diff --git a/doc/TODO.detail/java b/doc/TODO.detail/java new file mode 100644 index 0000000000000000000000000000000000000000..ebc5b2a47f104a69a2dd22a3b6e3df009a9b1997 --- /dev/null +++ b/doc/TODO.detail/java @@ -0,0 +1,407 @@ +From pgsql-hackers-owner+M4145@postgresql.org Sat Feb 3 05:54:06 2001 +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id FAA22302 + for <pgman@candle.pha.pa.us>; Sat, 3 Feb 2001 05:54:04 -0500 (EST) +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by mail.postgresql.org (8.11.1/8.11.1) with SMTP id f13Ap4q95132; + Sat, 3 Feb 2001 05:51:04 -0500 (EST) + (envelope-from pgsql-hackers-owner+M4145@postgresql.org) +Received: from mail.retep.org.uk ([216.126.85.184]) + by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f13AnIq94863 + for <pgsql-hackers@postgresql.org>; Sat, 3 Feb 2001 05:49:18 -0500 (EST) + (envelope-from peter@retep.org.uk) +Received: from heather.retep.org.uk ([193.113.118.193]) + (authenticated) + by mail.retep.org.uk (8.11.1/8.11.1) with ESMTP id f13AlnO94823; + Sat, 3 Feb 2001 05:47:49 -0500 (EST) + (envelope-from peter@retep.org.uk) +Message-Id: <5.0.2.1.0.20010203103036.009efec0@mail.retep.org.uk> +X-Sender: peter@mail.retep.org.uk +X-Mailer: QUALCOMM Windows Eudora Version 5.0.2 +Date: Sat, 03 Feb 2001 10:46:24 +0000 +To: Alex Pilosov <alex@pilosoft.com>, tomasz konefal <twkonefal@yahoo.ca> +From: Peter Mount <peter@retep.org.uk> +Subject: Re: [HACKERS] TODO list: Allow Java server-side programming +Cc: pgsql-hackers@postgresql.org +In-Reply-To: <Pine.BSO.4.10.10102021453160.9372-100000@spider.pilosoft.c + om> +References: <20010202194049.38902.qmail@web12003.mail.yahoo.com> +Mime-Version: 1.0 +Content-Type: text/plain; charset="us-ascii"; format=flowed +Precedence: bulk +Sender: pgsql-hackers-owner@postgresql.org +Status: OR + +At 14:57 02/02/01 -0500, Alex Pilosov wrote: +>On Fri, 2 Feb 2001, tomasz konefal wrote: +> +> > could someone please clarify what "Allow Java +> > server-side programming" actually means? what are the +> > limitations of using java and jdbc with pgsql? +> +>It means to embed Java interpreter inside postgres, and allow writing +>stored procedures and triggers in Java. + +Thats correct. Basically you are talking of something like PL/Java. The +Java side would be simple, but its linking the JVM to the backend that's +the problem. + +It's been a while since I delved into the backend, but unless it's changed +from fork() to threading, I don't really see this happening, unless someone +who knows C that well knows of a portable way of communicating between two +processes - other than RMI. If that could be solved, then you could use JNI +to interface the JVM. + +I know some people think this would slow the backend down, but it's only +the instanciation of the JVM thats slow, hence the other reason fork() is +holding this back. Ideally you would want the JVM to be running with +PostMaster, and then each backend can then use the JVM as and when necessary. + +Obviously you wouldn't want a JVM in every installation, but there are a +lot of good reasons to have this capability. For example, as part of the +course I did this week, we used Tomcat (Servlet/JSP/Web server). Now +there's no reason why Tomcat could run within the same JVM. JBoss is +another good example (EJB Server). The JBoss team have actually got Tomcat +to run within the same JVM. Doesn't hinder performance at all, but does +reduce the memory footprint. + +This is a good future thing to look into (why not for 8.0 ;-) ). If we +could find an _optional_ way of hooking the backend direct into the JVM, we +could get PostgreSQL into a lot of new areas. It also would make things +like CORBA etc a doddle. + +PS: I'm writing down notes of the course to go onto the JDBC web site this +weekend, so there's some nice things for EJB, RMI, Corba etc. + +More later, Peter + + +From pgsql-hackers-owner+M4153@postgresql.org Sat Feb 3 11:54:12 2001 +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id LAA13446 + for <pgman@candle.pha.pa.us>; Sat, 3 Feb 2001 11:54:12 -0500 (EST) +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by mail.postgresql.org (8.11.1/8.11.1) with SMTP id f13GrZq17345; + Sat, 3 Feb 2001 11:53:35 -0500 (EST) + (envelope-from pgsql-hackers-owner+M4153@postgresql.org) +Received: from mailout04.sul.t-online.com (mailout04.sul.t-online.com [194.25.134.18]) + by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f13GnZq17000 + for <pgsql-hackers@postgresql.org>; Sat, 3 Feb 2001 11:49:37 -0500 (EST) + (envelope-from peter_e@gmx.net) +Received: from fwd06.sul.t-online.com + by mailout04.sul.t-online.com with smtp + id 14P5rE-0000zq-00; Sat, 03 Feb 2001 17:48:16 +0100 +Received: from peter.localdomain (520083510237-0001@[212.185.245.12]) by fmrl06.sul.t-online.com + with esmtp id 14P5r6-0YvD60C; Sat, 3 Feb 2001 17:48:08 +0100 +Date: Sat, 3 Feb 2001 17:56:33 +0100 (CET) +From: Peter Eisentraut <peter_e@gmx.net> +To: Peter Mount <peter@retep.org.uk> +cc: Alex Pilosov <alex@pilosoft.com>, tomasz konefal <twkonefal@yahoo.ca>, + <pgsql-hackers@postgresql.org> +Subject: Re: [HACKERS] TODO list: Allow Java server-side programming +In-Reply-To: <5.0.2.1.0.20010203103036.009efec0@mail.retep.org.uk> +Message-ID: <Pine.LNX.4.30.0102031746220.8648-100000@peter.localdomain> +MIME-Version: 1.0 +Content-Type: TEXT/PLAIN; charset=US-ASCII +X-Sender: 520083510237-0001@t-dialin.net +Precedence: bulk +Sender: pgsql-hackers-owner@postgresql.org +Status: OR + +Peter Mount writes: + +> Thats correct. Basically you are talking of something like PL/Java. The +> Java side would be simple, but its linking the JVM to the backend that's +> the problem. + +I've tried that recently, here's how it looks as far as Linux JVMs go: + +* Kaffe has a very polluted name space. Calls to its own functions get +resolved to PostgreSQL, and vice versa. Crash and burn result. The Kaffe +folks have admitted that this should be fixed but I didn't look farther +yet. + +* The Sun/Blackdown JVM didn't work at all (not even 'java -version') +until I upgraded my libc. Then a simple test run crashes with an "error +external to JVM"; at first it looked like a segfault when referencing a +string constant. In gdb I saw myself faced with about 10 threads running +when nothing was going on yet, at which point I was too exhausted to +proceed. + +* IBM's offering didn't work at all. I don't recall the problem anymore +but I think it didn't even link correctly. + +So currently I don't see how this could become a mainstream project, let +alone across platforms. + +> I know some people think this would slow the backend down, but it's only +> the instanciation of the JVM thats slow, hence the other reason fork() is +> holding this back. Ideally you would want the JVM to be running with +> PostMaster, and then each backend can then use the JVM as and when necessary. + +But how do the other languages cope? Starting up a new Perl for each +backend can't be so cheap either. + +-- +Peter Eisentraut peter_e@gmx.net http://yi.org/peter-e/ + + +From pgsql-hackers-owner+M4154@postgresql.org Sat Feb 3 12:37:02 2001 +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id MAA00813 + for <pgman@candle.pha.pa.us>; Sat, 3 Feb 2001 12:37:01 -0500 (EST) +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by mail.postgresql.org (8.11.1/8.11.1) with SMTP id f13Haiq21225; + Sat, 3 Feb 2001 12:36:44 -0500 (EST) + (envelope-from pgsql-hackers-owner+M4154@postgresql.org) +Received: from spider.pilosoft.com (p55-222.acedsl.com [160.79.55.222]) + by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f13HX9q20913 + for <pgsql-hackers@postgresql.org>; Sat, 3 Feb 2001 12:33:09 -0500 (EST) + (envelope-from alex@pilosoft.com) +Received: from localhost (alexmail@localhost) + by spider.pilosoft.com (8.9.3/8.9.3) with ESMTP id MAA09231; + Sat, 3 Feb 2001 12:36:01 -0500 (EST) +Date: Sat, 3 Feb 2001 12:36:01 -0500 (EST) +From: Alex Pilosov <alex@pilosoft.com> +To: Peter Mount <peter@retep.org.uk> +cc: Alex Pilosov <alex@pilosoft.com>, tomasz konefal <twkonefal@yahoo.ca>, + pgsql-hackers@postgresql.org +Subject: Re: [HACKERS] TODO list: Allow Java server-side programming +In-Reply-To: <5.0.2.1.0.20010203103036.009efec0@mail.retep.org.uk> +Message-ID: <Pine.BSO.4.10.10102031220470.10437-100000@spider.pilosoft.com> +MIME-Version: 1.0 +Content-Type: TEXT/PLAIN; charset=US-ASCII +Precedence: bulk +Sender: pgsql-hackers-owner@postgresql.org +Status: OR + +On Sat, 3 Feb 2001, Peter Mount wrote: + +> It's been a while since I delved into the backend, but unless it's +> changed from fork() to threading, I don't really see this happening, +> unless someone who knows C that well knows of a portable way of +> communicating between two processes - other than RMI. If that could be +> solved, then you could use JNI to interface the JVM. +There are many ways one can do this: +a) each backend will have a JVM linked in (shared object). This is the +way perl/tcl/ruby is embedded, and it works pretty nice. But, Java +['s memory requirement] sucks, therefore, this may not be the optimal +way. + +> I know some people think this would slow the backend down, but it's +> only the instanciation of the JVM thats slow, hence the other reason +> fork() is holding this back. Ideally you would want the JVM to be +> running with PostMaster, and then each backend can then use the JVM as +> and when necessary. +b) since JVM is threaded, it may be more efficient to have a dedicated +process running JVM, and accepting some sort of IPC connections from +postgres processes. The biggest problem here is SPI, there aren't a good +way for that JVM to talk back to database. + +c) temporarily, to have quick working code, you can reach java using hacks +using programming languages already built into postgres. Both TCL (tcl +blend) and Perl (JPL and another hack which name escapes me) are able to +execute java code. SPI is possible, I think both of these bindings are +two-way (you can go perl-java-perl-java). Might be worth a quick try? +-alex + + + +From pgsql-hackers-owner+M4164@postgresql.org Sun Feb 4 04:23:42 2001 +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id EAA04260 + for <pgman@candle.pha.pa.us>; Sun, 4 Feb 2001 04:23:41 -0500 (EST) +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by mail.postgresql.org (8.11.1/8.11.1) with SMTP id f149Nhx75443; + Sun, 4 Feb 2001 04:23:43 -0500 (EST) + (envelope-from pgsql-hackers-owner+M4164@postgresql.org) +Received: from me.tm.ee (adsl895.estpak.ee [213.168.23.133]) + by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f149Mgx75338 + for <pgsql-hackers@postgresql.org>; Sun, 4 Feb 2001 04:22:42 -0500 (EST) + (envelope-from hannu@tm.ee) +Received: from tm.ee (IDENT:hannu@localhost.localdomain [127.0.0.1]) + by me.tm.ee (8.9.3/8.9.3) with ESMTP id LAA01488; + Sun, 4 Feb 2001 11:18:09 +0200 +Message-ID: <3A7D1E51.E383AB7F@tm.ee> +Date: Sun, 04 Feb 2001 11:18:09 +0200 +From: Hannu Krosing <hannu@tm.ee> +X-Mailer: Mozilla 4.72 [en] (X11; U; Linux 2.2.17 i686) +X-Accept-Language: en +MIME-Version: 1.0 +To: Peter Mount <peter@retep.org.uk> +CC: Alex Pilosov <alex@pilosoft.com>, tomasz konefal <twkonefal@yahoo.ca>, + pgsql-hackers@postgresql.org +Subject: Re: [HACKERS] TODO list: Allow Java server-side programming +References: <20010202194049.38902.qmail@web12003.mail.yahoo.com> <5.0.2.1.0.20010203103036.009efec0@mail.retep.org.uk> +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 7bit +Precedence: bulk +Sender: pgsql-hackers-owner@postgresql.org +Status: OR + +Peter Mount wrote: +> +> At 14:57 02/02/01 -0500, Alex Pilosov wrote: +> >On Fri, 2 Feb 2001, tomasz konefal wrote: +> > +> > > could someone please clarify what "Allow Java +> > > server-side programming" actually means? what are the +> > > limitations of using java and jdbc with pgsql? +> > +> >It means to embed Java interpreter inside postgres, and allow writing +> >stored procedures and triggers in Java. +> +> Thats correct. Basically you are talking of something like PL/Java. The +> Java side would be simple, but its linking the JVM to the backend that's +> the problem. +> +> It's been a while since I delved into the backend, but unless it's changed +> from fork() to threading, + +Someone posted here recently his port/tweaks of backend so that it used +threads instead of fork(). IIRC it was done to be used inside a java +client in an embedded system. + +---------------- +Hannu + +From pgsql-hackers-owner+M4168@postgresql.org Sun Feb 4 06:54:27 2001 +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id GAA19741 + for <pgman@candle.pha.pa.us>; Sun, 4 Feb 2001 06:54:26 -0500 (EST) +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by mail.postgresql.org (8.11.1/8.11.1) with SMTP id f14BsOx83329; + Sun, 4 Feb 2001 06:54:24 -0500 (EST) + (envelope-from pgsql-hackers-owner+M4168@postgresql.org) +Received: from mail.retep.org.uk ([216.126.85.184]) + by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f14Bs9x83240 + for <pgsql-hackers@postgresql.org>; Sun, 4 Feb 2001 06:54:09 -0500 (EST) + (envelope-from peter@retep.org.uk) +Received: from heather.retep.org.uk ([193.113.241.180]) + (authenticated) + by mail.retep.org.uk (8.11.1/8.11.1) with ESMTP id f14BqkR83161; + Sun, 4 Feb 2001 06:52:46 -0500 (EST) + (envelope-from peter@retep.org.uk) +Message-Id: <5.0.2.1.0.20010204114942.00a0c8d0@mail.retep.org.uk> +X-Sender: peter@mail.retep.org.uk +X-Mailer: QUALCOMM Windows Eudora Version 5.0.2 +Date: Sun, 04 Feb 2001 11:51:21 +0000 +To: Peter Eisentraut <peter_e@gmx.net> +From: Peter Mount <peter@retep.org.uk> +Subject: Re: [HACKERS] TODO list: Allow Java server-side programming +Cc: Alex Pilosov <alex@pilosoft.com>, tomasz konefal <twkonefal@yahoo.ca>, + <pgsql-hackers@postgresql.org> +In-Reply-To: <Pine.LNX.4.30.0102031746220.8648-100000@peter.localdomain> +References: <5.0.2.1.0.20010203103036.009efec0@mail.retep.org.uk> +Mime-Version: 1.0 +Content-Type: text/plain; charset="us-ascii"; format=flowed +Precedence: bulk +Sender: pgsql-hackers-owner@postgresql.org +Status: OR + +At 17:56 03/02/01 +0100, Peter Eisentraut wrote: +>Peter Mount writes: +> +> > Thats correct. Basically you are talking of something like PL/Java. The +> > Java side would be simple, but its linking the JVM to the backend that's +> > the problem. +> +>I've tried that recently, here's how it looks as far as Linux JVMs go: + +[snip] + + +>So currently I don't see how this could become a mainstream project, let +>alone across platforms. + +I don't think it would be, but it would be a good side-project. Over time +the various JVM's should become better to interface with. + + +> > I know some people think this would slow the backend down, but it's only +> > the instanciation of the JVM thats slow, hence the other reason fork() is +> > holding this back. Ideally you would want the JVM to be running with +> > PostMaster, and then each backend can then use the JVM as and when +> necessary. +> +>But how do the other languages cope? Starting up a new Perl for each +>backend can't be so cheap either. + +But a lot cheaper than Java. + +Peter + + +From pgsql-hackers-owner+M4169@postgresql.org Sun Feb 4 06:57:24 2001 +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by candle.pha.pa.us (8.9.0/8.9.0) with ESMTP id GAA19817 + for <pgman@candle.pha.pa.us>; Sun, 4 Feb 2001 06:57:23 -0500 (EST) +Received: from mail.postgresql.org (webmail.postgresql.org [216.126.85.28]) + by mail.postgresql.org (8.11.1/8.11.1) with SMTP id f14BvLx83711; + Sun, 4 Feb 2001 06:57:21 -0500 (EST) + (envelope-from pgsql-hackers-owner+M4169@postgresql.org) +Received: from mail.retep.org.uk ([216.126.85.184]) + by mail.postgresql.org (8.11.1/8.11.1) with ESMTP id f14Bv7x83611 + for <pgsql-hackers@postgresql.org>; Sun, 4 Feb 2001 06:57:07 -0500 (EST) + (envelope-from peter@retep.org.uk) +Received: from heather.retep.org.uk ([193.113.241.180]) + (authenticated) + by mail.retep.org.uk (8.11.1/8.11.1) with ESMTP id f14BtjR83557; + Sun, 4 Feb 2001 06:55:45 -0500 (EST) + (envelope-from peter@retep.org.uk) +Message-Id: <5.0.2.1.0.20010204115139.009f1c50@mail.retep.org.uk> +X-Sender: peter@mail.retep.org.uk +X-Mailer: QUALCOMM Windows Eudora Version 5.0.2 +Date: Sun, 04 Feb 2001 11:54:20 +0000 +To: Alex Pilosov <alex@pilosoft.com> +From: Peter Mount <peter@retep.org.uk> +Subject: Re: [HACKERS] TODO list: Allow Java server-side programming +Cc: Alex Pilosov <alex@pilosoft.com>, tomasz konefal <twkonefal@yahoo.ca>, + pgsql-hackers@postgresql.org +In-Reply-To: <Pine.BSO.4.10.10102031220470.10437-100000@spider.pilosoft. + com> +References: <5.0.2.1.0.20010203103036.009efec0@mail.retep.org.uk> +Mime-Version: 1.0 +Content-Type: text/plain; charset="us-ascii"; format=flowed +Precedence: bulk +Sender: pgsql-hackers-owner@postgresql.org +Status: OR + +At 12:36 03/02/01 -0500, Alex Pilosov wrote: +>On Sat, 3 Feb 2001, Peter Mount wrote: + +[snip] + + +> > I know some people think this would slow the backend down, but it's +> > only the instanciation of the JVM thats slow, hence the other reason +> > fork() is holding this back. Ideally you would want the JVM to be +> > running with PostMaster, and then each backend can then use the JVM as +> > and when necessary. +>b) since JVM is threaded, it may be more efficient to have a dedicated +>process running JVM, and accepting some sort of IPC connections from +>postgres processes. The biggest problem here is SPI, there aren't a good +>way for that JVM to talk back to database. + +That was my other idea, but it is the IPC thats problematical. You would +still need to do some native api to implement some messaging system between +the two. + +However, at the other extreme there is RPC, which is possible now, but +would be a lot slower. + + +>c) temporarily, to have quick working code, you can reach java using hacks +>using programming languages already built into postgres. Both TCL (tcl +>blend) and Perl (JPL and another hack which name escapes me) are able to +>execute java code. SPI is possible, I think both of these bindings are +>two-way (you can go perl-java-perl-java). Might be worth a quick try? + +Might be one way to go... + +Peter + +>-alex +> + +