Sunday, January 23. 2011
Another step towards easier backups Posted by Magnus Hagander in PostgreSQL at 12:46
Today I committed the first version of a new PostgreSQL tool, pg_basebackup. The backend support was committed a couple of weeks back, but this is the first actual frontend.
The goal of this tool is to make base backups easier to create, because they are unnecessarily complex in a lot of cases. Base backups are also used as the foundation for setting up streaming replication slaves in PostgreSQL, so the tool will be quite useful there as well. The most common way of taking a base backup today is something like (don't run this straight off, it's not tested, there are likely typos):
And when you're setting up a replication slave, it might look something like this:
There are obvious variations - for example, I come across a lot of cases where people don't bother checking exit codes. Particularly for the backups, this is really dangerous.
Now, with the new tool, both these cases become a lot simpler:
That simple. -Ft makes the system write the output as a tarfile (actually, multiple tar files if you have multiple tablespaces, something the "old style" examples up top don't take into account). -Z enables gzip compression. The rest should be obvious...In the second example - replication - you don't want a tarfile, and you don't want it on the same machine. Again, both are easily handled:
That's it. You can also add -P to get a progress report (which you can normally not get out of tar or rsync, except on an individual file basis), and a host of other options.
This is not going to be a tool that suits everybody. The current method is complex, but it is also fantastically flexible, letting you set things up in very environment specific ways. That is why we are absolutely not removing any of the old ways, this is just an additional way to do it.
If you grab a current snapshot, you will have tool available in the bin directory, and it will of course also be included in the next alpha version of 9.1. Testing and feedback is much appreciated!There are obviously things left to do to make this even better. A few of the things being worked on are:
Tuesday, January 18. 2011
pgindent vs dash Posted by Magnus Hagander in PostgreSQL at 12:13
For those who don't know, pgindent is the tool used to indent the source code of PostgreSQL. dash is the shell that ships as /bin/sh on at least Ubuntu.
pgindent requires indent from BSD (we use a patched version from NetBSD, the source is available on the PostgreSQL ftp site), and specifically does not work with GNU indent. Guess what Ubuntu ships with.
The solution is of course a small script that runs BSD indent from a different directory, and also points out the typedefs.list file from the PostgreSQL git repo. Something like this:
Spot the error? Yeah, that calls /bin/sh, which is dash. Which gives some really interesting results with pgindent, none of which are what you expect.
So if you run pgindent through a script like this, be sure to use /bin/bash and not /bin/sh!
Tuesday, December 28. 2010
Feedback from PGDay.EU the final ... Posted by Magnus Hagander in PostgreSQL at 11:57
The big change for PGDay.EU this year really was the switch from a university venue (first Monash University in Prato, then ParisTech in Paris) to a hotel venue (The Millennium Hotel in Stuttgart). We believe that much of the rest of the conference was an improvement over previous years - but it was an incremental improvement, whereas the change of venue was rather drastic. Looking at the feedback on this, I think we can conclude that this change was in general a positive one:
We're seeing a total of 75% who rate the venue as a 4 or a 5. Looking at the freetext comments, a large majority of them are very positive, but there are a few ones that stand out:
Amongst the positive ones we find a large number of comments saying that the "integrated venue" or "all inclusive" venue was a great step up.
Closely related to the venue, is the food. Unlike the big north American conferences PGCon and PG-East/West, we have for the past two years tried to provide proper lunches and not just sandwiches/boxed lunches. This obviously costs more money, but we believe it's worth it, and we think our visitors do. Last year we had a catering firm bring us assorted food, mainly cold cuts, at the conference venue, and this year we got proper lunch buffets (including multiple choices for dessert, of course..) at one of the hotel restaurants. I think the ratings speak for themselves - I would encourage those other conferences to look into improving their lunches as well!
A full 82% rated the food as 4 or 5. In the end, the cost for paying for a lunch "on ones own bill" would probably have cost more than half the conference fee - so we think we managed to provide some very good value. In fact, several people rated the food as being the best part of the conference(!)
There was, however, one person who said the food was one of the worst things about the conference - if you recognize that was you, we would very much like to know exactly why (no details were included) - please send me an email or write a comment here!
A few people commented on the large amount of food left over from lunch on at least one of the days - it is up to the hotel to decide what to do about that, but it is our belief that they do something "reasonable" with it - and not just throw it away. We know that the caterers last year delivered all leftovers to a nearby homeless shelter, for example. For next year, we will attempt to again get a specification from the catering/restaurant as to what happens to leftovers.
We feel that the overwhelming majority of our visitors found the changes an improvement, and we will therefor pursue something similar as our primary option for next year. We are always interested in improving further, of course, so if you have any other ideas - let us know! The final question we asked about the venue was where to hold the conference next year. Many were quite ambiguous in their suggestions ("big city in Europe" is in, "Hawaii" is out because we want to stick to Europe). Summarizing what we could gave us the following:
The final part of our evaluation was considering the conference website and registration:
In general these are very good rates. I'm happy to see that more than 50% rate the website overall experience as 4 or 5 - that's a much better rating than it's being given by the people who edit the content on it! Same for registration, with very few people rating it really low. There's clearly some room for improvement though:
In summary, here are some reasons in graphical and textual forms why you should already put attendance to next years PostgreSQL Conference Europe in your budget:
That concludes my summaries of the feedback from this years PGDay.EU conference. If your specific comments haven't been called out here, don't worry - we still read them all and will consider them all for next year!
Finally, thanks again to all who helped make this conference great!
See you again next year!
Wednesday, December 22. 2010
Feedback from PGDay.EU - the speakers Posted by Magnus Hagander in PostgreSQL at 15:37
The next issue of my "pie-chart-overflow blog posts about PGDay feedback" is about our speakers. The speakers are, if that's not obvious, the reason that people come to the conference. Having good speakers is an absolute requirement if we want to keep up the quality of the conference. Other things like venue and price are certainly important, but nothing compares to the actual content of the conference - which is provided by our speakers.
I'm very happy to say that we seem to have manage to keep the very high numbers for Speaker Quality that we had from last year (differing less than 3% which is well within the margin of error). The same goes for the scores our speakers got on their knowledge of the topic - indicating that we've managed to attract some of the most skilled speakers in the world. Which is not surprising given that in many cases, we the person speaking about a feature is actually the guy who wrote it. What is more surprising is that these same people are rated as very good speaker - which we all know isn't always true about your stereotypical developer.
Just like last year, we're not going to post the complete list of speaker ratings, given that they are easy to read wrong. But here is a list of our top speakers, excluding any that had less than 5 ratings. Any speakers who have fewer than 10 should be considered a very uncertain number, and I've again included the standard deviation to determine the uncertainty. We had a lot more speakers this year, so I have only included those scoring 4 or above this time around. Each speaker has received his own detailed score, of course.
The list based on Speaker Knowledge looks slightly different, but not very much. Given that our speaker knowledge has been rated even higher than speaker quality, I've only included those who scored 4.6 or higher (which is a fantastically high cutoff)
A great big thanks to all our speakers - you did a fantastic job.
We will need to work hard to keep up our recruiting of speakers for next years. If you were considering but decided not to submit a talk for some reason - please let us know why, so we can improve! Or if you have any ideas in general on our processes around this. For example, we had no female speakers at all this year - we know you're out there, and we certainly want you there, so what do we need to change to make this more interesting for you as a potential speaker? The same goes for other groups that we were missing of course: now is the time to let us know so we have the time to change things before next year!
Wednesday, December 22. 2010
Feedback from PGDay.EU - the contents Posted by Magnus Hagander in PostgreSQL at 09:53
This blog seems to be turning into a PGDay blog rather than a general PostgreSQL blog. But I promise I'll get back to some more technical content soon - or at least that I'll try.
A couple of days ago we closed the feedback system from PGDay.EU 2010, and have been busy tallying the result. It turns out that my constant nagging on people to please fill out the feedback worked - we got a lot more feedback this year than last year. That also means there's a lot more work in going through mainly all the freetext comments - that's the price I have to pay, I guess. In total we had around 60 people who left "full conference feedback", which is almost double from last year. It's still only just over 25% of the attendees, so it could certainly be even better yet. We also had 86 people who left session feedback (this is around 40% and a much better number of course) for a total of 570 session feedback entries.
So what did the feedback say - time for some pie charts! We've actually seen a slight decrease in the ratings for topic importance. This may well be because we've broadened the topics more. We're still seeing very good grades for content quality, which reinforces my feeling that our speakers deliver very valuable content to the attendees, and that the conference is well worth attending. (As a note to readers - I've had several people point out to me that german people are used to rating 1 being the highest and 5 being the lowest, so there may be some skewing in the voting because of this. Even though the pages very clearly stated that 5 is the highest, this is something we need to make even more clear for next year)
We spent a lot of time trying to put together the puzzle that is the schedule for so many talks over so short time. It turns out that we did a good job in general, but there was a large amount of overlap where people wanted to go to many talks at the same time. We also received a lot of comments in the freetext fields about this, and this is definitely something that we will consider for next year. It would probably have been better content-wise to have three tracks spread over three days (maybe not entirely complete) rather than four tracks over two days, but that would also have increased many of the costs with 33% which is a lot of money...
Of course, the "Hallway track" is a very important part of any conference like this, and this year we collected specific feedback on this side. I'm very happy to see that more than two thirds of our attendees rated the learning part of the hallway track as 4 or 5, and well over half found it a good way to connect with other people in the community!
If these numbers don't make you interested in next years PostgreSQL Conference Europe then, really, you're reading them wrong...
That's enough pie-charts for one post. I will follow this up with more feedback summary on our speakers and on our venue once it's ready.
Friday, November 26. 2010
pgday.eu registration deadline extended Posted by Magnus Hagander in PostgreSQL at 15:18
The registration deadline for pgday.eu has been extended. Instead of ending today, the new deadline is Saturday, December 4, 17:00 CET. There are, however, a few restrictions with this extension:
Once this second deadline expires on the December 4th, you are still welcome to attend the conference - but in this case, you have to pay the higher price for a pay at the door registration. Even if you choose this, we do appreciate if you register online first (choosing that rate), so we can prepare a badge and conference pack for you.
If you have any further questions, please contact us at email@example.com.
Thursday, November 25. 2010
PGDay.EU - where's your country? Posted by Magnus Hagander in PostgreSQL at 10:25
Initial numbers from our registration database for PGDay.EU 2010 is showing that we are expanding our international reach more than last year. In 2009, 60% of the attendees were from France, which is where the conference was held. This year the number of attendees from Germany is "down" to about 50%, meaning we have more people from other countries. The total number of countries is down one though - we have no registration from Nicaragua this year! Even our attendance from the US is up to three more people.
Pardon my horrible openoffice.org chart, but here is the current spread of attendees. Where does your country stack up? If it's not Germany, then it's not high enough - time to suggest/encourage/force/trick your friends and colleagues to register and attend! (And if it's Germany - hey, can you really let the French get to 60% last year and not beat them this year?)
Registration for PGDay.EU 2010 closes soon! Don't miss out on the biggest PostgreSQL event in Europe this year, and all the great presentations!
Monday, November 22. 2010
Make your picks - PGDay.EU 2010 Posted by Magnus Hagander in PostgreSQL at 20:00
PGDay Europe 2010 is drawing closer - only two weeks until kickoff! Some of the training is filled up, but we still have space for some more people on the general conference (and some of the training sessions). It's not too late - go register!
I'll be spending much of the time working with the conference administration, hopefully making things flow. But with a schedule like this, there are some sessions that I'm definitely not going to miss:
With this much great content, it's hard to choose - but those are my choices for PGDay. (I of course reserve the right to change my mind, depending on how late the speaker left from the party the day before)
What are yours?
And if you haven't registered yet, you still have a few more days. Don't miss your chance to attend the biggest PostgreSQL event in Europe this year! Registering is easy and quick - not to mention cheap!
Tuesday, November 2. 2010
Back to conferencing - PGWest Posted by Magnus Hagander in PostgreSQL at 23:13
Today is the first day of PG-West, also known as JDCon-west. After having about a week off to visit places and visit friends, I'm now back up in San Francisco for this conference, which will cover most of this week. It's a bigger conference than JDCon has been before - in most measures. It as more sessions than ever before - but you have to wonder who thought it was a good idea to have five parallel sessions. That's almost a guarantee that there will be more than one session you really want to go do. I'd rather have seen it in fewer tracks and spread over more time.
It's also bigger in attendees than before. Last I heard it was at 203 or something like that - just over 200. That means that for the first time, JDCon is actually larger than a PGDay.EU (that had just over 190 last year) - I'm sure being in a great location in central San Francisco helps with that, along with the fact that the economy is in a better place now than a year ago. We're still in the lead over time (we were well over 200 a couple of years back), but we're also both well beaten by the Brazilians. It' sets a good target for us to work towards!
The set of sessions looks really good, but as usual the hallway track is the one where much of the really good things happen. I missed this mornings tutorial sessions completely due to very interesting discussions outside. Hopefully the slides and notes and/or video will be available to look over once we're done. If you're tracking this from away, the twitter stream has some interesting comments - and will hopefully have more!
Speaking of conferences - if you haven't already, now's a good time to register for pgday.eu. Particularly if you are planning to attend one of the training sessions - at least one of the sessions is already more than half sold out!
Tuesday, October 19. 2010
PGDay Europe 2010 Registration Open Posted by Magnus Hagander in PostgreSQL at 13:10
It's finally time - we've opened up for registrations for PGDay Europe 2010.
We are not finished with the schedule yet, so if you are looking for a specific talk, you'll have to wait a while longer. Work is in progress though - we've already notified some of our speakers that they are approved. However, if you submitted a talk and have not heard from us yet, it's not yet time to panic. The reason we haven't published a schedule yet is that we're working on ways to include more talks!
So why would you want to go register now, even though the schedule isn't posted yet? Well, first of all, the schedule is looking like it'll be at least as good as last year. We have several well known good speakers from the community showing up again, and also some fresh faces with interesting topics!
But more importantly, this year, we've added training for the first time. Training will run on the wednesday (the main conference being monday and tuesday). This training is *limited availability* (25 seats per session), and *extra cost*. You pay this at registration. And the seats are handed out on a first come/first serve basis. So if you want to attend the training, now is the time to register! The training schedule *is* final, so be sure not to pick two training sessions that run at the same time.
The conference this year will be held at the Millennium Hotel in Stuttgart. We do recommend that you reserve a room with that hotel, as we have a group rate there, and it's conveniently located (hint: no need to go outside to get from A to B). But using this hotel is not mandatory - you can book your room anywhere you like. However, it should be noted that *wireless internet* is only included if you booked a room *using our group rate*. If you don't, you can pre-purchase the access when you register, or you can solve it yourself for example using 3G data. We will *not* have the ability to provide or sell you wireless access unless you pre-purchase it!
With all that said, head off and register!
Magnus about PGConf.EU 2013 feedback results
Fri, 22.11.2013 10:38
We did ask such a question in the feedback, wihch can be con sidered "voting". So we do hav e the data about peoples [...]
Pavel Golub about PGConf.EU 2013 feedback results
Fri, 22.11.2013 08:41
Magnus what about next year co nference venue voting?
Matt Spencer about PostgreSQL vs 64-bit windows
Wed, 06.06.2012 05:23
I agree totally, the 64-bit ve rsion definitely solves the pr oblem if you need more memory. We need to gradually sh [...]
Jim Smithson about PostgreSQL vs 64-bit windows
Tue, 05.06.2012 07:04
Users who are challenged by th e memory taxing qualities of t he 64 bit should go back to us ing 32 bit. It offers sm [...]
Magnus Hagander about PostgreSQL vs 64-bit windows
Thu, 19.04.2012 08:22
You are missing the point - wh ich is exactly that the filesy stem level cache does not ha ve a lower cache hit rat [...]
Marcov about PostgreSQL vs 64-bit windows
Mon, 26.03.2012 19:57
Any VM base caching is limited to the maximal mappable addre ss space(which is about 4G in windows 64-bit, 3GB in 3 [...]
Magnus Hagander about Finding gaps in partitioned sequences
Mon, 06.02.2012 10:18
Hah, thanks for pointing that out. That's what I get for try ing to clean up the formatting when posting it...
mark about Finding gaps in partitioned sequences
Tue, 31.01.2012 19:01
thanks, sorry I should have no ticed that was the seq MINUS t he lag function. p.s. you example may have a typo [...]
Magnus Hagander about Finding gaps in partitioned sequences
Mon, 30.01.2012 17:25
No, there are no user defined functions in this. seq is the column name, then minus the o perator, then lag the bu [...]
mark about Finding gaps in partitioned sequences
Mon, 30.01.2012 17:23
what is seq-lag ? i assume thi s is a user defined func.