Обсуждение: [HACKERS] ALTER enums (was Re: [COMMITTERS] pgsql: doc: first draft ofPostgres 10 release notes)
[HACKERS] ALTER enums (was Re: [COMMITTERS] pgsql: doc: first draft ofPostgres 10 release notes)
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Alvaro Herrera
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Bruce Momjian wrote: > doc: first draft of Postgres 10 release notes I noticed that this item +<!-- +Author: Tom Lane <tgl@sss.pgh.pa.us> +2016-09-05 [15bc038f9] Relax transactional restrictions on ALTER TYPE ... ADD V +--> +<para> +Reduce locking required for adding values to enum types (Andrew Dunstan, +Tom Lane) +</para> + +<para> +Previously it was impossible to run <command>ALTER TYPE ... ADD VALUE</> in a +transaction block unless the enum type was created in the same block. +Now, only references to uncommitted enum values from other transactions +is prohibited. +</para> does not really explain this change very clearly. (The release note item was slightly changed later, but not in the substance.) It says it's about "locking", but it is certainly not about what we normally call "locking" in Postgres. So, firstly I suggest it doesn't belong in the "Locking" section, but rather it should be under "Utility Commands" instead. Second, I think it should say "Reduce transactional requirements" rather than "reduce locking required". I think there are further changes needed because of commits 175774d2932d and 01c5de88ff2, but that's not what I'm on about here, though discussion on that is welcome. Contrary opinions? -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
On 09/27/2017 06:05 AM, Alvaro Herrera wrote: > Bruce Momjian wrote: >> doc: first draft of Postgres 10 release notes > I noticed that this item > > +<!-- > +Author: Tom Lane <tgl@sss.pgh.pa.us> > +2016-09-05 [15bc038f9] Relax transactional restrictions on ALTER TYPE ... ADD V > +--> > +<para> > +Reduce locking required for adding values to enum types (Andrew Dunstan, > +Tom Lane) > +</para> > + > +<para> > +Previously it was impossible to run <command>ALTER TYPE ... ADD > VALUE</> in a > +transaction block unless the enum type was created in the same block. > +Now, only references to uncommitted enum values from other transactions > +is prohibited. > +</para> > > does not really explain this change very clearly. (The release note item > was slightly changed later, but not in the substance.) It says it's > about "locking", but it is certainly not about what we normally call > "locking" in Postgres. > > So, firstly I suggest it doesn't belong in the "Locking" section, but > rather it should be under "Utility Commands" instead. Second, I think > it should say "Reduce transactional requirements" rather than "reduce > locking required". > > I think there are further changes needed because of commits 175774d2932d > and 01c5de88ff2, but that's not what I'm on about here, though > discussion on that is welcome. > > Contrary opinions? > It looks like this is moot anyway, I think the consensus is to remove the feature and try again in release 11. cheers andrew -- Andrew Dunstan https://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Andrew Dunstan wrote: > It looks like this is moot anyway, I think the consensus is to remove > the feature and try again in release 11. Oh, crap, I didn't realize it had gone badly. Thanks, -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers