+    # See https://www.postgresql.org/docs/current/static/libpq-envars.html .
     class PostgreSQLAdapter < AbstractAdapter
       ADAPTER_NAME = "PostgreSQL".freeze
 
@@ -393,7 +393,7 @@ def default_index_type?(index) # :nodoc:
 
       private
 
-        # See http://www.postgresql.org/docs/current/static/errcodes-appendix.html
+        # See https://www.postgresql.org/docs/current/static/errcodes-appendix.html
         VALUE_LIMIT_VIOLATION = "22001"
         NUMERIC_VALUE_OUT_OF_RANGE = "22003"
         NOT_NULL_VIOLATION    = "23502"
@@ -713,7 +713,7 @@ def configure_connection
           end
 
           # SET statements from :variables config hash
-          # http://www.postgresql.org/docs/current/static/sql-set.html
+          # https://www.postgresql.org/docs/current/static/sql-set.html
           variables = @config[:variables] || {}
           variables.map do |k, v|
             if v == ":default" || v == :default

activerecord/lib/active_record/errors.rb

@@ -315,7 +315,7 @@ class TransactionIsolationError < ActiveRecordError
   #
   # See the following:
   #
-  # * http://www.postgresql.org/docs/current/static/transaction-iso.html
+  # * https://www.postgresql.org/docs/current/static/transaction-iso.html
   # * https://dev.mysql.com/doc/refman/5.7/en/error-messages-server.html#error_er_lock_deadlock
   class TransactionRollbackError < StatementInvalid
   end

activerecord/lib/active_record/locking/pessimistic.rb

@@ -54,7 +54,7 @@ module Locking
     #
     # Database-specific information on row locking:
     #   MySQL: http://dev.mysql.com/doc/refman/5.7/en/innodb-locking-reads.html
-    #   PostgreSQL: http://www.postgresql.org/docs/current/interactive/sql-select.html#SQL-FOR-UPDATE-SHARE
+    #   PostgreSQL: https://www.postgresql.org/docs/current/interactive/sql-select.html#SQL-FOR-UPDATE-SHARE
     module Pessimistic
       # Obtain a row lock on this record. Reloads the record to obtain the requested
       # lock. Pass an SQL locking clause to append the end of the SELECT statement

guides/source/active_record_postgresql.md

@@ -29,8 +29,8 @@ that are supported by the PostgreSQL adapter.
 
 ### Bytea
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-binary.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-binarystring.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-binary.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-binarystring.html)
 
 ```ruby
 # db/migrate/20140207133952_create_documents.rb
@@ -49,8 +49,8 @@ Document.create payload: data
 
 ### Array
 
-* [type definition](http://www.postgresql.org/docs/current/static/arrays.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-array.html)
+* [type definition](https://www.postgresql.org/docs/current/static/arrays.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-array.html)
 
 ```ruby
 # db/migrate/20140207133952_create_books.rb
@@ -83,8 +83,8 @@ Book.where("array_length(ratings, 1) >= 3")
 
 ### Hstore
 
-* [type definition](http://www.postgresql.org/docs/current/static/hstore.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/hstore.html#AEN179902)
+* [type definition](https://www.postgresql.org/docs/current/static/hstore.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/hstore.html#AEN179902)
 
 NOTE: You need to enable the `hstore` extension to use hstore.
 
@@ -116,8 +116,8 @@ Profile.where("settings->'color' = ?", "yellow")
 
 ### JSON and JSONB
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-json.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-json.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-json.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-json.html)
 
 ```ruby
 # db/migrate/20131220144913_create_events.rb
@@ -147,8 +147,8 @@ Event.where("payload->>'kind' = ?", "user_renamed")
 
 ### Range Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/rangetypes.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-range.html)
+* [type definition](https://www.postgresql.org/docs/current/static/rangetypes.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-range.html)
 
 This type is mapped to Ruby [`Range`](http://www.ruby-doc.org/core-2.2.2/Range.html) objects.
 
@@ -182,7 +182,7 @@ event.ends_at # => Thu, 13 Feb 2014
 
 ### Composite Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/rowtypes.html)
+* [type definition](https://www.postgresql.org/docs/current/static/rowtypes.html)
 
 Currently there is no special support for composite types. They are mapped to
 normal text columns:
@@ -222,7 +222,7 @@ contact.save!
 
 ### Enumerated Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-enum.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-enum.html)
 
 Currently there is no special support for enumerated types. They are mapped as
 normal text columns:
@@ -260,7 +260,7 @@ article.status = "published"
 article.save!
 ```
 
-To add a new value before/after existing one you should use [ALTER TYPE](http://www.postgresql.org/docs/current/static/sql-altertype.html):
+To add a new value before/after existing one you should use [ALTER TYPE](https://www.postgresql.org/docs/current/static/sql-altertype.html):
 
 ```ruby
 # db/migrate/20150720144913_add_new_state_to_articles.rb
@@ -274,7 +274,7 @@ def up
 end
 ```
 
-NOTE: ENUM values can't be dropped currently. You can read why [here](http://www.postgresql.org/message-id/29F36C7C98AB09499B1A209D48EAA615B7653DBC8A@mail2a.alliedtesting.com).
+NOTE: ENUM values can't be dropped currently. You can read why [here](https://www.postgresql.org/message-id/29F36C7C98AB09499B1A209D48EAA615B7653DBC8A@mail2a.alliedtesting.com).
 
 Hint: to show all the values of the all enums you have, you should call this query in `bin/rails db` or `psql` console:
 
@@ -289,9 +289,9 @@ SELECT n.nspname AS enum_schema,
 
 ### UUID
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-uuid.html)
-* [pgcrypto generator function](http://www.postgresql.org/docs/current/static/pgcrypto.html#AEN182570)
-* [uuid-ossp generator functions](http://www.postgresql.org/docs/current/static/uuid-ossp.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-uuid.html)
+* [pgcrypto generator function](https://www.postgresql.org/docs/current/static/pgcrypto.html#AEN182570)
+* [uuid-ossp generator functions](https://www.postgresql.org/docs/current/static/uuid-ossp.html)
 
 NOTE: You need to enable the `pgcrypto` (only PostgreSQL >= 9.4) or `uuid-ossp`
 extension to use uuid.
@@ -340,8 +340,8 @@ See [this section](#uuid-primary-keys) for more details on using UUIDs as primar
 
 ### Bit String Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-bit.html)
-* [functions and operators](http://www.postgresql.org/docs/current/static/functions-bitstring.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-bit.html)
+* [functions and operators](https://www.postgresql.org/docs/current/static/functions-bitstring.html)
 
 ```ruby
 # db/migrate/20131220144913_create_users.rb
@@ -364,7 +364,7 @@ user.save!
 
 ### Network Address Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-net-types.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-net-types.html)
 
 The types `inet` and `cidr` are mapped to Ruby
 [`IPAddr`](http://www.ruby-doc.org/stdlib-2.2.2/libdoc/ipaddr/rdoc/IPAddr.html)
@@ -399,7 +399,7 @@ macbook.address
 
 ### Geometric Types
 
-* [type definition](http://www.postgresql.org/docs/current/static/datatype-geometric.html)
+* [type definition](https://www.postgresql.org/docs/current/static/datatype-geometric.html)
 
 All geometric types, with the exception of `points` are mapped to normal text.
 A point is casted to an array containing `x` and `y` coordinates.
@@ -457,7 +457,7 @@ Document.where("to_tsvector('english', title || ' ' || body) @@ to_tsquery(?)",
 Database Views
 --------------
 
-* [view creation](http://www.postgresql.org/docs/current/static/sql-createview.html)
+* [view creation](https://www.postgresql.org/docs/current/static/sql-createview.html)
 
 Imagine you need to work with a legacy database containing the following table:
 

guides/source/active_record_querying.md

@@ -2045,4 +2045,4 @@ following pointers may be helpful:
 
 * MariaDB: [EXPLAIN](https://mariadb.com/kb/en/mariadb/explain/)
 
-* PostgreSQL: [Using EXPLAIN](http://www.postgresql.org/docs/current/static/using-explain.html)
+* PostgreSQL: [Using EXPLAIN](https://www.postgresql.org/docs/current/static/using-explain.html)

guides/source/active_record_validations.md

@@ -638,7 +638,7 @@ class Holiday < ApplicationRecord
     message: "should happen once per year" }
 end
 ```
-Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.7/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](http://www.postgresql.org/docs/current/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns.
+Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.7/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](https://www.postgresql.org/docs/current/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns.
 
 There is also a `:case_sensitive` option that you can use to define whether the
 uniqueness constraint will be case sensitive or not. This option defaults to