Re: [HACKERS] Block level concurrency during recovery

2008-10-23 Thread Heikki Linnakangas
Simon Riggs wrote: I'm undecided as to whether this is too much code or too little. I'm somewhat uncertain as to the locking requirements for the physical scan during a vacuum. I've worked out various options if we need to change this. For the B-tree, an exclusive lock is enough to modify the

Re: [HACKERS] Making pg_standby compression-friendly

2008-10-23 Thread Heikki Linnakangas
Charles Duffy wrote: I'm interested in compressing archived WAL segments in an environment set up for PITR in the interests of reducing both network traffic and storage requirements. However, pg_standby presently checks file sizes, requiring that an archive segment be exactly the right size to

Re: [HACKERS] PGDay.it collation discussion notes

2008-10-23 Thread Heikki Linnakangas
Dave Gudeman wrote: On Mon, Oct 20, 2008 at 2:28 AM, Heikki Linnakangas [EMAIL PROTECTED] wrote: Tom Lane wrote: Another objection to this design is that it's completely unclear that functions from text to text should necessarily yield the same collation that went into them, but if you treat

Re: [HACKERS] Making pg_standby compression-friendly

2008-10-23 Thread Charles Duffy
On Thu, Oct 23, 2008 at 1:15 AM, Heikki Linnakangas [EMAIL PROTECTED] wrote: Charles Duffy wrote: I'm interested in compressing archived WAL segments in an environment set up for PITR in the interests of reducing both network traffic and storage requirements. However, pg_standby presently

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Greg Stark
For making psql fully scriptable I would think it would be smarter to embed a full well-supported existing language rather than trying to invent a new one. If we do want to to that I would suggest looking at lua which is intended to be used this way. greg On 23 Oct 2008, at 05:45 AM,

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Magnus Hagander
On 23 okt 2008, at 00.48, Alvaro Herrera [EMAIL PROTECTED] wrote: Josh Berkus wrote: Hackers, Just had a feature request from Wheeler, and I don't see why it shouldn't go on our todo list. I think you're asking for more scriptability in psql. Personally I think that would be a great

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Pavel Stehule
2008/10/23 Greg Stark [EMAIL PROTECTED]: For making psql fully scriptable I would think it would be smarter to embed a full well-supported existing language rather than trying to invent a new one. plpgsql? regards Pavel If we do want to to that I would suggest looking at lua which is

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Peter Eisentraut
Pavel Stehule wrote: 2008/10/23 Greg Stark [EMAIL PROTECTED]: For making psql fully scriptable I would think it would be smarter to embed a full well-supported existing language rather than trying to invent a new one. plpgsql? I think plpgsql is a pretty good example of the sort of disaster

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Peter Eisentraut
Magnus Hagander wrote: If you want full scripting, look at pgscript, one of this summers gsoc projects. It'll ship in the next pgadmin and is also available as a standalone executable. Yet another language? What people asking for psql scriptability really want, in my estimate, is the

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Pavel Stehule
2008/10/23 Peter Eisentraut [EMAIL PROTECTED]: Magnus Hagander wrote: If you want full scripting, look at pgscript, one of this summers gsoc projects. It'll ship in the next pgadmin and is also available as a standalone executable. Yet another language? it is more crazy - pgscript is based

Re: [HACKERS] Deriving Recovery Snapshots

2008-10-23 Thread Simon Riggs
On Thu, 2008-10-23 at 08:40 +0300, Heikki Linnakangas wrote: Simon Riggs wrote: On Wed, 2008-10-22 at 21:47 +0100, Simon Riggs wrote: But once you reach 64 transactions, you'll need to write an extra WAL record for every subtransaction, which currently I've managed to avoid. Yes,

[HACKERS] Unicode escapes in literals

2008-10-23 Thread Peter Eisentraut
I would like to add an escape mechanism to PostgreSQL for entering arbitrary Unicode characters into string literals. We currently only have the option of entering the character directly via the keyboard or cut-and-paste, which is difficult for a number of reasons, such as when the font

Re: [HACKERS] Block level concurrency during recovery

2008-10-23 Thread Simon Riggs
On Thu, 2008-10-23 at 09:09 +0300, Heikki Linnakangas wrote: However, we require that in b-tree vacuum, you take a cleanup lock on *every* leaf page of the index, not only those that you modify. That's a problem, because there's no trace of such pages in the WAL. OK, good. Thanks for the

Re: [HACKERS] Deriving Recovery Snapshots

2008-10-23 Thread Heikki Linnakangas
Simon Riggs wrote: The patch isn't ready to apply standalone because we need to include the changes to XidInMVCCSnapshot() also, which would take a little while to extract. Let me know if that is worth producing a standalone patch for. FWIW, this patch becomes a lot simpler if you don't change

[HACKERS] EXPLAIN CREATE TABLE AS

2008-10-23 Thread Peter Eisentraut
It turns out you cannot EXPLAIN on CREATE TABLE AS, but it seems to work fine if I extend the grammar as below: ExplainableStmt: SelectStmt | InsertStmt | UpdateStmt | DeleteStmt | DeclareCursorStmt + | CreateAsStmt | ExecuteStmt

Re: [HACKERS] Deriving Recovery Snapshots

2008-10-23 Thread Simon Riggs
On Thu, 2008-10-23 at 13:40 +0300, Heikki Linnakangas wrote: Simon Riggs wrote: The patch isn't ready to apply standalone because we need to include the changes to XidInMVCCSnapshot() also, which would take a little while to extract. Let me know if that is worth producing a standalone

Re: [HACKERS] EXPLAIN CREATE TABLE AS

2008-10-23 Thread Simon Riggs
On Thu, 2008-10-23 at 14:29 +0300, Peter Eisentraut wrote: It turns out you cannot EXPLAIN on CREATE TABLE AS, but it seems to work fine if I extend the grammar as below: Yes please. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via

Re: [HACKERS] Fwd: [PATCHES] Auto Partitioning Patch - WIP version 1

2008-10-23 Thread Nikhil Sontakke
Hi, On Wed, Oct 22, 2008 at 8:14 PM, Jaime Casanova [EMAIL PROTECTED] wrote: just remembering that -patches is a dead list, so i'm sending this to -hackers where it will have more visibility... -- Forwarded message -- On 10/22/08, Nikhil Sontakke [EMAIL PROTECTED] wrote:

Re: [HACKERS] EXPLAIN CREATE TABLE AS

2008-10-23 Thread Tom Lane
Peter Eisentraut [EMAIL PROTECTED] writes: It turns out you cannot EXPLAIN on CREATE TABLE AS, but it seems to work fine if I extend the grammar as below: This seems to me to be something that will look like a wart, not a feature, from the user's point of view. You can't explain CREATE TABLE,

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Andrew Sullivan
On Wed, Oct 22, 2008 at 04:14:11PM -0700, Joshua Drake wrote: True enough, but a car doesn't roll without at least four wheels. I'm not sure I agree: http://en.wikipedia.org/wiki/Image:1885Benz.jpg (Sorry, I couldn't resist.) -- Andrew Sullivan [EMAIL PROTECTED] +1 503 667 4564 x104

Re: [HACKERS] pg_hba options parsing

2008-10-23 Thread Magnus Hagander
Magnus Hagander wrote: This patch changes the options field of pg_hba.conf to take name/value pairs instead of a fixed string. This makes it a lot nicer to deal with auth methods that need more than one parameter, such as LDAP. While at it, it also adds map support to kerberos, gssapi and

Re: [HACKERS] EXPLAIN CREATE TABLE AS

2008-10-23 Thread Dimitri Fontaine
Le jeudi 23 octobre 2008, Tom Lane a écrit : Peter Eisentraut [EMAIL PROTECTED] writes: It turns out you cannot EXPLAIN on CREATE TABLE AS, but it seems to work fine if I extend the grammar as below: This seems to me to be something that will look like a wart, not a feature, from the

Re: [HACKERS] EXPLAIN CREATE TABLE AS

2008-10-23 Thread Peter Eisentraut
Tom Lane wrote: Peter Eisentraut [EMAIL PROTECTED] writes: It turns out you cannot EXPLAIN on CREATE TABLE AS, but it seems to work fine if I extend the grammar as below: This seems to me to be something that will look like a wart, not a feature, from the user's point of view. You can't

Re: [HACKERS] Unicode escapes in literals

2008-10-23 Thread Tom Lane
Peter Eisentraut [EMAIL PROTECTED] writes: SQL has the following escape syntax for it: U'special character: \' [ UESCAPE '\' ] Man that's ugly. Why the ampersand? How do you propose to distinguish this from a perfectly legitimate use of the operator? 2. Convert this syntax to a

Re: [HACKERS] EXPLAIN CREATE TABLE AS

2008-10-23 Thread Tom Lane
Peter Eisentraut [EMAIL PROTECTED] writes: Isn't the whole point of EXPLAIN to expose implementation artifacts in the first place? Touche ... I withdraw the complaint. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make

[HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Zdenek Kotala
Currently in heaptuple.c we have duplicated code. heap_deformtuple and heap_formtuple are mark as a obsolete interface. Is any reason to have still them? I know that they are still used on many places, but is there any stopper to keep these function alive? Zdenek -- Zdenek

[HACKERS] A small performance bug in BTree Infrastructure

2008-10-23 Thread Gokulakannan Somasundaram
Hi All, BTree Insert requires a data-structure called BTStack to report the page splits that have happened in the leaf pages to non-leaf pages upwards. It basically goes back and updates those non-leaf pages. But this will never happen in a search operation. You never need to climb upwards

Re: [HACKERS] Unicode escapes in literals

2008-10-23 Thread Peter Eisentraut
Tom Lane wrote: Peter Eisentraut [EMAIL PROTECTED] writes: SQL has the following escape syntax for it: U'special character: \' [ UESCAPE '\' ] Man that's ugly. Why the ampersand? Yeah, excellent question. It seems completely unnecessary, but it is surely there in the syntax

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Tom Lane
Zdenek Kotala [EMAIL PROTECTED] writes: Currently in heaptuple.c we have duplicated code. heap_deformtuple and heap_formtuple are mark as a obsolete interface. Is any reason to have still them? I know that they are still used on many places, but is there any stopper to keep these

Re: [HACKERS] Unicode escapes in literals

2008-10-23 Thread Tom Lane
Peter Eisentraut [EMAIL PROTECTED] writes: There are some other disadvantages for making a function call. You couldn't use that kind of literal in any other place where the parser calls for a string constant: role names, tablespace locations, passwords, copy delimiters, enum values,

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Zdenek Kotala
Tom Lane napsal(a): Zdenek Kotala [EMAIL PROTECTED] writes: Currently in heaptuple.c we have duplicated code. heap_deformtuple and heap_formtuple are mark as a obsolete interface. Is any reason to have still them? I know that they are still used on many places, but is there any stopper to

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Tom Lane
Zdenek Kotala [EMAIL PROTECTED] writes: Tom Lane napsal(a): Well, aside from the gruntwork needed to convert all the core code that still uses the old APIs, there's the prospect of breaking extension modules that still use the old APIs. It's kind of annoying to have two copies of that code,

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Alvaro Herrera
Zdenek Kotala wrote: Tom Lane napsal(a): Well, aside from the gruntwork needed to convert all the core code that still uses the old APIs, there's the prospect of breaking extension modules that still use the old APIs. It's kind of annoying to have two copies of that code, but less annoying

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Zdenek Kotala
Alvaro Herrera napsal(a): Zdenek Kotala wrote: Tom Lane napsal(a): Well, aside from the gruntwork needed to convert all the core code that still uses the old APIs, there's the prospect of breaking extension modules that still use the old APIs. It's kind of annoying to have two copies of

[HACKERS] patch: Client certificate requirements

2008-10-23 Thread Magnus Hagander
This patch adds a configuration option to pg_hba.conf for clientcert. This makes it possible to have different client certificate requirements on different connections. It also makes sure that if you specify that you want client cert verification and the root store isn't there, we give an error

Re: [HACKERS] Making pg_standby compression-friendly

2008-10-23 Thread Koichi Suzuki
In terms of compress/decompress WAL in archive/restore, please take a look at my project pglesslog, http://pgfoundry.org/projects/pglesslog/ This project compresses WAL segment by replacing full page writes with corresponding incremental logs. When restored, it inserts dummy WAL record to

Re: [HACKERS] Making pg_standby compression-friendly

2008-10-23 Thread Heikki Linnakangas
Koichi Suzuki wrote: In terms of compress/decompress WAL in archive/restore, please take a look at my project pglesslog, http://pgfoundry.org/projects/pglesslog/ This project compresses WAL segment by replacing full page writes with corresponding incremental logs. When restored, it inserts

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Alvaro Herrera
Zdenek Kotala wrote: Alvaro Herrera napsal(a): Agreed, I started doing that some time ago ... it doesn't seem all that complicated. Do you have any half patch? Couldn't find it here, sorry :-( -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL

Re: [HACKERS] patch: Client certificate requirements

2008-10-23 Thread Magnus Hagander
Magnus Hagander wrote: This patch adds a configuration option to pg_hba.conf for clientcert. This makes it possible to have different client certificate requirements on different connections. It also makes sure that if you specify that you want client cert verification and the root store isn't

Re: [HACKERS] double-buffering page writes

2008-10-23 Thread Alvaro Herrera
ITAGAKI Takahiro wrote: I have some comments about the double-buffering: Since posting this patch I have realized that this implementation is bogus. I'm now playing with WAL-logging hint bits though. As to your questions: - Are there any performance degradation because of addtional memcpy?

Re: [HACKERS] SSL cleanups/hostname verification

2008-10-23 Thread Magnus Hagander
Tom Lane wrote: Magnus Hagander [EMAIL PROTECTED] writes: The patch seems pretty far short of sufficient as far as supporting a new conninfo option goes --- for instance it appears to leak the string at disconnect. Check through all the references to some existing option field to see if you

Re: [HACKERS] Block level concurrency during recovery

2008-10-23 Thread Heikki Linnakangas
Simon Riggs wrote: It would also be possible to introduce a special tweak there which is that if the block is not in cache, don't read it in at all. If its not in cache we know that nobody has a pin on it, so don't need to read it in just to say got the lock. That icing for later. Heh, that's

Re: [HACKERS] Unicode escapes in literals

2008-10-23 Thread Andrew Sullivan
On Thu, Oct 23, 2008 at 06:04:43PM +0300, Peter Eisentraut wrote: Man that's ugly. Why the ampersand? Yeah, excellent question. It seems completely unnecessary, but it is surely there in the syntax diagram. Probably because many Unicode representations are done with U+ followed by 4-6

Re: [HACKERS] double-buffering page writes

2008-10-23 Thread Heikki Linnakangas
Alvaro Herrera wrote: ITAGAKI Takahiro wrote: I have some comments about the double-buffering: Since posting this patch I have realized that this implementation is bogus. I'm now playing with WAL-logging hint bits though. Yeah, the torn page + hint bit updates problem is the tough

Re: [HACKERS] SSL cleanups/hostname verification

2008-10-23 Thread Tom Lane
Magnus Hagander [EMAIL PROTECTED] writes: Looking over it again, that's pretty much the only one I find. I checked against sslmode. Did you spot something else? No, I just thought that it looked like too small a patch for adding a new conn option, and complained as soon as I found something

Re: [HACKERS] Unicode escapes in literals

2008-10-23 Thread Tom Lane
Andrew Sullivan [EMAIL PROTECTED] writes: On Thu, Oct 23, 2008 at 06:04:43PM +0300, Peter Eisentraut wrote: Yeah, excellent question. It seems completely unnecessary, but it is surely there in the syntax diagram. Probably because many Unicode representations are done with U+ followed by

Re: [HACKERS] Block level concurrency during recovery

2008-10-23 Thread Simon Riggs
On Thu, 2008-10-23 at 19:21 +0300, Heikki Linnakangas wrote: Simon Riggs wrote: It would also be possible to introduce a special tweak there which is that if the block is not in cache, don't read it in at all. If its not in cache we know that nobody has a pin on it, so don't need to read

Re: [HACKERS] double-buffering page writes

2008-10-23 Thread Tom Lane
Heikki Linnakangas [EMAIL PROTECTED] writes: Alvaro Herrera wrote: I thought about that too. I admit I am not sure if this really works portably; however I don't want to add a palloc() to that routine. It should work, AFAIK, but unaligned memcpy()s and write()s can be a significantly

Re: [HACKERS] Block level concurrency during recovery

2008-10-23 Thread Heikki Linnakangas
Simon Riggs wrote: On Thu, 2008-10-23 at 19:21 +0300, Heikki Linnakangas wrote: You have other issues with those still, namely that table locks are not yet taken appropriately, so I'm not sure if this is worth worrying about until that's done. Please explain. If you know of a correctness

Re: [HACKERS] psql Feature request \set query

2008-10-23 Thread Josh Berkus
Everyone, What people asking for psql scriptability really want, in my estimate, is the ability to write SQL plus some control structures anywhere, in the server, in the client, or so that they don't have to know where. Commercial vendors have that: Oracle has PL/SQL as server-side language

Re: [HACKERS] Block level concurrency during recovery

2008-10-23 Thread Simon Riggs
On Thu, 2008-10-23 at 20:24 +0300, Heikki Linnakangas wrote: Simon Riggs wrote: On Thu, 2008-10-23 at 19:21 +0300, Heikki Linnakangas wrote: You have other issues with those still, namely that table locks are not yet taken appropriately, so I'm not sure if this is worth worrying about

Re: [HACKERS] Re: [COMMITTERS] pgsql: Rework subtransaction commit protocol for hot standby.

2008-10-23 Thread Simon Riggs
On Thu, 2008-10-23 at 04:38 +0100, Simon Riggs wrote: That means that out of the four state transitions that are disallowed by the original coding of that Assert, you are now having to consider two as legal. I don't like that, and I like even less that it's not even trying to determine

Re: [HACKERS] Regression in IN( field, field, field ) performance

2008-10-23 Thread Tom Lane
Gregory Stark [EMAIL PROTECTED] writes: Tom Lane [EMAIL PROTECTED] writes: Works fine for me, eg I think he's looking for something like: 5 IN (col1,col2,col3) resulting in a bitmap or of three index scans of three different indexes on col1, col2, and col3. Ah, I see. It would be easy to

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Kris Jurka
On Thu, 23 Oct 2008, Tom Lane wrote: Well, aside from the gruntwork needed to convert all the core code that still uses the old APIs, there's the prospect of breaking extension modules that still use the old APIs. It's kind of annoying to have two copies of that code, but less annoying

Re: [HACKERS] Hot Standby utility and administrator functions

2008-10-23 Thread Simon Riggs
On Mon, 2008-10-20 at 10:25 +0100, Simon Riggs wrote: What else do we need? * pg_freeze_recovery() * pg_unfreeze_recovery() Two more functions pg_freeze_recovery_cleanup() pg_unfreeze_recovery_cleanup() These would allow recovery to continue normally, except for row removal operations

Re: [HACKERS] SSL cleanups/hostname verification

2008-10-23 Thread Bruce Momjian
Magnus Hagander wrote: Attached patch cleans up the certificate verification in libpq, and adds a configuration paraqmeter to control it. The new parameter is sslverify, and can be set to: Because SSL offers both encryption and authentication, I wonder if we should call this sslauthenticate.

Re: [HACKERS] Any reason to have heap_(de)formtuple?

2008-10-23 Thread Greg Stark
The sad thing us that I also did a patch for this and lost it. I think it wouldn't be too hard to convert all the call sites in the backend and provide a wrapper for other users. greg On 23 Oct 2008, at 08:59 PM, Kris Jurka [EMAIL PROTECTED] wrote: On Thu, 23 Oct 2008, Tom Lane wrote:

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Bruce Momjian
Julius Stroffek wrote: Hi All, we would like to start some work on improving the performance of PostgreSQL in a multi-CPU environment. Dano Vojtek is student at the Faculty of Mathematics and Physics of Charles university in Prague (http://www.mff.cuni.cz) and he is going to cover this

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Greg Smith
On Thu, 23 Oct 2008, Bruce Momjian wrote: I think the current plan is to use posix_advise() to allow parallel I/O, rather than async I/O becuase posix_advise() will require fewer code changes. These are not necessarily mutually exclusive designs. fadvise works fine on Linux, but as far as I

Re: [HACKERS] SSL cleanups/hostname verification

2008-10-23 Thread Magnus Hagander
Bruce Momjian wrote: Magnus Hagander wrote: Attached patch cleans up the certificate verification in libpq, and adds a configuration paraqmeter to control it. The new parameter is sslverify, and can be set to: Because SSL offers both encryption and authentication, I wonder if we should

[HACKERS] SSL README

2008-10-23 Thread Magnus Hagander
I notice that there is a src/backend/libpq/README.SSL that contains a couple of copied emails in it (it even contains our end-of-broadcast message string!) And it contains a reply to the mail, with quoted stuff! In general, this seem to be some hints about how to use things. Things that if we

Re: [HACKERS] SSL README

2008-10-23 Thread Alvaro Herrera
While you're cleaning up SSL, how about the thread with this email on it: 19212172.post%40talk.nabble.com -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Jonah H. Harris
On Thu, Oct 23, 2008 at 4:53 PM, Greg Smith [EMAIL PROTECTED] wrote: I think the current plan is to use posix_advise() to allow parallel I/O, rather than async I/O becuase posix_advise() will require fewer code changes. These are not necessarily mutually exclusive designs. fadvise works fine

Re: [HACKERS] SSL README

2008-10-23 Thread Bruce Momjian
Magnus Hagander wrote: I notice that there is a src/backend/libpq/README.SSL that contains a couple of copied emails in it (it even contains our end-of-broadcast message string!) And it contains a reply to the mail, with quoted stuff! In general, this seem to be some hints about how to use

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Bruce Momjian
Jonah H. Harris wrote: On Thu, Oct 23, 2008 at 4:53 PM, Greg Smith [EMAIL PROTECTED] wrote: I think the current plan is to use posix_advise() to allow parallel I/O, rather than async I/O becuase posix_advise() will require fewer code changes. These are not necessarily mutually exclusive

Re: [HACKERS] SSL README

2008-10-23 Thread Russell Smith
Alvaro Herrera wrote: While you're cleaning up SSL, how about the thread with this email on it: 19212172.post%40talk.nabble.com Yeah, I mentioned this to Magnus this morning (my time) and he said Bruce was compiling a patch in time for the next commit fest. I'm not sure where it's all

Re: [HACKERS] SSL README

2008-10-23 Thread Bruce Momjian
Russell Smith wrote: Alvaro Herrera wrote: While you're cleaning up SSL, how about the thread with this email on it: 19212172.post%40talk.nabble.com Yeah, I mentioned this to Magnus this morning (my time) and he said Bruce was compiling a patch in time for the next commit fest.

[HACKERS] Reducing the memory footprint of large sets of pending triggers

2008-10-23 Thread Tom Lane
We've occasionally talked about allowing pending-trigger-event lists to spill to disk when there get to be so many events that it's a memory problem. I'm not especially interested in doing that right now, but I noticed recently that we could alleviate the problem a lot by adopting a more compact

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Greg Stark
I couldn't get async I/O to work on Linux. That is it worked but performed the same as reading one block at a time. On solaris the situation is reversed. In what way is fadvise a kludge? greg On 24 Oct 2008, at 01:44 AM, Bruce Momjian [EMAIL PROTECTED] wrote: Jonah H. Harris wrote: On

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Bruce Momjian
Greg Stark wrote: I couldn't get async I/O to work on Linux. That is it worked but performed the same as reading one block at a time. On solaris the situation is reversed. In what way is fadvise a kludge? I think he is saying AIO gives us more flexibility, but I am unsure we need it.

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Jonah H. Harris
On Thu, Oct 23, 2008 at 8:44 PM, Bruce Momjian [EMAIL PROTECTED] wrote: True, it is a kludge but if it gives us 95% of the benfit with 10% of the code, it is a win. I'd say, optimistically, maybe 30-45% the benefit over a proper multi-block read using O_DIRECT. -- Jonah H. Harris, Senior DBA

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Jonah H. Harris
On Thu, Oct 23, 2008 at 10:36 PM, Greg Stark [EMAIL PROTECTED] wrote: I couldn't get async I/O to work on Linux. That is it worked but performed the same as reading one block at a time. On solaris the situation is reversed. Hmm, then obviously you did something wrong, because my tests showed

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Tom Lane
Jonah H. Harris [EMAIL PROTECTED] writes: On Thu, Oct 23, 2008 at 10:36 PM, Greg Stark In what way is fadvise a kludge? non-portable, requires more user-to-system CPU, ... need I go on? I'd be interested to know which of these proposals you claim *is* portable. The single biggest reason to

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Jonah H. Harris
On Fri, Oct 24, 2008 at 12:42 AM, Tom Lane [EMAIL PROTECTED] wrote: non-portable, requires more user-to-system CPU, ... need I go on? I'd be interested to know which of these proposals you claim *is* portable. The single biggest reason to reject 'em all is that they aren't. Yes, that was

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Greg Stark
On 24 Oct 2008, at 04:31 AM, Jonah H. Harris [EMAIL PROTECTED] wrote: On Thu, Oct 23, 2008 at 10:36 PM, Greg Stark [EMAIL PROTECTED] wrote: I couldn't get async I/O to work on Linux. That is it worked but performed the same as reading one block at a time. On solaris the situation is

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Greg Stark
Based on what? I did test this and posted the data. The results I posted showed that posix_fadvise on Linux performed nearly as well on Linux as async I/O on Solaris on identical hardware. More importantly it scaled with the number if drives. A 15 drive array gets about 15x the performance

Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-23 Thread Greg Stark
We did discuss this in Ottawa and I beleive your comment was the hint is in the name referring to posix_fadvise. In any case both aio and posix_fadvise are specified by posix so I don't see either as a problem on that front. I don't think we can ignore any longer that we effectively can't