Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
> I thought the syntax came from Berkeley. We can add ALSO if folks like > it. I can't think of cases where we have keywords for both on and off > behavior, and allow a default if the keyword is missing. ALTER TABLE ... DROP CONSTRAINT ... [ RESTRICT | CASCADE ] CREATE TABLE ... [ WITH OIDS | WITHOUT OIDS ] CREATE USER [ CREATEDB | NOCREATEDB ] ... IMHO, from the language design point of view, it seems better if all options have a name. -- Fabien. ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Patch applied. Thanks. --- Fabien COELHO wrote: > > > Shoot me the patch again and I will put in the the queue. Thanks. > > Please find attached (again) the patch I sent. It is against 7.4.1. > If necessary, I can redo the job against current head. > > Have a nice day, > > -- > Fabien Coelho - [EMAIL PROTECTED] Content-Description: [ Attachment, skipping... ] > > ---(end of broadcast)--- > TIP 4: Don't 'kill -9' the postmaster -- Bruce Momjian| http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Jan Wieck wrote: > Bruce Momjian wrote: > > > Jan Wieck wrote: > >> Tom Lane wrote: > >> > >> > Fabien COELHO <[EMAIL PROTECTED]> writes: > >> >> Most of the patch deals with the documentation, which is rather ugly > >> >> because it keeps telling about "INSTEAD" vs "non-INSTEAD" rules, as there > >> >> is no name for the default behavior. I think "ALSO" fixes this issue as it > >> >> clarifies the explanations. > >> > > >> > Hmm ... I find that argument much more convincing than any of the others > >> > ... > >> > > >> > Jan, what do you think? You invented this command's syntax IIRC. > >> > >> I did not. We inherited it from Postgres 4.2. If people think an ALSO > >> keyword will clearify things, what about renaming the whole CREATE RULE > >> into something along the line CREATE QUERY REWRITE MACRO? > > > > Are you saying you don't want ALSO added? > > > > No, I am saying that CREATE RULE is so often misinterpreted to work like > a trigger and when we explain that it is more like Macro expansion > before the query is executed they understand better. CREATE RULE itself > is just vague, with or without ALSO. True. -- Bruce Momjian| http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 7: don't forget to increase your free space map settings
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Bruce Momjian wrote: Jan Wieck wrote: Tom Lane wrote: > Fabien COELHO <[EMAIL PROTECTED]> writes: >> Most of the patch deals with the documentation, which is rather ugly >> because it keeps telling about "INSTEAD" vs "non-INSTEAD" rules, as there >> is no name for the default behavior. I think "ALSO" fixes this issue as it >> clarifies the explanations. > > Hmm ... I find that argument much more convincing than any of the others > ... > > Jan, what do you think? You invented this command's syntax IIRC. I did not. We inherited it from Postgres 4.2. If people think an ALSO keyword will clearify things, what about renaming the whole CREATE RULE into something along the line CREATE QUERY REWRITE MACRO? Are you saying you don't want ALSO added? No, I am saying that CREATE RULE is so often misinterpreted to work like a trigger and when we explain that it is more like Macro expansion before the query is executed they understand better. CREATE RULE itself is just vague, with or without ALSO. Jan -- #==# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #== [EMAIL PROTECTED] # ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Jan Wieck wrote: > Tom Lane wrote: > > > Fabien COELHO <[EMAIL PROTECTED]> writes: > >> Most of the patch deals with the documentation, which is rather ugly > >> because it keeps telling about "INSTEAD" vs "non-INSTEAD" rules, as there > >> is no name for the default behavior. I think "ALSO" fixes this issue as it > >> clarifies the explanations. > > > > Hmm ... I find that argument much more convincing than any of the others > > ... > > > > Jan, what do you think? You invented this command's syntax IIRC. > > I did not. We inherited it from Postgres 4.2. If people think an ALSO > keyword will clearify things, what about renaming the whole CREATE RULE > into something along the line CREATE QUERY REWRITE MACRO? Are you saying you don't want ALSO added? -- Bruce Momjian| http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Tom Lane wrote: Fabien COELHO <[EMAIL PROTECTED]> writes: Most of the patch deals with the documentation, which is rather ugly because it keeps telling about "INSTEAD" vs "non-INSTEAD" rules, as there is no name for the default behavior. I think "ALSO" fixes this issue as it clarifies the explanations. Hmm ... I find that argument much more convincing than any of the others ... Jan, what do you think? You invented this command's syntax IIRC. I did not. We inherited it from Postgres 4.2. If people think an ALSO keyword will clearify things, what about renaming the whole CREATE RULE into something along the line CREATE QUERY REWRITE MACRO? Jan -- #==# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #== [EMAIL PROTECTED] # ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
> Shoot me the patch again and I will put in the the queue. Thanks.
Please find attached (again) the patch I sent. It is against 7.4.1.
If necessary, I can redo the job against current head.
Have a nice day,
--
Fabien Coelho - [EMAIL PROTECTED]*** ./doc/src/sgml/rules.sgml.orig Sun Feb 29 17:35:15 2004
--- ./doc/src/sgml/rules.sgml Sun Feb 29 17:38:45 2004
***
*** 873,879
! They can be INSTEAD or not.
--- 873,879
! They can be INSTEAD or ALSO (default).
***
*** 904,910
CREATE RULE rule_name AS ON event
TO object [WHERE rule_qualification]
! DO [INSTEAD] [action | (actions) | NOTHING];
in mind.
--- 904,910
CREATE RULE rule_name AS ON event
TO object [WHERE rule_qualification]
! DO [ALSO|INSTEAD] [action | (actions) | NOTHING];
in mind.
***
*** 920,926
Initially the query-tree list is empty.
There can be zero (NOTHING key word), one, or multiple actions.
To simplify, we will look at a rule with one action. This rule
! can have a qualification or not and it can be INSTEAD or not.
--- 920,926
Initially the query-tree list is empty.
There can be zero (NOTHING key word), one, or multiple actions.
To simplify, we will look at a rule with one action. This rule
! can have a qualification or not and it can be INSTEAD or
ALSO (default).
***
*** 937,943
! No qualification and not INSTEAD
the query tree from the rule action with the original query
--- 937,943
! No qualification and ALSO
the query tree from the rule action with the original query
***
*** 957,963
! Qualification given and not INSTEAD
the query tree from the rule action with the rule
--- 957,963
! Qualification given and ALSO
the query tree from the rule action with the rule
***
*** 980,986
! Finally, if the rule is not INSTEAD, the unchanged original query
tree is
added to the list. Since only qualified INSTEAD rules already add the
original query tree, we end up with either one or two output query trees
for a rule with one action.
--- 980,986
! Finally, if the rule is ALSO, the unchanged original query tree is
added to the list. Since only qualified INSTEAD rules already add the
original query tree, we end up with either one or two output query trees
for a rule with one action.
***
*** ,1117
! The rule is a qualified non-INSTEAD rule, so the rule system
has to return two query trees: the modified rule action and the original
query tree. In step 1, the range table of the original query is
incorporated into the rule's action query tree. This results in:
--- ,1117
! The rule is a qualified ALSO rule, so the rule system
has to return two query trees: the modified rule action and the original
query tree. In step 1, the range table of the original query is
incorporated into the rule's action query tree. This results in:
***
*** 1190,1196
! That's it. Since the rule is not INSTEAD, we also output the
original query tree. In short, the output from the rule system
is a list of two query trees that correspond to these statements:
--- 1190,1196
! That's it. Since the rule is ALSO, we also output the
original query tree. In short, the output from the rule system
is a list of two query trees that correspond to these statements:
*** ./src/backend/parser/gram.y.origSun Feb 29 17:32:48 2004
--- ./src/backend/parser/gram.y Sun Feb 29 17:33:21 2004
***
*** 327,333
/* ordinary key words in alphabetical order */
%token ABORT_P ABSOLUTE_P ACCESS ACTION ADD AFTER
! AGGREGATE ALL ALTER ANALYSE ANALYZE AND ANY ARRAY AS ASC
ASSERTION ASSIGNMENT AT AUTHORIZATION
BACKWARD BEFORE BEGIN_P BETWEEN BIGINT BINARY BIT
--- 327,333
/* ordinary key words in alphabetical order */
%token ABORT_P ABSOLUTE_P ACCESS ACTION ADD AFTER
! AGGREGATE ALL ALSO ALTER ANALYSE ANALYZE AND ANY ARRAY AS ASC
ASSERTION ASSIGNMENT AT AUTHORIZATION
BACKWARD BEFORE BEGIN_P BETWEEN BIGINT BINARY BIT
***
*** 3529,3534
--- 3529,3535
opt_instead:
INSTEAD
{ $$ = TRUE; }
+ | ALSO
{ $$ = FALS
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Fabien COELHO wrote: > > > I thought the syntax came from Berkeley. We can add ALSO if folks like > > it. I can't think of cases where we have keywords for both on and off > > behavior, and allow a default if the keyword is missing. > > ALTER TABLE ... DROP CONSTRAINT ... [ RESTRICT | CASCADE ] ; > > CREATE TABLE ... [ WITH OIDS | WITHOUT OIDS ] ... ; > > CREATE USER ... [ CREATEDB | NOCREATEDB ] ... ; > > IMHO, from the language design point of view, it seems better if all > options have a name. Makes sense to me now. No one liked the non-INSTEAD rule description, for sure. Shoot me the patch again and I will put in the the queue. Thanks. -- Bruce Momjian| http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
> I thought the syntax came from Berkeley. We can add ALSO if folks like > it. I can't think of cases where we have keywords for both on and off > behavior, and allow a default if the keyword is missing. ALTER TABLE ... DROP CONSTRAINT ... [ RESTRICT | CASCADE ] ; CREATE TABLE ... [ WITH OIDS | WITHOUT OIDS ] ... ; CREATE USER ... [ CREATEDB | NOCREATEDB ] ... ; IMHO, from the language design point of view, it seems better if all options have a name. -- Fabien Coelho - [EMAIL PROTECTED] ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Tom Lane wrote: > Fabien COELHO <[EMAIL PROTECTED]> writes: > > Most of the patch deals with the documentation, which is rather ugly > > because it keeps telling about "INSTEAD" vs "non-INSTEAD" rules, as there > > is no name for the default behavior. I think "ALSO" fixes this issue as it > > clarifies the explanations. > > Hmm ... I find that argument much more convincing than any of the others > ... > > Jan, what do you think? You invented this command's syntax IIRC. I thought the syntax came from Berkeley. We can add ALSO if folks like it. I can't think of cases where we have keywords for both on and off behavior, and allow a default if the keyword is missing. -- Bruce Momjian| http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Fabien COELHO <[EMAIL PROTECTED]> writes: > Most of the patch deals with the documentation, which is rather ugly > because it keeps telling about "INSTEAD" vs "non-INSTEAD" rules, as there > is no name for the default behavior. I think "ALSO" fixes this issue as it > clarifies the explanations. Hmm ... I find that argument much more convincing than any of the others ... Jan, what do you think? You invented this command's syntax IIRC. regards, tom lane ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Dear Bruce, > Is ALSO part of the SQL standard? I can't imagine it is because there > is no rule mention. As RULE is not in the SQL standard, ALSO is sure no part of it. > I guess if we were coding from scratch, we could make the syntax INSTEAD > or ALSO, but at this point, I don't see adding ALSO as a useful change. It depends on what you mean by "useful". It is certainly non essential. I just think it is "user-friendly". It took me some time to understand that rules were appended by default. With the "ALSO" keyword it would have been instantaneous. When I first looked at the syntax with the "INSTEAD" which is optionnal and without alternative, I thought that it was one of those useless keywords that are allowed so as to make SQL more English-like, as the "COLUMN" keyword in the ALTER TABLE syntax. You may argue that I did not read the documentation in depth, but I'm not sure I'm the only one;-) The change is very small (2 lines added, 2 lines changed), and upward compatible, provided that the user has not used ALSO as an object name, what seems rather unlikely IMVVHO. Most of the patch deals with the documentation, which is rather ugly because it keeps telling about "INSTEAD" vs "non-INSTEAD" rules, as there is no name for the default behavior. I think "ALSO" fixes this issue as it clarifies the explanations. Have a nice day, -- Fabien. ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
Re: [PATCHES] "ALSO" keyword to "CREATE RULE" patch
Is ALSO part of the SQL standard? I can't imagine it is because there is no rule mention. I guess if were were coding from scratch, we could make the syntax INSTEAD or ALSO, but at this point, I don't see adding ALSO as a useful change. --- Fabien COELHO wrote: > > Dear patchers, > > Please find attached a small patch to add an optionnal "ALSO" keyword > to the "CREATE RULE" syntax. > > The "ALSO" keyword can be used where "INSTEAD" would be used, > to mean the opposite, i.e. the current default behavior of rules > which adds operations to the current one. IMHO, it makes the > intended behavior much clearer for the basic user (say, me;-). > > CREATE RULE some_table_del AS > ON DELETE TO some_table DO ALSO > ( > DELETE FROM this_other_table WHERE id=old.id; > ); > > Of course, the absence of the "ALSO" keyword preserves the previous > behavior... that is it behaves the same as with the "ALSO" keyword. > > This patch was made against 7.4.1 with the "difforig" script > provided by postgresql. > > It adds "ALSO" keyword in the parser code (two lines), fixes somehow the > documentation and sql help, and modifies four of the "RULE" > test cases to use this keyword instead of the default nothing-ness. > > It validated for me with a "make check". > > Have a nice day, > > -- > Fabien Coelho - [EMAIL PROTECTED] Content-Description: [ Attachment, skipping... ] > > ---(end of broadcast)--- > TIP 8: explain analyze is your friend -- Bruce Momjian| http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup.| Newtown Square, Pennsylvania 19073 ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
