Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/10/2 Fabrízio de Royes Mello fabriziome...@gmail.com You're right... the latest proposed patch don't implements it. I'll change the patch and send soon... What is more reasonable? * show a syntax error or * show a message that you can not use the INE with contained objects Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Excerpts from Fabrízio de Royes Mello's message of mié oct 03 09:27:41 -0300 2012: 2012/10/2 Fabrízio de Royes Mello fabriziome...@gmail.com You're right... the latest proposed patch don't implements it. I'll change the patch and send soon... What is more reasonable? * show a syntax error or * show a message that you can not use the INE with contained objects Second one. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/10/3 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Fabrízio de Royes Mello's message of mié oct 03 09:27:41 -0300 2012: 2012/10/2 Fabrízio de Royes Mello fabriziome...@gmail.com You're right... the latest proposed patch don't implements it. I'll change the patch and send soon... What is more reasonable? * show a syntax error or * show a message that you can not use the INE with contained objects Second one. Maybe something like this? ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg(IF NOT EXISTS cannot be used with schema elements), parser_errposition(@9))); -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Excerpts from Fabrízio de Royes Mello's message of mié oct 03 10:11:03 -0300 2012: Maybe something like this? ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg(IF NOT EXISTS cannot be used with schema elements), parser_errposition(@9))); Seems reasonable, but where? Please submit a complete patch. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/10/3 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Fabrízio de Royes Mello's message of mié oct 03 10:11:03 -0300 2012: Maybe something like this? ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg(IF NOT EXISTS cannot be used with schema elements), parser_errposition(@9))); Seems reasonable, but where? Please submit a complete patch. The attached patch implements the behavior we've discussed. If we use IF NOT EXISTS with schema elements then occurs an error like this: [local]:5432 fabrizio@fabrizio=# CREATE SCHEMA IF NOT EXISTS test_schema_1 CREATE TABLE abc ( a serial, b int UNIQUE ); ERROR: IF NOT EXISTS cannot be used with schema elements LINE 1: CREATE SCHEMA IF NOT EXISTS test_schema_1 ^ Time: 0,773 ms Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello create_schema_if_not_exists_v7.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
=?ISO-8859-1?Q?Fabr=EDzio_de_Royes_Mello?= fabriziome...@gmail.com writes: The attached patch implements the behavior we've discussed. OK, I'll pick this up again, since we seem to have consensus on this behavior. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
=?ISO-8859-1?Q?Fabr=EDzio_de_Royes_Mello?= fabriziome...@gmail.com writes: The attached patch implements the behavior we've discussed. Committed with some adjustments, notably repairing the order-of-operations error I complained about before. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Oct 3, 2012, at 4:49 PM, Tom Lane t...@sss.pgh.pa.us wrote: Committed with some adjustments, notably repairing the order-of-operations error I complained about before. Awesome, thanks! David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
The fundamental issue with this patch hasn't been answered sufficiently, I think. Consider the following sequence of commands: create schema if not exists foo create table first (a int); create schema if not exists foo create table second (a int); As far as I can see, with the patch as it currently stands, you would end up with only table first in the schema, which seems very surprising to me. I think this needs more thought, and in any case it needs more comprehensive regression test and documentation (i.e. at least the examples ought to explain what would happen in such cases). -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Excerpts from Volker Grabsch's message of sáb sep 29 06:32:13 -0300 2012: Dickson S. Guedes schrieb: - https://commitfest.postgresql.org/action/patch_view?id=907 The patch is small and implements a new syntax to CREATE SCHEMA that allow the creation of a schema be skipped when IF NOT EXISTS is used. [...] - Should this patch implements others INEs like ADD COLUMN IF NOT EXISTS? If there's still a chance to improve the patch, I'd love to see the following INEs implemented. Several real-world database upgrade scripts would benefit from those: I don't see that this patch is responsible for such new commands. If you want them, feel free to submit separate patches for them (or have someone else do it for you). But see the thread starting at http://archives.postgresql.org/message-id/467881.79137.qm%40web27104.mail.ukl.yahoo.com -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Oct 2, 2012, at 12:08 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: create schema if not exists foo create table first (a int); create schema if not exists foo create table second (a int); As far as I can see, with the patch as it currently stands, you would end up with only table first in the schema, which seems very surprising to me. Yeah, I think the second should die. CINE should only work if there are no other objects created as part of the statement, IMHO. Best, David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Excerpts from David E. Wheeler's message of mar oct 02 16:16:37 -0300 2012: On Oct 2, 2012, at 12:08 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: create schema if not exists foo create table first (a int); create schema if not exists foo create table second (a int); As far as I can see, with the patch as it currently stands, you would end up with only table first in the schema, which seems very surprising to me. Yeah, I think the second should die. CINE should only work if there are no other objects created as part of the statement, IMHO. Well, if that's the rationale then you end up with no schema foo at all (i.e. both die), which seems even more surprising (though I admit it has the advantage of being a simple rule to document.) How about call this for precedent: mkdir -p /tmp/foo/bar mkdir -p /tmp/foo/baz In this case you end up with directory foo and at least two subdirs in it, bar and baz. This works even if /tmp/foo existed previously and even if there was some other stuff in it. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Oct 2, 2012, at 12:30 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: How about call this for precedent: mkdir -p /tmp/foo/bar mkdir -p /tmp/foo/baz In this case you end up with directory foo and at least two subdirs in it, bar and baz. This works even if /tmp/foo existed previously and even if there was some other stuff in it. Well, what about this, then? create schema if not exists foo create table second (a int); create schema if not exists foo create table second (b int); David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Alvaro Herrera alvhe...@2ndquadrant.com writes: Excerpts from David E. Wheeler's message of mar oct 02 16:16:37 -0300 2012: On Oct 2, 2012, at 12:08 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: create schema if not exists foo create table first (a int); create schema if not exists foo create table second (a int); As far as I can see, with the patch as it currently stands, you would end up with only table first in the schema, which seems very surprising to me. Yeah, I think the second should die. CINE should only work if there are no other objects created as part of the statement, IMHO. Well, if that's the rationale then you end up with no schema foo at all (i.e. both die), which seems even more surprising (though I admit it has the advantage of being a simple rule to document.) I think we should just disallow putting any contained objects in the statement when IF NOT EXISTS is used. It's simple to understand, simple to document and implement, and I think it covers all the sane use-cases anyway. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Excerpts from David E. Wheeler's message of mar oct 02 16:37:30 -0300 2012: On Oct 2, 2012, at 12:30 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: How about call this for precedent: mkdir -p /tmp/foo/bar mkdir -p /tmp/foo/baz In this case you end up with directory foo and at least two subdirs in it, bar and baz. This works even if /tmp/foo existed previously and even if there was some other stuff in it. Well, what about this, then? create schema if not exists foo create table second (a int); create schema if not exists foo create table second (b int); Yes, exactly -- what about this case? This is precisely the reason we don't have CREATE TABLE IF NOT EXISTS. I don't know what the best answer is. Most people seem to think that the answer ought to be that you end up with a single column second.a, and the second command errors out. So if you do this: create schema if not exists foo create table first (a int); create schema if not exists foo create table first (b int), create table second (a int); you end up with *only* the first table, because the second command errors out when the first table is observed to exist. Now, what if you were to do this instead: create schema if not exists foo create table if not exists first (a int); create schema if not exists foo create table if not exists first (b int), create table if not exists second (a int); The you end up with first.a and second.a. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Oct 2, 2012, at 12:48 PM, Tom Lane t...@sss.pgh.pa.us wrote: I think we should just disallow putting any contained objects in the statement when IF NOT EXISTS is used. It's simple to understand, simple to document and implement, and I think it covers all the sane use-cases anyway. +1 David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On 10/02/2012 03:48 PM, Tom Lane wrote: Alvaro Herrera alvhe...@2ndquadrant.com writes: Excerpts from David E. Wheeler's message of mar oct 02 16:16:37 -0300 2012: On Oct 2, 2012, at 12:08 PM, Alvaro Herrera alvhe...@2ndquadrant.com wrote: create schema if not exists foo create table first (a int); create schema if not exists foo create table second (a int); As far as I can see, with the patch as it currently stands, you would end up with only table first in the schema, which seems very surprising to me. Yeah, I think the second should die. CINE should only work if there are no other objects created as part of the statement, IMHO. Well, if that's the rationale then you end up with no schema foo at all (i.e. both die), which seems even more surprising (though I admit it has the advantage of being a simple rule to document.) I think we should just disallow putting any contained objects in the statement when IF NOT EXISTS is used. It's simple to understand, simple to document and implement, and I think it covers all the sane use-cases anyway. I thought we'd already agreed on this. +1. cheers andrew -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Excerpts from Andrew Dunstan's message of mar oct 02 17:24:38 -0300 2012: On 10/02/2012 03:48 PM, Tom Lane wrote: Alvaro Herrera alvhe...@2ndquadrant.com writes: Well, if that's the rationale then you end up with no schema foo at all (i.e. both die), which seems even more surprising (though I admit it has the advantage of being a simple rule to document.) I think we should just disallow putting any contained objects in the statement when IF NOT EXISTS is used. It's simple to understand, simple to document and implement, and I think it covers all the sane use-cases anyway. I thought we'd already agreed on this. Well, it's not what the latest proposed patch implements. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/10/2 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Andrew Dunstan's message of mar oct 02 17:24:38 -0300 2012: On 10/02/2012 03:48 PM, Tom Lane wrote: Alvaro Herrera alvhe...@2ndquadrant.com writes: Well, if that's the rationale then you end up with no schema foo at all (i.e. both die), which seems even more surprising (though I admit it has the advantage of being a simple rule to document.) I think we should just disallow putting any contained objects in the statement when IF NOT EXISTS is used. It's simple to understand, simple to document and implement, and I think it covers all the sane use-cases anyway. I thought we'd already agreed on this. Well, it's not what the latest proposed patch implements. You're right... the latest proposed patch don't implements it. I'll change the patch and send soon... Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
This case points to a weakness in many programming languages, not having a clear ifof (if and only if) versus if construction. The sane use case for create schema foo if not exists object is for building a database dynamically, where several points may be the first to put a table in a schema, and schemas should not be created if there are no objects. The create/search/drop design pattern having its own problems. Thus the construction should default to one behavior, and have an option for the second. e.g. create schema foo if not exists (will not be done if foo existed) create schema foo if not exists FORCE (will be done even if foo existed) This would even allow for mixed e.g. create schema foo if not exists (tables that should be created once and not again) FORCE (objects routine will add if the schema does) On Oct 2, 2012, at 6:33 PM, Fabrízio de Royes Mello wrote: 2012/10/2 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Andrew Dunstan's message of mar oct 02 17:24:38 -0300 2012: On 10/02/2012 03:48 PM, Tom Lane wrote: Alvaro Herrera alvhe...@2ndquadrant.com writes: Well, if that's the rationale then you end up with no schema foo at all (i.e. both die), which seems even more surprising (though I admit it has the advantage of being a simple rule to document.) I think we should just disallow putting any contained objects in the statement when IF NOT EXISTS is used. It's simple to understand, simple to document and implement, and I think it covers all the sane use-cases anyway. I thought we'd already agreed on this. Well, it's not what the latest proposed patch implements. You're right... the latest proposed patch don't implements it. I'll change the patch and send soon... Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Dickson S. Guedes schrieb: - https://commitfest.postgresql.org/action/patch_view?id=907 The patch is small and implements a new syntax to CREATE SCHEMA that allow the creation of a schema be skipped when IF NOT EXISTS is used. [...] - Should this patch implements others INEs like ADD COLUMN IF NOT EXISTS? If there's still a chance to improve the patch, I'd love to see the following INEs implemented. Several real-world database upgrade scripts would benefit from those: 1) CREATE [ TEMPORARY | TEMP ] SEQUENCE [ IF NOT EXISTS ] name ... 2) ALTER TABLE ... ADD [ COLUMN ] [ IF NOT EXISTS ] column_name ... 3) CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ] [ IF NOT EXISTS ] [ name ] ON ... Regards, Volker -- Volker Grabsch ---(())--- -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Sep 21, 2012, at 10:59 AM, Tom Lane t...@sss.pgh.pa.us wrote: I don't believe this has been thought through nearly carefully enough. If CREATE SCHEMA created a schema and nothing more, then the proposed implementation would probably be fine. But per spec, CREATE SCHEMA can specify not only creating the schema but a whole bunch of objects within the schema. As coded, if the schema exists then creation of the specified sub-objects is just skipped, regardless of whether they exist or not. I doubt that this is really sane behavior. Would the principle of least astonishment dictate that the IF NOT EXISTS option apply implicitly to each sub-object as well? (If so, we'd have to extend everything that can appear in OptSchemaEltList; most of those commands don't have IF NOT EXISTS options today.) I had no idea about that functionality. Seems very strange. A possible compromise is to allow the IF NOT EXISTS option only without a schema-element list, which I suspect is the only use-case David had in mind to start with anyway. Yes, true. The existing patch added the check in a pretty randomly chosen spot too, with one bad consequence being that if the schema already exists then it will fall out with the wrong user ID in effect, creating a security bug. But I'm not entirely sure where to put the check instead. Should we put it before or after the permissions checks --- that is, should IF NOT EXISTS require that you would have had permission to create the schema? Or, if the schema does exist, should we just call it good anyway? I'm too lazy to look at how other INE options resolved this question, but it seems like we ought to be consistent. Agreed. But if it already exists, where does it currently die? ISTM that would be the point to check, if possible. Also, the AUTHORIZATION clause of CREATE SCHEMA creates an aspect of all this that doesn't exist for any other kind of CREATE command, namely that the object might have been requested to be created under some other user id. For instance, supposing that we were to go forward with trying to create sub-objects, but the ownership of the existing schema is different from what's implied or specified by CREATE SCHEMA, should the sub-objects be (attempted to be) created as owned by that user instead? Perhaps not, but I'm not at all sure. I tend to think that if the schema exists, there should be no attempt to create the sub-objects. Seems the least astonishing to me. Best, David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Dickson S. Guedes lis...@guedesoft.net writes: I reviewed this v5 of patch: - https://commitfest.postgresql.org/action/patch_view?id=907 The patch is small and implements a new syntax to CREATE SCHEMA that allow the creation of a schema be skipped when IF NOT EXISTS is used. I don't believe this has been thought through nearly carefully enough. If CREATE SCHEMA created a schema and nothing more, then the proposed implementation would probably be fine. But per spec, CREATE SCHEMA can specify not only creating the schema but a whole bunch of objects within the schema. As coded, if the schema exists then creation of the specified sub-objects is just skipped, regardless of whether they exist or not. I doubt that this is really sane behavior. Would the principle of least astonishment dictate that the IF NOT EXISTS option apply implicitly to each sub-object as well? (If so, we'd have to extend everything that can appear in OptSchemaEltList; most of those commands don't have IF NOT EXISTS options today.) This is somewhat connected to our previous arguments about whether CINE ought to try to make any guarantees about whether the existing object is at all like the object that would have been created if the statement executed successfully. I realize that the existing statements that have an INE option have entirely blown off this concern, but I still think that it's a question that ought to be considered, particularly for objects that have separately creatable sub-structure. A possible compromise is to allow the IF NOT EXISTS option only without a schema-element list, which I suspect is the only use-case David had in mind to start with anyway. The existing patch added the check in a pretty randomly chosen spot too, with one bad consequence being that if the schema already exists then it will fall out with the wrong user ID in effect, creating a security bug. But I'm not entirely sure where to put the check instead. Should we put it before or after the permissions checks --- that is, should IF NOT EXISTS require that you would have had permission to create the schema? Or, if the schema does exist, should we just call it good anyway? I'm too lazy to look at how other INE options resolved this question, but it seems like we ought to be consistent. Also, the AUTHORIZATION clause of CREATE SCHEMA creates an aspect of all this that doesn't exist for any other kind of CREATE command, namely that the object might have been requested to be created under some other user id. For instance, supposing that we were to go forward with trying to create sub-objects, but the ownership of the existing schema is different from what's implied or specified by CREATE SCHEMA, should the sub-objects be (attempted to be) created as owned by that user instead? Perhaps not, but I'm not at all sure. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Sat, Sep 22, 2012 at 3:06 AM, David E. Wheeler da...@justatheory.comwrote: On Sep 21, 2012, at 10:59 AM, Tom Lane t...@sss.pgh.pa.us wrote: I don't believe this has been thought through nearly carefully enough. If CREATE SCHEMA created a schema and nothing more, then the proposed implementation would probably be fine. But per spec, CREATE SCHEMA can specify not only creating the schema but a whole bunch of objects within the schema. As coded, if the schema exists then creation of the specified sub-objects is just skipped, regardless of whether they exist or not. I doubt that this is really sane behavior. Would the principle of least astonishment dictate that the IF NOT EXISTS option apply implicitly to each sub-object as well? (If so, we'd have to extend everything that can appear in OptSchemaEltList; most of those commands don't have IF NOT EXISTS options today.) I had no idea about that functionality. Seems very strange. Isn't it this SQL? CREATE SCHEMA foo CREATE TABLE aa (a int) CREATE TABLE bb (b int); -- Michael Paquier http://michael.otacoo.com
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/9/21 David E. Wheeler da...@justatheory.com
On Sep 21, 2012, at 10:59 AM, Tom Lane t...@sss.pgh.pa.us wrote:
I don't believe this has been thought through nearly carefully enough.
If CREATE SCHEMA created a schema and nothing more, then the proposed
implementation would probably be fine. But per spec, CREATE SCHEMA
can specify not only creating the schema but a whole bunch of objects
within the schema. As coded, if the schema exists then creation of
the specified sub-objects is just skipped, regardless of whether they
exist or not. I doubt that this is really sane behavior. Would the
principle of least astonishment dictate that the IF NOT EXISTS option
apply implicitly to each sub-object as well? (If so, we'd have to
extend everything that can appear in OptSchemaEltList; most of those
commands don't have IF NOT EXISTS options today.)
I had no idea about that functionality. Seems very strange.
I completely forgot this functionality. The example above is from our docs
[1]:
CREATE SCHEMA hollywood
CREATE TABLE films (title text, release date, awards text[])
CREATE VIEW winners AS
SELECT title, release FROM films WHERE awards IS NOT NULL;
The CREATE SCHEMA statement accepts another CREATE commands (CREATE
{TABLE | VIEW | INDEX | SEQUENCE | TRIGGER}), and the current patch do not
consider this options.
A possible compromise is to allow the IF NOT EXISTS option only without
a schema-element list, which I suspect is the only use-case David had in
mind to start with anyway.
Yes, true.
Ok.
The existing patch added the check in a pretty randomly chosen spot too,
with one bad consequence being that if the schema already exists then it
will fall out with the wrong user ID in effect, creating a security bug.
But I'm not entirely sure where to put the check instead. Should we put
it before or after the permissions checks --- that is, should IF NOT
EXISTS require that you would have had permission to create the schema?
Or, if the schema does exist, should we just call it good anyway? I'm
too lazy to look at how other INE options resolved this question, but it
seems like we ought to be consistent.
Agreed. But if it already exists, where does it currently die? ISTM that
would be the point to check, if possible.
I change the patch (attached) to skip only the schema creation and execute
others statements...
Also, the AUTHORIZATION clause of CREATE SCHEMA creates an aspect of all
this that doesn't exist for any other kind of CREATE command, namely
that the object might have been requested to be created under some other
user id. For instance, supposing that we were to go forward with trying
to create sub-objects, but the ownership of the existing schema is
different from what's implied or specified by CREATE SCHEMA, should the
sub-objects be (attempted to be) created as owned by that user instead?
Perhaps not, but I'm not at all sure.
I tend to think that if the schema exists, there should be no attempt to
create the sub-objects. Seems the least astonishing to me.
Why don't create sub-objects? I think the INE clause must affect only
CREATE SCHEMA statement, the others must be executed normally. We can
discuss more about it...
[1] http://www.postgresql.org/docs/9.2/interactive/sql-createschema.html
--
Fabrízio de Royes Mello
Consultoria/Coaching PostgreSQL
Blog sobre TI: http://fabriziomello.blogspot.com
Perfil Linkedin: http://br.linkedin.com/in/fabriziomello
Twitter: http://twitter.com/fabriziomello
create_schema_if_not_exists_v6.patch
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Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/27 Dickson S. Guedes lis...@guedesoft.net [...] Two questions: - Should this patch implements others INEs like ADD COLUMN IF NOT EXISTS? If this feature is important I believe we must implement it. Exists several CREATE statements without IF NOT EXISTS option too, so we can discuss more about it and I can implement it in this patch or in another. - Should pg_dump or pg_restore support some kind of flag to use a CREATE SCHEMA IF NOT EXISTS ... instead CREATE SCHEMA ...? I can't imagine a use case for this feature... can you explain more about your idea? Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Aug 28, 2012, at 8:19 AM, Fabrízio de Royes Mello wrote: - Should this patch implements others INEs like ADD COLUMN IF NOT EXISTS? If this feature is important I believe we must implement it. Exists several CREATE statements without IF NOT EXISTS option too, so we can discuss more about it and I can implement it in this patch or in another. I don't think any of them have to be a part of *this* patch. There can be patches for each of them. Probably simpler that way. But then, I am not like to code them, so WTF do I know? :-) David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/28 David E. Wheeler da...@justatheory.com: On Aug 28, 2012, at 8:19 AM, Fabrízio de Royes Mello wrote: - Should this patch implements others INEs like ADD COLUMN IF NOT EXISTS? If this feature is important I believe we must implement it. Exists several CREATE statements without IF NOT EXISTS option too, so we can discuss more about it and I can implement it in this patch or in another. I don't think any of them have to be a part of *this* patch. There can be patches for each of them. Probably simpler that way. Yes, agreed. Other implementations should be in their own distinct patches. BTW, it could be interesting search the archive for past discussions about CINE. I changed the status of this patch to Ready for Committer. Regards, -- Dickson S. Guedes mail/xmpp: gue...@guedesoft.net - skype/twitter: guediz ~ github.com/guedes http://guedesoft.net ~ http://www.postgresql.org.br -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Hello, I reviewed this v5 of patch: - https://commitfest.postgresql.org/action/patch_view?id=907 The patch is small and implements a new syntax to CREATE SCHEMA that allow the creation of a schema be skipped when IF NOT EXISTS is used. It was applied to 483c2c1071c45e275782d33d646c3018f02f9f94 with two hunks offset, was compiled without errors or new warnings and pass all tests, even the tests that covers the expected results for it self. The docs was updated with the information about the expected behavior. I tested against ambiguity, i. e. creating a schema with name 'if' and got the expected results when try to create it if not exists. Two questions: - Should this patch implements others INEs like ADD COLUMN IF NOT EXISTS? - Should pg_dump or pg_restore support some kind of flag to use a CREATE SCHEMA IF NOT EXISTS ... instead CREATE SCHEMA ...? Regards, -- Dickson S. Guedes mail/xmpp: gue...@guedesoft.net - skype/twitter: guediz ~ github.com/guedes http://guedesoft.net ~ http://www.postgresql.org.br create_schema_if_not_exists_v5.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/16 Dickson S. Guedes lis...@guedesoft.net 2012/8/16 Fabrízio de Royes Mello fabriziome...@gmail.com: The attached patch implement this feature: CREATE SCHEMA [ IF NOT EXISTS ] schema_name [ AUTHORIZATION user_name ] [ schema_element [ ... ] ] CREATE SCHEMA [ IF NOT EXISTS ] AUTHORIZATION user_name [ schema_element [ ... ] ] Now, PostgreSQL don't trow an error if we use IF NOT EXISTS in CREATE SCHEMA statement. I started testing this, but I didn't see regression tests for it. Could you write them?. The attached patch contains regression tests for it. Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello create_schema_if_not_exists_v2.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/17 Fabrízio de Royes Mello fabriziome...@gmail.com I started testing this, but I didn't see regression tests for it. Could you write them?. The attached patch contains regression tests for it. Please, don't consider de last patch (v2) because I make a little mistake on create_schema.sgml structure. The attached patch fix that. Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello create_schema_if_not_exists_v3.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
Excerpts from Fabrízio de Royes Mello's message of vie ago 17 09:16:30 -0400 2012: The attached patch contains regression tests for it. I think you're missing support in copyfuncs.c and equalfuncs.c for the new field in the node. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/17 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Fabrízio de Royes Mello's message of vie ago 17 09:16:30 -0400 2012: The attached patch contains regression tests for it. I think you're missing support in copyfuncs.c and equalfuncs.c for the new field in the node. You're completely right, thanks... The attached patch add support for the new field in the node in copyfuncs.c and equalfuncs.c. Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello create_schema_if_not_exists_v4.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/17 Fabrízio de Royes Mello fabriziome...@gmail.com: 2012/8/17 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Fabrízio de Royes Mello's message of vie ago 17 09:16:30 -0400 2012: The attached patch contains regression tests for it. I think you're missing support in copyfuncs.c and equalfuncs.c for the new field in the node. You're completely right, thanks... The attached patch add support for the new field in the node in copyfuncs.c and equalfuncs.c. Maybe I'm missing something but shouldn't it being handled in extension.c too? []s -- Dickson S. Guedes mail/xmpp: gue...@guedesoft.net - skype: guediz http://guedesoft.net - http://www.postgresql.org.br -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/17 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Dickson S. Guedes's message of vie ago 17 10:37:25 -0400 2012: 2012/8/17 Fabrízio de Royes Mello fabriziome...@gmail.com: 2012/8/17 Alvaro Herrera alvhe...@2ndquadrant.com Excerpts from Fabrízio de Royes Mello's message of vie ago 17 09:16:30 -0400 2012: The attached patch contains regression tests for it. I think you're missing support in copyfuncs.c and equalfuncs.c for the new field in the node. You're completely right, thanks... The attached patch add support for the new field in the node in copyfuncs.c and equalfuncs.c. Maybe I'm missing something but shouldn't it being handled in extension.c too? Please be more explicit? I don't know what you mean. Returning conversation to the list. I think he talked about this piece of code: diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c index 8512cdb..e359a9c 100644 --- a/src/backend/commands/extension.c +++ b/src/backend/commands/extension.c @@ -1374,6 +1374,7 @@ CreateExtension(CreateExtensionStmt *stmt) csstmt-schemaname = schemaName; csstmt-authid = NULL; /* will be created by current user */ csstmt-schemaElts = NIL; + csstmt-if_not_exists = false; CreateSchemaCommand(csstmt, NULL); /* Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello create_schema_if_not_exists_v5.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/15 David E. Wheeler da...@justatheory.com On Aug 15, 2012, at 11:31 AM, Fabrízio de Royes Mello wrote: Is there any reason not to add $subject? Would it be difficult? Looking to the source code I think this feature isn't hard to implement... I'm writing a little path to do that and I'll send soon... Cool, thanks! The attached patch implement this feature: CREATE SCHEMA [ IF NOT EXISTS ] schema_name [ AUTHORIZATION user_name ] [ schema_element [ ... ] ] CREATE SCHEMA [ IF NOT EXISTS ] AUTHORIZATION user_name [ schema_element [ ... ] ] Now, PostgreSQL don't trow an error if we use IF NOT EXISTS in CREATE SCHEMA statement. So, I don't know the next steps... Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello create_schema_if_not_exists.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On 08/16/2012 01:36 PM, Fabrízio de Royes Mello wrote: 2012/8/15 David E. Wheeler da...@justatheory.com mailto:da...@justatheory.com On Aug 15, 2012, at 11:31 AM, Fabrízio de Royes Mello wrote: Is there any reason not to add $subject? Would it be difficult? Looking to the source code I think this feature isn't hard to implement... I'm writing a little path to do that and I'll send soon... Cool, thanks! The attached patch implement this feature: CREATE SCHEMA [ IF NOT EXISTS ] schema_name [ AUTHORIZATION user_name ] [ schema_element [ ... ] ] CREATE SCHEMA [ IF NOT EXISTS ] AUTHORIZATION user_name [ schema_element [ ... ] ] Now, PostgreSQL don't trow an error if we use IF NOT EXISTS in CREATE SCHEMA statement. So, I don't know the next steps... Please see http://wiki.postgresql.org/wiki/Developer_FAQ#I_have_developed_a_patch.2C_what_next.3F cheers andrew -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Aug 16, 2012, at 10:36 AM, Fabrízio de Royes Mello wrote: The attached patch implement this feature: CREATE SCHEMA [ IF NOT EXISTS ] schema_name [ AUTHORIZATION user_name ] [ schema_element [ ... ] ] CREATE SCHEMA [ IF NOT EXISTS ] AUTHORIZATION user_name [ schema_element [ ... ] ] Now, PostgreSQL don't trow an error if we use IF NOT EXISTS in CREATE SCHEMA statement. So, I don't know the next steps... Awesome, thanks! Please add it to the next CommitFest: https://commitfest.postgresql.org/action/commitfest_view?id=15 Best, David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/16 David E. Wheeler da...@justatheory.com On Aug 16, 2012, at 10:36 AM, Fabrízio de Royes Mello wrote: The attached patch implement this feature: CREATE SCHEMA [ IF NOT EXISTS ] schema_name [ AUTHORIZATION user_name ] [ schema_element [ ... ] ] CREATE SCHEMA [ IF NOT EXISTS ] AUTHORIZATION user_name [ schema_element [ ... ] ] Now, PostgreSQL don't trow an error if we use IF NOT EXISTS in CREATE SCHEMA statement. So, I don't know the next steps... Awesome, thanks! Please add it to the next CommitFest: https://commitfest.postgresql.org/action/commitfest_view?id=15 Patch added to CommitFest: https://commitfest.postgresql.org/action/patch_view?id=907 Thanks, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/16 Fabrízio de Royes Mello fabriziome...@gmail.com: The attached patch implement this feature: CREATE SCHEMA [ IF NOT EXISTS ] schema_name [ AUTHORIZATION user_name ] [ schema_element [ ... ] ] CREATE SCHEMA [ IF NOT EXISTS ] AUTHORIZATION user_name [ schema_element [ ... ] ] Now, PostgreSQL don't trow an error if we use IF NOT EXISTS in CREATE SCHEMA statement. I started testing this, but I didn't see regression tests for it. Could you write them?. Best. -- Dickson S. Guedes mail/xmpp: gue...@guedesoft.net - skype: guediz http://guedesoft.net - http://www.postgresql.org.br -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] CREATE SCHEMA IF NOT EXISTS
Hackers, Is there any reason not to add $subject? Would it be difficult? Would save me having to write a DO statement every time I needed it (which in migration scripts is fairly often). Thanks, David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
2012/8/15 David E. Wheeler da...@justatheory.com Hackers, Is there any reason not to add $subject? Would it be difficult? Looking to the source code I think this feature isn't hard to implement... I'm writing a little path to do that and I'll send soon... Would save me having to write a DO statement every time I needed it (which in migration scripts is fairly often). I understand your difficulty. Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL Blog sobre TI: http://fabriziomello.blogspot.com Perfil Linkedin: http://br.linkedin.com/in/fabriziomello Twitter: http://twitter.com/fabriziomello
Re: [HACKERS] CREATE SCHEMA IF NOT EXISTS
On Aug 15, 2012, at 11:31 AM, Fabrízio de Royes Mello wrote: Is there any reason not to add $subject? Would it be difficult? Looking to the source code I think this feature isn't hard to implement... I'm writing a little path to do that and I'll send soon... Cool, thanks! David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
