For PostgreSQL >= 9.4 use `gen_random_uuid()` #25395

yawboakye · Jun 13, 2016

Since version 9.4, the PostgreSQL community recommends moving away from
uuid-ossp's UUID generation functions and using pcrypto's
gen_random_uuid() instead. It generates UUID version 4 by default,
which is what everyone tends to use by the way.

These changes use the appropriate UUID function depending on the
underlying PostgreSQL server's version, while maintaining
uuid_generate_v4() in older migrations.

rails-bot · Jun 13, 2016

Thanks for the pull request, and welcome! The Rails team is excited to review your changes, and you should hear from @schneems (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see the contribution instructions for more information.

rafaelfranca · Jun 13, 2016

rafaelfranca reviewed Jun 13, 2016

View changes

rafaelfranca · Jun 13, 2016

Sign in to view

        #
        # Note that setting the UUID primary key default value to +nil+ will
        # require you to assure that you always provide a UUID value before saving
        # a record (as primary keys cannot be +nil+). This might be done via the
        # +SecureRandom.uuid+ method and a +before_save+ callback, for instance.
        def primary_key(name, type = :primary_key, **options)
-          options[:default] = options.fetch(:default, 'uuid_generate_v4()') if type == :uuid
+          if type == :uuid
+            uuid_function = ActiveRecord::Base.connection.supports_pgcrypto_uuid? ? 'gen_random_uuid()' : 'uuid_generate_v4()'


This should be using the connection that it already hold instead of ActiveRecord::Base. Could you change it?

@rafaelfranca Help me out. I can't find which connection to use :(

Seems TableDefinition doesn't have access to a connection. So we should remove the connection check here and pick gen_random_uuid as default. Using ActiveRecord::Base.connection will make this code not support multi connections.

How will that work for users on PostgreSQL 9.3 or lower since gen_random_uuid() is not available to them? Will 9.4 be the minimum required version?

They will have to explicitly tell that they want to use uuid_generate_v4(). I think it is a fair trade off and since it is documented in the changelog users will know it.

rafaelfranca · Jun 13, 2016

rafaelfranca reviewed Jun 13, 2016

View changes

rafaelfranca · Jun 13, 2016

Sign in to view

+    else
+      def test_schema_dumper_for_uuid_primary_key
+        schema = dump_table_schema "pg_uuids"
+        assert_match(/\bcreate_table "pg_uuids", id: :uuid, default: -> { "uuid_generate_v4\(\)" }/, schema)


why is this uuid_generate_v4 not uuid_generate_v1?

Two different columns. The id column, also the primary key, uses the uuid_generate_v1() function while other_uuid uses uuid_generate_v4(). Both are functions in the uuid-ossp extension.

Yeah, but in this test if is using uuid_generate_v4 while in the test above (that should be the same test of this) is using uuid_generate_v1

Thanks for pointing it out. Turns out that test isn't necessary. The test for using gen_random_uuid() when no default is set is done using the pg_uuids_3 table instead.

kamipo · Jun 13, 2016

Duplicate to #21327.

yawboakye · Jun 14, 2016

@kamipo Yes. This PR started life as corrections to @y-yagi's original.

ianks · Jun 30, 2016

@yawboakye Would it be possible to include some information about migrating from uuid-ossp to gen_random_uuid()?

senny · Jul 19, 2016

@ianks I don't think we need to cover migration issues. This is a guide about Active Record not the PostgreSQL database. We should just make sure that we encourage best practices in our examples.

yawboakye · Jul 19, 2016

@senny As this will be my first contribution to Rails, I want to see it through. So please provide feedback and comments to help me improve it. Thanks cc/ @rafaelfranca @maclover7

rafaelfranca · Jul 20, 2016

r? @senny

senny · Jul 20, 2016

senny reviewed Jul 20, 2016

View changes

senny · Jul 20, 2016

Sign in to view

@@ -9,6 +9,10 @@ def connection
  def drop_table(name)
    connection.drop_table name, if_exists: true
  end
+
+  def uuid_function
+    connection.supports_pgcrypto_uuid? ? 'gen_random_uuid()' : 'uuid_generate_v4()'


Wouldn't this mean that upgrading the PG database would case migrations to generate a different result? This might be unexpected at times.

Using a configuration option that's set in an initializer could do the trick. Quite a bit of work for a simple change like this though.

@matthewd any thoughts how we could make this less intrusive?

This is just the test, so it seems fine

matthewd · Aug 22, 2016

matthewd reviewed Aug 22, 2016

View changes

matthewd · Aug 22, 2016

activerecord/lib/active_record/migration/compatibility.rb

+            if options[:id] == :uuid && !options[:default]
+              options[:default] = "uuid_generate_v4()"
+            end
+          end


This needs to be in V5_0

kamipo · Aug 23, 2016

kamipo reviewed Aug 23, 2016

View changes

kamipo · Aug 23, 2016

Sign in to view

+*   For PostgreSQL >= 9.4 use `pgcrypto`'s `gen_random_uuid()` instead of
+    `uuid-ossp`'s UUID generation function.
+
+    *Yaw Boakye*


The original of this PR is #21327. I think that it should be credited the original author.

*Yuji Yaginuma*, *Yaw Boakye*

yawboakye · Nov 23, 2016

@matthewd Hi Matt, looks like we're good to go! 😄

matthewd · Nov 24, 2016

🎉

❤️❤️

prathamesh-sonpatki · Nov 24, 2016

prathamesh-sonpatki reviewed Nov 24, 2016

View changes

prathamesh-sonpatki · Nov 24, 2016

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

        #
        # Note that setting the UUID primary key default value to +nil+ will
        # require you to assure that you always provide a UUID value before saving
        # a record (as primary keys cannot be +nil+). This might be done via the
        # +SecureRandom.uuid+ method and a +before_save+ callback, for instance.
        def primary_key(name, type = :primary_key, **options)
-          options[:default] = options.fetch(:default, "uuid_generate_v4()") if type == :uuid
+          options[:default] = options.fetch(:default, "gen_random_uuid()") if type == :uuid


Shouldn't this check supports_pgcrypto_uuid? and then decide whether to use gen_random_uuid or uuid_generate_v4?

nevermind, I got confused by PR description but checked comment by Rafael.

jcraigk · Dec 7, 2016

jcraigk reviewed Dec 7, 2016

View changes

jcraigk · Dec 7, 2016

activerecord/test/cases/adapters/postgresql/uuid_test.rb

+      ensure
+        drop_table "pg_uuids_4"
+      end
+    else


Unnecessary else?

Removed at #27170.

rails-bot assigned schneems Jun 13, 2016

maclover7 added activerecord PostgreSQL labels Jun 13, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch 2 times, most recently Jul 18, 2016

yawboakye referenced this pull request Jul 18, 2016
Closed
use gen_random_uuid() function from pgcrypto extension in default of uuid primary key (only PostgreSQL >= 9.4) #21327

rails-bot assigned senny and unassigned schneems Jul 20, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Aug 6, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch 2 times, most recently Aug 22, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Aug 25, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Sep 11, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch 2 times, most recently Nov 22, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch to b915b11 Nov 22, 2016

yawboakye closed this Nov 23, 2016

yawboakye reopened this Nov 23, 2016

rafaelfranca merged commit 8556ab5 into rails:master Nov 23, 2016
2 checks passed

2 checks passed

codeclimate Code Climate didn't find any new or fixed issues.
Details

continuous-integration/travis-ci/pr The Travis CI build passed
Details

prathamesh-sonpatki referenced this pull request Nov 24, 2016
Merged
Followup of UUID default extension in the docs #27165

yawboakye deleted the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Nov 24, 2016

kamipo added a commit to kamipo/rails that referenced this pull request Nov 24, 2016

Should test `test_change_column_default` in `PostgresqlUUIDTest`
Follow up to rails#25395.

e683950

kamipo referenced this pull request Nov 24, 2016
Merged
Should test `test_change_column_default` in `PostgresqlUUIDTest` #27172

bdewater referenced this pull request Nov 26, 2016
Closed
compatibility of default uuid generating with postgresql extension #26639

kamipo referenced this pull request Jan 9, 2017
Merged
Fix UUID primary key with default nil in legacy migration #27618

eugeneius referenced this pull request Jun 10, 2017
Merged
Allow `uuid_test.rb` to be loaded on all adapters #29409

rails/rails

Join GitHub today

For PostgreSQL >= 9.4 use `gen_random_uuid()` #25395

Conversation

yawboakye commented Jun 13, 2016

rails-bot assigned schneems Jun 13, 2016

This comment has been minimized.

rails-bot commented Jun 13, 2016

rafaelfranca reviewed Jun 13, 2016 View changes

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

maclover7 added activerecord PostgreSQL labels Jun 13, 2016

rafaelfranca reviewed Jun 13, 2016 View changes

This comment has been minimized.

rafaelfranca Jun 13, 2016 • edited

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

This comment has been minimized.

kamipo commented Jun 13, 2016

This comment has been minimized.

yawboakye commented Jun 14, 2016

This comment has been minimized.

ianks commented Jun 30, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch 2 times, most recently Jul 18, 2016

yawboakye referenced this pull request Jul 18, 2016

This comment has been minimized.

senny commented Jul 19, 2016

This comment has been minimized.

yawboakye commented Jul 19, 2016

This comment has been minimized.

rafaelfranca commented Jul 20, 2016

rails-bot assigned senny and unassigned schneems Jul 20, 2016

senny reviewed Jul 20, 2016 View changes

This comment has been minimized.

This comment has been minimized.

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Aug 6, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch 2 times, most recently Aug 22, 2016

matthewd reviewed Aug 22, 2016 View changes

This comment has been minimized.

kamipo reviewed Aug 23, 2016 View changes

This comment has been minimized.

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Aug 25, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Sep 11, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch 2 times, most recently Nov 22, 2016

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch to b915b11 Nov 22, 2016

yawboakye closed this Nov 23, 2016

yawboakye reopened this Nov 23, 2016

This comment has been minimized.

yawboakye commented Nov 23, 2016

Hide details View details rafaelfranca merged commit 8556ab5 into rails:master Nov 23, 2016 2 checks passed

2 checks passed

This comment has been minimized.

matthewd commented Nov 24, 2016

prathamesh-sonpatki reviewed Nov 24, 2016 View changes

This comment has been minimized.

This comment has been minimized.

prathamesh-sonpatki referenced this pull request Nov 24, 2016

prathamesh-sonpatki added a commit to prathamesh-sonpatki/rails that referenced this pull request Nov 24, 2016

yawboakye deleted the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch Nov 24, 2016

kamipo added a commit to kamipo/rails that referenced this pull request Nov 24, 2016

kamipo referenced this pull request Nov 24, 2016

bdewater referenced this pull request Nov 26, 2016

jcraigk reviewed Dec 7, 2016 View changes

This comment has been minimized.

This comment has been minimized.

kamipo added a commit to kamipo/rails that referenced this pull request Jan 9, 2017

kamipo referenced this pull request Jan 9, 2017

eugeneius referenced this pull request Jun 10, 2017

rafaelfranca reviewed Jun 13, 2016

View changes

rafaelfranca reviewed Jun 13, 2016

View changes

rafaelfranca Jun 13, 2016 •

edited

senny reviewed Jul 20, 2016

View changes

matthewd reviewed Aug 22, 2016

View changes

kamipo reviewed Aug 23, 2016

View changes

yawboakye force-pushed the yawboakye:use_gen_random_uuid_from_pgcrypto_extension branch to `b915b11` Nov 22, 2016

rafaelfranca merged commit `8556ab5` into rails:master Nov 23, 2016
2 checks passed

prathamesh-sonpatki reviewed Nov 24, 2016

View changes

jcraigk reviewed Dec 7, 2016

View changes