Обсуждение: AW: [HACKERS] triggers, views and rules (not instead)
Since we have so little documentation on the rules, I think we should save
every
little word describing them, so could you simply put the following into a
rules.readme
(undigested is still better than not adding it)
> > Why I like the rewrite system is:
> > 1. select rewrite -- select trigger would be no good (optimizer)
>
> Exactly that's what is done if you create a view. Postgres
> creates a regular table (look at pg_class and into the
> database directory) and then sets up a relation level instead
> rewrite rule on select.
>
> > 2. The client can be really dumb, like MS Access or some other
> > standard ODBC tool
> > which does not know anything about funcs procs and the like
> > (even without using passthrough)
>
> Yupp - the client must not know why and how and where the
> data is left and coming from. But that's true in any case - a
> trigger for each row on insert can do anything different and
> push the data wherever it wants.
>
> > 3. it is a lot more powerful than views
>
> As said - views are only one special rule case in Postgres.
>
> > 4. it allows the optimizer to get involved (this is where triggers
> > fail per definition)
> > 5. once understood it is very easy to use
> > easier than trigger with c stored procedure at least
>
> Optimizing again and again. If the rules aren't instead, the
> querytree get's additional queries for every rule appended.
> Have a table field that references an entry in another table
> and this entry should have a refcount. So on update you must
> decrease the refcount from the old ref and increase it on the
> new. You create two rules so the UPDATE will result in 1
> scan and 2 nestloops with scans inside - really optimized if
> the referenced value doesn't change. And don't think that a
> rule qual of NEW != CURRENT might help - that will result in
> 2 mergejoins where the scanned tuples are compared.
>
I fought that like a windmill, I guess it would be better to kill the
CURRENT keyword
with this meaning alltogether, since it only has the same meaning as the
tablename itself.
I have already crossed it out of my mind and don't miss anything.
I think there should instead be an OLD and NEW keyword
like in triggers:
referencing old as <oldname> new as <newname>
that only reference the tuples in memory.
> BTW, this sample doesn't work currently because the rules
> queries are appended at the end of the querytree, thus the
> decrement scan having the same qual will not find the old
> tuple at all because it's already outdated
> (command_counter_increment between processing the queries).
> Referencing CURRENT in a rule is not what most people think
> it is.
>
> The old 4.2 postgres had a second, instance level rule system
> (prs2 stubs) that fired the rules actions when actually the
> old tuple and the new projected tuple where handy. There you
> could have made also things like 'UPDATE NEW SET a = 4' that
> really modified the in memory tuple in the executors
> expression context. Who the hell removed all that? It was so
> nice :-(
>
Absolutely ! I did cry up when that was done, but nobody responded :-(
Well to be honest Vadim did respond with the trigger code, which made me
feel comfortable again.
> A really simple to write trigger can compare old != new and
> only if send down the other two queries. This time they wont
> be nestloops, they are simple scans. And the trigger can
> arrange that the queries it uses are only parsed on it's
> first of all calls and store the generated execution plans
> permanently for quick execution (look at SPI_prepare).
>
> For the stored C procedures you're totally right. I don't
> like the C functions because it requires postgres superuser
> rights to develop them and thus I created PL/Tcl where joe
> user can hack around without having complete access to the
> whole database (look at src/pl/tcl). And someday after 6.3
> release I'll really start on a plain PL/pgSQL implementation
> that would give a normal user the opportunity to create
> functions and triggers on a high level. There is light at the
> end of the tunnel - hope that it isn't the coming train :-)
>
> >
> > I guess if triggers could also trigger simple select statements, I could
> do
> > most of what I want using triggers except of course the select stuff.
> > But as I said I like the rules system very much, especially after your
> > recent
> > fixes Jan :-) So please stick to supporting all 3: triggers, views and
> > rules. Wow :-)
>
> Well - a trigger cannot build a view. The relation underlying
> the view doesn't contain any tuples and a select trigger will
> never be fired. As long as there is no possibility to return
> tuple sets from non-SQL functions. But a trigger can do
> things like the pg_hide_passwd stuff much more powerful. You
> could define the trigger so that it checks if the user is a
> superuser and overwrite the passwd value only in the case
> where he/she isn't. If fired at the right place it would too
> work for things like the copy command etc.
>
> We must stay with all 3 features. And I will take a look at
> the INSERT ... SELECT view problem really soon as it is a
> rule system problem that breaks views. But this is only the
> SELECT rewriting part of the rule system which I really like
> (optimizable). The other areas (insert, update, delete) of
> the rule system are dangerous and I really think a powerful
> PL/pgSQL language could make them obsolete.
>
> Jan
>
Ok, to sum it up:
1. We need and want the select part of the rewrite rules.
2. for the insert/update/delete rules the old instance rules system
was much more appropriate. TODO: dig up the old code
and merge it with the current trigger Implementation
it must be pretty much the wanted functionality (it
supported sql)
3. the CURRENT keyword in the i/u/d rewrite rules is stupid
and should be disabled
destroyed and burned in hell
4. To stick to the mainstream we should enhance the trigger
syntax,
and forget the rule stuff for i/u/d
create trigger passwd_utr
..........
referencing old as o new as n
for each row (statement, statement, statement, procedure,
...... all PL/pgSQL syntax allowed );
-- with a syntax to modify the new tuple in memory
Andreas
> > > Ok, to sum it up: > 1. We need and want the select part of the rewrite rules. > 2. for the insert/update/delete rules the old instance rules system > was much more appropriate. TODO: dig up the old code > and merge it with the current trigger Implementation > it must be pretty much the wanted functionality (it > supported sql) > 3. the CURRENT keyword in the i/u/d rewrite rules is stupid > and should be disabled > destroyed and burned in hell > 4. To stick to the mainstream we should enhance the trigger > syntax, > and forget the rule stuff for i/u/d > > create trigger passwd_utr > .......... > referencing old as o new as n > for each row (statement, statement, statement, procedure, > ...... all PL/pgSQL syntax allowed ); > -- with a syntax to modify the new tuple in memory This all sounds good to me. Let's do it soon. I like the removal of i/u/d rewrite so we can give people something that will work, and not have all those gray areas of 'it works here, but not here.' -- Bruce Momjian maillist@candle.pha.pa.us
Zeugswetter Andreas SARZ wrote: > Ok, to sum it up: > 1. We need and want the select part of the rewrite rules. Agreed. > 2. for the insert/update/delete rules the old instance rules system > was much more appropriate. TODO: dig up the old code > and merge it with the current trigger Implementation > it must be pretty much the wanted functionality (it > supported sql) ??? Old instance rules system was removed by Jolly & Andrew and so it never supported SQL. I hope that Jan will give us PL/pgSQL soon and it will be used for triggers, without changing current trigger implementation... > 3. the CURRENT keyword in the i/u/d rewrite rules is stupid > and should be disabled, destroyed and burned in hell Agreed, if standard hasn't it. I know that OLD & NEW are in standard, for triggers atleast. > 4. To stick to the mainstream we should enhance the trigger > syntax, and forget the rule stuff for i/u/d Yes. Statement level triggers give the same functionality as rewrite i/u/d rules. We could let them to return something special to skip user' i/u/d itself, isn't it the same as INSTEAD ? Vadim
pl/{perl,pgsql} (was Re: AW: [HACKERS] triggers, views and rules (not instead))
От
Brett McCormick
Дата:
On Sun, 22 February 1998, at 18:26:45, Vadim B. Mikheev wrote: > ??? Old instance rules system was removed by Jolly & Andrew and so > it never supported SQL. I hope that Jan will give us PL/pgSQL soon > and it will be used for triggers, without changing current trigger > implementation... Is develemopment being done for PL/pgSQL? What are peoples ideas for this? I've never used a commercial db before, and the free ones don't usualle have a stored PL language. What sort of things are you guys anticipating? In the writing of PL/perl i've been tempted to give lots of access to the backend internals from perl (why not, it should have all the facilities C function programmers have!) What do you think? Also, as far as argument passing goes: strings & numbers get passed as perl scalars, and most other types get passed as a Posgres::Type object (with methods for conversion etc). Right now I've got a switch block on the type oid and I have many case statements and a few bodies for these conversions. The conversions are hard-coded in the .c file (via the case statements). The only reason any particular input type shows up in perl any particular way (as a scalar (string/int) or Postgres::Type) is because there's a hardcoded case statement for it. Of course, the default is a Postgres::Type. Which means new integer types show up as a Postgres::Type, which could be considered a bad thing. Right now part of what i'm doing is checking the typbyval and then passing that type as an integer scalar (excluding selected types that don't make sense as ints).. Maybe the default case should be the types ouptut function? I hope I make sense.. --brett > > > 3. the CURRENT keyword in the i/u/d rewrite rules is stupid > > and should be disabled, destroyed and burned in hell > > Agreed, if standard hasn't it. I know that OLD & NEW are in standard, > for triggers atleast. > > > 4. To stick to the mainstream we should enhance the trigger > > syntax, and forget the rule stuff for i/u/d > > Yes. Statement level triggers give the same functionality as rewrite > i/u/d rules. We could let them to return something special to skip > user' i/u/d itself, isn't it the same as INSTEAD ? > > Vadim On Sun, 22 February 1998, at 03:33:07, root@bigfoot.speakeasy.org wrote: > X-VM-v5-Data: ([t nil nil nil nil nil nil nil nil] > ["9840" "Sun" "22" "February" "1998" "03:33:07" "-0800" "root@bigfoot.speakeasy.org" "root@bigfoot.speakeasy.org" nil"273" "cron: /etc/dailyback " nil nil nil "2" nil nil (number " " mark "N root@bigfoot.spea Feb 22 273/9840 " thread-indent"\"cron: /etc/dailyback \"\n") nil nil] > nil) > Return-Path: <root@bigfoot.speakeasy.org> > Received: from eve.speakeasy.org (root@eve.speakeasy.org [199.238.226.1]) > by abraxas.scene.com (8.8.8/8.8.5) with ESMTP id DAA16378 > for <brett@work.chicken.org>; Sun, 22 Feb 1998 03:27:21 -0800 > Received: from bigfoot.speakeasy.org (bigfoot.speakeasy.org [199.238.226.54]) by eve.speakeasy.org (8.8.5/8.7.3) with ESMTPid DAA03076; Sun, 22 Feb 1998 03:27:09 -0800 (PST) > From: root@bigfoot.speakeasy.org > Received: (from root@localhost) > by bigfoot.speakeasy.org (8.8.7/8.8.7) id DAA23856; > Sun, 22 Feb 1998 03:33:07 -0800 > Date: Sun, 22 Feb 1998 03:33:07 -0800 > Message-Id: <199802221133.DAA23856@bigfoot.speakeasy.org> > To: root@bigfoot.speakeasy.org > Subject: cron: /etc/dailyback > > ARCHIVING: eve > Begin time: Sun Feb 22 02:14:21 PST 1998 > > DUMP: Date of this level 7 dump: Sun Feb 22 02:14:21 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:26:20 1998 > DUMP: Dumping /dev/rsd3a (/home) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 127906 blocks (62.45MB) on 0.01 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:14:21 1998 > DUMP: Tape rewinding > DUMP: 128490 blocks (62.74MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:17:28 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:31:51 1998 > DUMP: Dumping /dev/rsd3d (/sp1) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 84136 blocks (41.08MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:17:28 1998 > DUMP: Tape rewinding > DUMP: 84222 blocks (41.12MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:20:38 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:38:31 1998 > DUMP: Dumping /dev/rsd2b (/sp2) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 109538 blocks (53.49MB) on 0.01 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:20:38 1998 > DUMP: Tape rewinding > DUMP: 109562 blocks (53.50MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:25:28 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:48:03 1998 > DUMP: Dumping /dev/rsd3e (/sp3) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 121746 blocks (59.45MB) on 0.01 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:25:28 1998 > DUMP: Tape rewinding > DUMP: 121760 blocks (59.45MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:31:30 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:01:18 1998 > DUMP: Dumping /dev/rsd3f (/usr/spool/mail) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 709654 blocks (346.51MB) on 0.04 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: 42.60% done, finished in 0:06 > DUMP: 84.00% done, finished in 0:01 > DUMP: level 7 dump on Sun Feb 22 02:31:30 1998 > DUMP: Tape rewinding > DUMP: 710144 blocks (346.75MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:45:06 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:17:49 1998 > DUMP: Dumping /dev/rsd1a (/usr/local/etc/httpd) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 12236 blocks (5.97MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:45:06 1998 > DUMP: Tape rewinding > DUMP: 12454 blocks (6.08MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:46:59 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:20:04 1998 > DUMP: Dumping /dev/rsd2a (/usr/local) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 576498 blocks (281.49MB) on 0.03 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: 97.17% done, finished in 0:00 > DUMP: level 7 dump on Sun Feb 22 02:46:59 1998 > DUMP: Tape rewinding > DUMP: 577062 blocks (281.77MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:54:18 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:28:41 1998 > DUMP: Dumping /dev/rsd0a (/) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 4658 blocks (2.27MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:54:18 1998 > DUMP: Tape rewinding > DUMP: 4666 blocks (2.28MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:54:28 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:29:03 1998 > DUMP: Dumping /dev/rsd0g (/usr) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 4516 blocks (2.21MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:54:28 1998 > DUMP: Tape rewinding > DUMP: 4512 blocks (2.20MB) on 1 volume > DUMP: DUMP IS DONE > End time: Sun Feb 22 02:54:59 PST 1998 > ARCHIVING: gemini > gemini:/ > > **** bru: execution summary **** > > Started: Sun Feb 22 02:57:09 1998 > Completed: Sun Feb 22 02:57:50 1998 > Archive id: 34f004852588 > Messages: 0 warnings, 0 errors > Archive I/O: 6920 blocks (13840Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 18 files (15 regular, 3 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/usr > > **** bru: execution summary **** > > Started: Sun Feb 22 02:57:50 1998 > Completed: Sun Feb 22 02:58:34 1998 > Archive id: 34f004ae2595 > Messages: 0 warnings, 0 errors > Archive I/O: 10 blocks (20Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 1 files (1 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/usr/local > > **** bru: execution summary **** > > Started: Sun Feb 22 02:58:34 1998 > Completed: Sun Feb 22 03:00:45 1998 > Archive id: 34f004da259d > Messages: 0 warnings, 0 errors > Archive I/O: 22980 blocks (45960Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 419 files (419 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/usr/local/apache/sites > > **** bru: execution summary **** > > Started: Sun Feb 22 03:00:45 1998 > Completed: Sun Feb 22 03:14:29 1998 > Archive id: 34f0055d25ba > Messages: 0 warnings, 0 errors > Archive I/O: 48900 blocks (97800Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 814 files (814 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/mnt/logs > > **** bru: execution summary **** > > Started: Sun Feb 22 03:14:29 1998 > Completed: Sun Feb 22 03:17:10 1998 > Archive id: 34f00895260f > Messages: 0 warnings, 0 errors > Archive I/O: 20 blocks (40Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 5 files (5 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > ARCHIVING: betty > betty:/usr > > **** bru: execution summary **** > > Started: Sun Feb 22 03:15:42 1998 > Completed: Sun Feb 22 03:16:48 1998 > Archive id: 34f008de0465 > Messages: 0 warnings, 0 errors > Archive I/O: 3980 blocks (7960Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 8 files (8 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > betty:/usr/local/samba > > **** bru: execution summary **** > > Started: Sun Feb 22 03:16:48 1998 > Completed: Sun Feb 22 03:17:46 1998 > Archive id: 34f00920046c > Messages: 0 warnings, 0 errors > Archive I/O: 3630 blocks (7260Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 55 files (55 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > ARCHIVING: bigfoot > bigfoot:/var/log0 > > **** bru: execution summary **** > > Started: Sun Feb 22 03:23:13 1998 > Completed: Sun Feb 22 03:30:26 1998 > Archive id: 34f00aa15d23 > Messages: 0 warnings, 0 errors > Archive I/O: 272880 blocks (545760Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 937 files (937 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > ARCHIVING: ella.pscs.org > ella:/var > > **** bru: execution summary **** > > Started: Sun Feb 22 03:27:39 1998 > Completed: Sun Feb 22 03:28:46 1998 > Archive id: 34f00bab08e0 > Messages: 0 warnings, 0 errors > Archive I/O: 13830 blocks (27660Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 58 files (58 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 On Sun, 22 February 1998, at 17:47:07, Vadim B. Mikheev wrote: > X-VM-v5-Data: ([t nil nil nil nil nil nil nil nil] > ["1080" "Sun" "22" "February" "1998" "17:47:07" "+0700" "Vadim B. Mikheev" "vadim@sable.krasnoyarsk.su" nil "32" "Re:[HACKERS] How To free resources used by large object Relations?" nil nil nil "2" nil nil (number " " mark "N VadimB. Mikheev Feb 22 32/1080 " thread-indent "\"Re: [HACKERS] How To free resources used by large object Relations?\"\n")nil nil] > nil) > Return-Path: <owner-pgsql-hackers@hub.org> > Received: from hub.org (hub.org [209.47.148.200]) > by abraxas.scene.com (8.8.8/8.8.5) with ESMTP id CAA16288 > for <brett@work.chicken.org>; Sun, 22 Feb 1998 02:51:20 -0800 > Received: from localhost (majordom@localhost) by hub.org (8.8.8/8.7.5) with SMTP id FAA28144; Sun, 22 Feb 1998 05:45:06-0500 (EST) > Received: by hub.org (TLB v0.10a (1.23 tibbs 1997/01/09 00:29:32)); Sun, 22 Feb 1998 05:44:57 -0500 (EST) > Received: (from majordom@localhost) by hub.org (8.8.8/8.7.5) id FAA28023 for pgsql-hackers-outgoing; Sun, 22 Feb 1998 05:44:49-0500 (EST) > Received: from dune.krasnet.ru (dune.krasnet.ru [193.125.44.86]) by hub.org (8.8.8/8.7.5) with ESMTP id FAA27920 for <pgsql-hackers@postgreSQL.org>;Sun, 22 Feb 1998 05:44:29 -0500 (EST) > Received: from sable.krasnoyarsk.su (dune.krasnet.ru [193.125.44.86]) > by dune.krasnet.ru (8.8.7/8.8.7) with ESMTP id RAA00809; > Sun, 22 Feb 1998 17:47:19 +0700 (KRS) > (envelope-from vadim@sable.krasnoyarsk.su) > Message-ID: <34F0022B.60E59681@sable.krasnoyarsk.su> > Date: Sun, 22 Feb 1998 17:47:07 +0700 > From: "Vadim B. Mikheev" <vadim@sable.krasnoyarsk.su> > Organization: ITTS (Krasnoyarsk) > X-Mailer: Mozilla 4.04 [en] (X11; I; FreeBSD 2.2.5-RELEASE i386) > MIME-Version: 1.0 > To: Maurice Gittens <mgittens@gits.nl> > CC: pgsql-hackers@postgreSQL.org > Subject: Re: [HACKERS] How To free resources used by large object Relations? > References: <018001bd3e01$7651be80$fcf3b2c2@caleb..gits.nl> > Content-Type: text/plain; charset=us-ascii > Content-Transfer-Encoding: 7bit > Sender: owner-pgsql-hackers@hub.org > Precedence: bulk > > Maurice Gittens wrote: > > > > Hi, > > > > I've changed the large object memory managment strategy to ensure that > > each large object has it's own memory context. > > This way I can free all memory for a large object when I lo_close > > is called for it's oid. This seems to work. > > > > I've noticed that the heap_close function used to close the heap used > > by a large object doesn't really do any thing. (It calls RelationClose > > which decrements some reference count). > > > > Somehow I have to free the relation from the cache in the following > > situations: > > 1. In a transaction I must free the stuff when the transaction is > > commited/aborted. > > Backend does it, don't worry. > > > 2. Otherwise it must happen when lo_close is called. > > It seems that you can't remove relation from cache untill > commit/abort, currently: backend uses local cache to unlink > files of relations created in transaction if abort... > We could change relcache.c:RelationPurgeLocalRelation() > to read from pg_class directly... > > But how many LO do you create in single xact ? > Is memory allocated for cache so big ? > > Vadim On Sun, 22 February 1998, at 02:49:37, Eve Arden wrote: > X-VM-v5-Data: ([t nil nil nil nil nil nil nil nil] > ["129" "Sun" "22" "February" "1998" "02:49:37" "-0800" "Eve Arden" "root@eve.speakeasy.org" nil "2" "" nil nil nil"2" nil nil (number " " mark "N Eve Arden Feb 22 2/129 " thread-indent "\"\"\n") nil nil] > nil) > Return-Path: <root@eve.speakeasy.org> > Received: from eve.speakeasy.org (root@eve.speakeasy.org [199.238.226.1]) > by abraxas.scene.com (8.8.8/8.8.5) with ESMTP id CAA16276 > for <brett@work.chicken.org>; Sun, 22 Feb 1998 02:49:50 -0800 > Received: (from root@localhost) by eve.speakeasy.org (8.8.5/8.7.3) id CAA01899; Sun, 22 Feb 1998 02:49:37 -0800 (PST) > Date: Sun, 22 Feb 1998 02:49:37 -0800 (PST) > From: Eve Arden <root@eve.speakeasy.org> > Message-Id: <199802221049.CAA01899@eve.speakeasy.org> > > # Checking accounts from NIS. > >--WARN-- [acc001w] Login ID a-ron is disabled, but still has a valid shell (/usr/local/bin/tcsh).
pl/{perl,pgsql} (was Re: AW: [HACKERS] triggers, views and rules (not instead))
От
Brett McCormick
Дата:
On Sun, 22 February 1998, at 18:26:45, Vadim B. Mikheev wrote: > ??? Old instance rules system was removed by Jolly & Andrew and so > it never supported SQL. I hope that Jan will give us PL/pgSQL soon > and it will be used for triggers, without changing current trigger > implementation... Is develemopment being done for PL/pgSQL? What are peoples ideas for this? I've never used a commercial db before, and the free ones don't usualle have a stored PL language. What sort of things are you guys anticipating? In the writing of PL/perl i've been tempted to give lots of access to the backend internals from perl (why not, it should have all the facilities C function programmers have!) What do you think? Also, as far as argument passing goes: strings & numbers get passed as perl scalars, and most other types get passed as a Posgres::Type object (with methods for conversion etc). Right now I've got a switch block on the type oid and I have many case statements and a few bodies for these conversions. The conversions are hard-coded in the .c file (via the case statements). The only reason any particular input type shows up in perl any particular way (as a scalar (string/int) or Postgres::Type) is because there's a hardcoded case statement for it. Of course, the default is a Postgres::Type. Which means new integer types show up as a Postgres::Type, which could be considered a bad thing. Right now part of what i'm doing is checking the typbyval and then passing that type as an integer scalar (excluding selected types that don't make sense as ints).. Maybe the default case should be the types ouptut function? I hope I make sense.. --brett > > > 3. the CURRENT keyword in the i/u/d rewrite rules is stupid > > and should be disabled, destroyed and burned in hell > > Agreed, if standard hasn't it. I know that OLD & NEW are in standard, > for triggers atleast. > > > 4. To stick to the mainstream we should enhance the trigger > > syntax, and forget the rule stuff for i/u/d > > Yes. Statement level triggers give the same functionality as rewrite > i/u/d rules. We could let them to return something special to skip > user' i/u/d itself, isn't it the same as INSTEAD ? > > Vadim On Sun, 22 February 1998, at 03:33:07, root@bigfoot.speakeasy.org wrote: > X-VM-v5-Data: ([t nil nil nil nil nil nil nil nil] > ["9840" "Sun" "22" "February" "1998" "03:33:07" "-0800" "root@bigfoot.speakeasy.org" "root@bigfoot.speakeasy.org" nil"273" "cron: /etc/dailyback " nil nil nil "2" nil nil (number " " mark "N root@bigfoot.spea Feb 22 273/9840 " thread-indent"\"cron: /etc/dailyback \"\n") nil nil] > nil) > Return-Path: <root@bigfoot.speakeasy.org> > Received: from eve.speakeasy.org (root@eve.speakeasy.org [199.238.226.1]) > by abraxas.scene.com (8.8.8/8.8.5) with ESMTP id DAA16378 > for <brett@work.chicken.org>; Sun, 22 Feb 1998 03:27:21 -0800 > Received: from bigfoot.speakeasy.org (bigfoot.speakeasy.org [199.238.226.54]) by eve.speakeasy.org (8.8.5/8.7.3) with ESMTPid DAA03076; Sun, 22 Feb 1998 03:27:09 -0800 (PST) > From: root@bigfoot.speakeasy.org > Received: (from root@localhost) > by bigfoot.speakeasy.org (8.8.7/8.8.7) id DAA23856; > Sun, 22 Feb 1998 03:33:07 -0800 > Date: Sun, 22 Feb 1998 03:33:07 -0800 > Message-Id: <199802221133.DAA23856@bigfoot.speakeasy.org> > To: root@bigfoot.speakeasy.org > Subject: cron: /etc/dailyback > > ARCHIVING: eve > Begin time: Sun Feb 22 02:14:21 PST 1998 > > DUMP: Date of this level 7 dump: Sun Feb 22 02:14:21 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:26:20 1998 > DUMP: Dumping /dev/rsd3a (/home) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 127906 blocks (62.45MB) on 0.01 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:14:21 1998 > DUMP: Tape rewinding > DUMP: 128490 blocks (62.74MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:17:28 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:31:51 1998 > DUMP: Dumping /dev/rsd3d (/sp1) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 84136 blocks (41.08MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:17:28 1998 > DUMP: Tape rewinding > DUMP: 84222 blocks (41.12MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:20:38 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:38:31 1998 > DUMP: Dumping /dev/rsd2b (/sp2) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 109538 blocks (53.49MB) on 0.01 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:20:38 1998 > DUMP: Tape rewinding > DUMP: 109562 blocks (53.50MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:25:28 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 04:48:03 1998 > DUMP: Dumping /dev/rsd3e (/sp3) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 121746 blocks (59.45MB) on 0.01 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:25:28 1998 > DUMP: Tape rewinding > DUMP: 121760 blocks (59.45MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:31:30 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:01:18 1998 > DUMP: Dumping /dev/rsd3f (/usr/spool/mail) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 709654 blocks (346.51MB) on 0.04 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: 42.60% done, finished in 0:06 > DUMP: 84.00% done, finished in 0:01 > DUMP: level 7 dump on Sun Feb 22 02:31:30 1998 > DUMP: Tape rewinding > DUMP: 710144 blocks (346.75MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:45:06 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:17:49 1998 > DUMP: Dumping /dev/rsd1a (/usr/local/etc/httpd) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 12236 blocks (5.97MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:45:06 1998 > DUMP: Tape rewinding > DUMP: 12454 blocks (6.08MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:46:59 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:20:04 1998 > DUMP: Dumping /dev/rsd2a (/usr/local) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 576498 blocks (281.49MB) on 0.03 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: 97.17% done, finished in 0:00 > DUMP: level 7 dump on Sun Feb 22 02:46:59 1998 > DUMP: Tape rewinding > DUMP: 577062 blocks (281.77MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:54:18 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:28:41 1998 > DUMP: Dumping /dev/rsd0a (/) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 4658 blocks (2.27MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:54:18 1998 > DUMP: Tape rewinding > DUMP: 4666 blocks (2.28MB) on 1 volume > DUMP: DUMP IS DONE > DUMP: Date of this level 7 dump: Sun Feb 22 02:54:28 1998 > DUMP: Date of last level 3 dump: Sat Feb 21 05:29:03 1998 > DUMP: Dumping /dev/rsd0g (/usr) to /dev/nrmt0 on host bigfoot > DUMP: mapping (Pass I) [regular files] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: mapping (Pass II) [directories] > DUMP: estimated 4516 blocks (2.21MB) on 0.00 tape(s). > DUMP: dumping (Pass III) [directories] > DUMP: dumping (Pass IV) [regular files] > DUMP: level 7 dump on Sun Feb 22 02:54:28 1998 > DUMP: Tape rewinding > DUMP: 4512 blocks (2.20MB) on 1 volume > DUMP: DUMP IS DONE > End time: Sun Feb 22 02:54:59 PST 1998 > ARCHIVING: gemini > gemini:/ > > **** bru: execution summary **** > > Started: Sun Feb 22 02:57:09 1998 > Completed: Sun Feb 22 02:57:50 1998 > Archive id: 34f004852588 > Messages: 0 warnings, 0 errors > Archive I/O: 6920 blocks (13840Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 18 files (15 regular, 3 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/usr > > **** bru: execution summary **** > > Started: Sun Feb 22 02:57:50 1998 > Completed: Sun Feb 22 02:58:34 1998 > Archive id: 34f004ae2595 > Messages: 0 warnings, 0 errors > Archive I/O: 10 blocks (20Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 1 files (1 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/usr/local > > **** bru: execution summary **** > > Started: Sun Feb 22 02:58:34 1998 > Completed: Sun Feb 22 03:00:45 1998 > Archive id: 34f004da259d > Messages: 0 warnings, 0 errors > Archive I/O: 22980 blocks (45960Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 419 files (419 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/usr/local/apache/sites > > **** bru: execution summary **** > > Started: Sun Feb 22 03:00:45 1998 > Completed: Sun Feb 22 03:14:29 1998 > Archive id: 34f0055d25ba > Messages: 0 warnings, 0 errors > Archive I/O: 48900 blocks (97800Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 814 files (814 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > gemini:/mnt/logs > > **** bru: execution summary **** > > Started: Sun Feb 22 03:14:29 1998 > Completed: Sun Feb 22 03:17:10 1998 > Archive id: 34f00895260f > Messages: 0 warnings, 0 errors > Archive I/O: 20 blocks (40Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 5 files (5 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > ARCHIVING: betty > betty:/usr > > **** bru: execution summary **** > > Started: Sun Feb 22 03:15:42 1998 > Completed: Sun Feb 22 03:16:48 1998 > Archive id: 34f008de0465 > Messages: 0 warnings, 0 errors > Archive I/O: 3980 blocks (7960Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 8 files (8 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > betty:/usr/local/samba > > **** bru: execution summary **** > > Started: Sun Feb 22 03:16:48 1998 > Completed: Sun Feb 22 03:17:46 1998 > Archive id: 34f00920046c > Messages: 0 warnings, 0 errors > Archive I/O: 3630 blocks (7260Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 55 files (55 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > ARCHIVING: bigfoot > bigfoot:/var/log0 > > **** bru: execution summary **** > > Started: Sun Feb 22 03:23:13 1998 > Completed: Sun Feb 22 03:30:26 1998 > Archive id: 34f00aa15d23 > Messages: 0 warnings, 0 errors > Archive I/O: 272880 blocks (545760Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 937 files (937 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 > ARCHIVING: ella.pscs.org > ella:/var > > **** bru: execution summary **** > > Started: Sun Feb 22 03:27:39 1998 > Completed: Sun Feb 22 03:28:46 1998 > Archive id: 34f00bab08e0 > Messages: 0 warnings, 0 errors > Archive I/O: 13830 blocks (27660Kb) written > Archive I/O: 0 blocks (0Kb) read > Files written: 58 files (58 regular, 0 other) > Files read: 0 files (0 regular, 0 other) > Write errors: 0 soft, 0 hard > Read errors: 0 soft, 0 hard > Checksum errors: 0 On Sun, 22 February 1998, at 17:47:07, Vadim B. Mikheev wrote: > X-VM-v5-Data: ([t nil nil nil nil nil nil nil nil] > ["1080" "Sun" "22" "February" "1998" "17:47:07" "+0700" "Vadim B. Mikheev" "vadim@sable.krasnoyarsk.su" nil "32" "Re:[HACKERS] How To free resources used by large object Relations?" nil nil nil "2" nil nil (number " " mark "N VadimB. Mikheev Feb 22 32/1080 " thread-indent "\"Re: [HACKERS] How To free resources used by large object Relations?\"\n")nil nil] > nil) > Return-Path: <owner-pgsql-hackers@hub.org> > Received: from hub.org (hub.org [209.47.148.200]) > by abraxas.scene.com (8.8.8/8.8.5) with ESMTP id CAA16288 > for <brett@work.chicken.org>; Sun, 22 Feb 1998 02:51:20 -0800 > Received: from localhost (majordom@localhost) by hub.org (8.8.8/8.7.5) with SMTP id FAA28144; Sun, 22 Feb 1998 05:45:06-0500 (EST) > Received: by hub.org (TLB v0.10a (1.23 tibbs 1997/01/09 00:29:32)); Sun, 22 Feb 1998 05:44:57 -0500 (EST) > Received: (from majordom@localhost) by hub.org (8.8.8/8.7.5) id FAA28023 for pgsql-hackers-outgoing; Sun, 22 Feb 1998 05:44:49-0500 (EST) > Received: from dune.krasnet.ru (dune.krasnet.ru [193.125.44.86]) by hub.org (8.8.8/8.7.5) with ESMTP id FAA27920 for <pgsql-hackers@postgreSQL.org>;Sun, 22 Feb 1998 05:44:29 -0500 (EST) > Received: from sable.krasnoyarsk.su (dune.krasnet.ru [193.125.44.86]) > by dune.krasnet.ru (8.8.7/8.8.7) with ESMTP id RAA00809; > Sun, 22 Feb 1998 17:47:19 +0700 (KRS) > (envelope-from vadim@sable.krasnoyarsk.su) > Message-ID: <34F0022B.60E59681@sable.krasnoyarsk.su> > Date: Sun, 22 Feb 1998 17:47:07 +0700 > From: "Vadim B. Mikheev" <vadim@sable.krasnoyarsk.su> > Organization: ITTS (Krasnoyarsk) > X-Mailer: Mozilla 4.04 [en] (X11; I; FreeBSD 2.2.5-RELEASE i386) > MIME-Version: 1.0 > To: Maurice Gittens <mgittens@gits.nl> > CC: pgsql-hackers@postgreSQL.org > Subject: Re: [HACKERS] How To free resources used by large object Relations? > References: <018001bd3e01$7651be80$fcf3b2c2@caleb..gits.nl> > Content-Type: text/plain; charset=us-ascii > Content-Transfer-Encoding: 7bit > Sender: owner-pgsql-hackers@hub.org > Precedence: bulk > > Maurice Gittens wrote: > > > > Hi, > > > > I've changed the large object memory managment strategy to ensure that > > each large object has it's own memory context. > > This way I can free all memory for a large object when I lo_close > > is called for it's oid. This seems to work. > > > > I've noticed that the heap_close function used to close the heap used > > by a large object doesn't really do any thing. (It calls RelationClose > > which decrements some reference count). > > > > Somehow I have to free the relation from the cache in the following > > situations: > > 1. In a transaction I must free the stuff when the transaction is > > commited/aborted. > > Backend does it, don't worry. > > > 2. Otherwise it must happen when lo_close is called. > > It seems that you can't remove relation from cache untill > commit/abort, currently: backend uses local cache to unlink > files of relations created in transaction if abort... > We could change relcache.c:RelationPurgeLocalRelation() > to read from pg_class directly... > > But how many LO do you create in single xact ? > Is memory allocated for cache so big ? > > Vadim On Sun, 22 February 1998, at 02:49:37, Eve Arden wrote: > X-VM-v5-Data: ([t nil nil nil nil nil nil nil nil] > ["129" "Sun" "22" "February" "1998" "02:49:37" "-0800" "Eve Arden" "root@eve.speakeasy.org" nil "2" "" nil nil nil"2" nil nil (number " " mark "N Eve Arden Feb 22 2/129 " thread-indent "\"\"\n") nil nil] > nil) > Return-Path: <root@eve.speakeasy.org> > Received: from eve.speakeasy.org (root@eve.speakeasy.org [199.238.226.1]) > by abraxas.scene.com (8.8.8/8.8.5) with ESMTP id CAA16276 > for <brett@work.chicken.org>; Sun, 22 Feb 1998 02:49:50 -0800 > Received: (from root@localhost) by eve.speakeasy.org (8.8.5/8.7.3) id CAA01899; Sun, 22 Feb 1998 02:49:37 -0800 (PST) > Date: Sun, 22 Feb 1998 02:49:37 -0800 (PST) > From: Eve Arden <root@eve.speakeasy.org> > Message-Id: <199802221049.CAA01899@eve.speakeasy.org> > > # Checking accounts from NIS. > >--WARN-- [acc001w] Login ID a-ron is disabled, but still has a valid shell (/usr/local/bin/tcsh).
Vadim wrote:
>
> ??? Old instance rules system was removed by Jolly & Andrew and so
> it never supported SQL. I hope that Jan will give us PL/pgSQL soon
> and it will be used for triggers, without changing current trigger
> implementation...
I'll start on PL/pgSQL as soon as the view-aggregate, insert-
select-view and the pg_user-freed-cc_tupdesc problems are
fixed. But due to time I think PL/pgSQL will be an add on
after 6.3 and I'm very sure it will not require any more
changes to the trigger implementation.
Jan
--
#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me. #
#======================================== jwieck@debis.com (Jan Wieck) #
Re: pl/{perl,pgsql} (was Re: AW: [HACKERS] triggers, views and rules (not instead))
От
jwieck@debis.com (Jan Wieck)
Дата:
Brett wrote:
>
>
> On Sun, 22 February 1998, at 18:26:45, Vadim B. Mikheev wrote:
>
> > ??? Old instance rules system was removed by Jolly & Andrew and so
> > it never supported SQL. I hope that Jan will give us PL/pgSQL soon
> > and it will be used for triggers, without changing current trigger
> > implementation...
>
> Is develemopment being done for PL/pgSQL? What are peoples ideas for
> this? I've never used a commercial db before, and the free ones don't
> usualle have a stored PL language. What sort of things are you guys
> anticipating? In the writing of PL/perl i've been tempted to give
> lots of access to the backend internals from perl (why not, it should
> have all the facilities C function programmers have!) What do you think?
No actual development - just have something in mind how I
would implement it. I'll get into details after 6.3 release.
PL/pgSQL will have at least the following capabilities:
- local variable
- local records
- access to the database over SPI
- control structures (if/else/while/loop)
- elog messages
- triggers can modify new tuple
- triggers can skip operation
Why not handing many backend internals through a PL? Just to
let ordinary users use the language without breaking
security. The implementation of PL/Tcl uses a safe Tcl
interpreter for the evaluation of the Tcl functions/trigger-
procedures. A safe Tcl interpreter has very limited command
set. No access to filesystem, no access to networking, no
loading of other packages so nothing dangerous.
If perl doesn't have such a restricted interpreter facility,
then perl might never become a TRUSTED procedural language
like Tcl is. Remember, if the PL/perl implementation gives
an ordinary user the right just to open a file for writing, a
function independent who created it could damage database
files directly. This MUST be restricted to superusers and
this is the reason why the C language isn't TRUSTED.
>
> Also, as far as argument passing goes: strings & numbers get passed as
> perl scalars, and most other types get passed as a Posgres::Type
> object (with methods for conversion etc). Right now I've got a switch
> block on the type oid and I have many case statements and a few bodies
> for these conversions.
>
> The conversions are hard-coded in the .c file (via the case
> statements). The only reason any particular input type shows up in
> perl any particular way (as a scalar (string/int) or Postgres::Type)
> is because there's a hardcoded case statement for it. Of course, the
> default is a Postgres::Type. Which means new integer types show up as
> a Postgres::Type, which could be considered a bad thing. Right now
> part of what i'm doing is checking the typbyval and then passing that
> type as an integer scalar (excluding selected types that don't make
> sense as ints).. Maybe the default case should be the types ouptut
> function?
Whatever perl scalars are - don't know. Tcl is happy with
string representation of anything on the evaluation level and
Tcl_Eval() leaves a string in the interpreter result. So I
used the registered input/output functions to convert
anything from/into strings to communicate with the
interpreter.
Whatever is given to or returned from a Tcl function in
PL/Tcl will be in the external representation. This is what
the user sees if he selects from a table in psql and what has
to be given on insert/update. So on the PL/Tcl level,
anything is the external representation as defined by the
types registered input/output functions. This is the values
format humans deal with best.
I know that the way I choose isn't the performance optimized
one. But blowing up the functions code by handling binary
data wouldn't be either.
When implementing perl or Tcl as a procedural language, we
must satisfy the need of perl/Tcl programmers. These
programmers must not have any C skill, but they sure will
know how to read/create a string in the external
representation. For some types (especially for user created
types) it might be hard to figure out what each bit in the
binary Datum is for if you aren't familiar with C.
Jan
--
#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me. #
#======================================== jwieck@debis.com (Jan Wieck) #
Re: pl/{perl,pgsql} (was Re: AW: [HACKERS] triggers, views and rules (not instead))
От
jwieck@debis.com (Jan Wieck)
Дата:
Brett wrote:
>
>
> On Sun, 22 February 1998, at 18:26:45, Vadim B. Mikheev wrote:
>
> > ??? Old instance rules system was removed by Jolly & Andrew and so
> > it never supported SQL. I hope that Jan will give us PL/pgSQL soon
> > and it will be used for triggers, without changing current trigger
> > implementation...
>
> Is develemopment being done for PL/pgSQL? What are peoples ideas for
> this? I've never used a commercial db before, and the free ones don't
> usualle have a stored PL language. What sort of things are you guys
> anticipating? In the writing of PL/perl i've been tempted to give
> lots of access to the backend internals from perl (why not, it should
> have all the facilities C function programmers have!) What do you think?
No actual development - just have something in mind how I
would implement it. I'll get into details after 6.3 release.
PL/pgSQL will have at least the following capabilities:
- local variable
- local records
- access to the database over SPI
- control structures (if/else/while/loop)
- elog messages
- triggers can modify new tuple
- triggers can skip operation
Why not handing many backend internals through a PL? Just to
let ordinary users use the language without breaking
security. The implementation of PL/Tcl uses a safe Tcl
interpreter for the evaluation of the Tcl functions/trigger-
procedures. A safe Tcl interpreter has very limited command
set. No access to filesystem, no access to networking, no
loading of other packages so nothing dangerous.
If perl doesn't have such a restricted interpreter facility,
then perl might never become a TRUSTED procedural language
like Tcl is. Remember, if the PL/perl implementation gives
an ordinary user the right just to open a file for writing, a
function independent who created it could damage database
files directly. This MUST be restricted to superusers and
this is the reason why the C language isn't TRUSTED.
>
> Also, as far as argument passing goes: strings & numbers get passed as
> perl scalars, and most other types get passed as a Posgres::Type
> object (with methods for conversion etc). Right now I've got a switch
> block on the type oid and I have many case statements and a few bodies
> for these conversions.
>
> The conversions are hard-coded in the .c file (via the case
> statements). The only reason any particular input type shows up in
> perl any particular way (as a scalar (string/int) or Postgres::Type)
> is because there's a hardcoded case statement for it. Of course, the
> default is a Postgres::Type. Which means new integer types show up as
> a Postgres::Type, which could be considered a bad thing. Right now
> part of what i'm doing is checking the typbyval and then passing that
> type as an integer scalar (excluding selected types that don't make
> sense as ints).. Maybe the default case should be the types ouptut
> function?
Whatever perl scalars are - don't know. Tcl is happy with
string representation of anything on the evaluation level and
Tcl_Eval() leaves a string in the interpreter result. So I
used the registered input/output functions to convert
anything from/into strings to communicate with the
interpreter.
Whatever is given to or returned from a Tcl function in
PL/Tcl will be in the external representation. This is what
the user sees if he selects from a table in psql and what has
to be given on insert/update. So on the PL/Tcl level,
anything is the external representation as defined by the
types registered input/output functions. This is the values
format humans deal with best.
I know that the way I choose isn't the performance optimized
one. But blowing up the functions code by handling binary
data wouldn't be either.
When implementing perl or Tcl as a procedural language, we
must satisfy the need of perl/Tcl programmers. These
programmers must not have any C skill, but they sure will
know how to read/create a string in the external
representation. For some types (especially for user created
types) it might be hard to figure out what each bit in the
binary Datum is for if you aren't familiar with C.
Jan
--
#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me. #
#======================================== jwieck@debis.com (Jan Wieck) #
Re: pl/{perl,pgsql} (was Re: AW: [HACKERS] triggers, views and rules (not instead))
От
Brett McCormick
Дата:
Please don't CC the root users (or the mailing list twice) on this. I've removed them from the headers. Sorry, I don't know how the addresses got in there. > Brett wrote: > > > > > > On Sun, 22 February 1998, at 18:26:45, Vadim B. Mikheev wrote: > > > > Is develemopment being done for PL/pgSQL? What are peoples ideas for > > this? I've never used a commercial db before, and the free ones don't > > usualle have a stored PL language. What sort of things are you guys > > anticipating? In the writing of PL/perl i've been tempted to give > > lots of access to the backend internals from perl (why not, it should > > have all the facilities C function programmers have!) What do you think? >