Feedback from PGDay.EU the final part - the venue and registration

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%25 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:

• Several people mentioned it was bad that the two sets of rooms (Berlin vs non-Berlin rooms) were very far apart. This is definitely something that we noted, and will attempt to avoid next year.
• A few people mentioned that it would be nice if the hotel was closer to the city center. This is definitely true - unfortunately, closer to the city center means higher prices. We hope to find something closer to a city center at a reasonable price next year - by making sure we start to look and book early enough.
• A few people commented that we shouldn't hold this in northern/central Europe in December due to weather (snow anyone?). Our goal is to move the conference back to an earlier date during the autumn - again, the main reason we ended up in December this year was that we started looking for a venue too late.
• A couple of people commented that the hotel room rates were too high at the Millennium. There were cheaper hotels around to use - but of course, those aren't as convenient. This wasn't helped by the fact that the hotel group rate dropped off the hotel website twice, causing some people to get their reservations at a higher rate.
• Isolated people commented that they did not like the hotel - "too big, unpersonal" and "feels like a prison".

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%25 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:

• Obviously, we see a bias towards Germany - since we were in Germany this time. However, we are only going back to Germany next year as a last resort - we want to move around. We will eventually come back to Germany of course - but not next year.
• Some people commented that they will not be able to attend in a country other than Germany because they wouldn't understand the language of the talks. To deal with this, we are considering adding non-local-or-english talks as well for next year independent of where it is - where German talks (along with French and maybe Spanish) would be included even if the conference isn't in Germany.
• Our Germany community is also looking into creating a specific PGDay Germany next year, which will be a smaller event focused on the local market - something we as PostgreSQL Europe will help and encourage.
• I'm surprised to find Stockholm so high up on the list - I promise I didn't put any of those votes in there myself!
• It's good to note that all the cities having 2 or more suggestions were already on our list of places to look at for next year.
• We will consider this input and start looking for venues. This time we will not attempt to decide and announce a city first and find a venue later, we'll do it in the other order.

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%25 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:

• A few people commented they wanted non-paypal registration options. While the paypal system we use actually allow you to do a credit card payment without the need to sign up for paypal (which some people did not realize and thus sent us an email before registering asking about it), not everybody has a credit card (this is not America - or Sweden). We'd be very happy to hear suggestions for what to do here though - we've looked at many different options, and paypal turned out to be by far the best one. We need something that supports automation and is reasonably fast. We did also support bank transfer in extraordinary cases - but that's not something that can be automated (unless you are a much bigger customer to the bank than we are), and it takes a long time for some payments, since they have to cross borders. So - any suggestions are welcome, and our core registration system is designed to support multiple payment methods.
• Nobody actually wrote in the conference feedback that we lack a good interface for bulk registration, but we are aware of this - we had a few (less than 10 in total) entities wanting to register more than 2-3 persons at the same time for a single invoice, and our current system does not provide a reasonable way of dealing with this. This is definitely something we need to work on for next year.
• It's been suggested we add a "skill level" entry to each talk, to make it easier for an attendee to know if it's a beginner or advanced talk. This is definitely something we'll look at doing for next year.
• One suggestion is we include a full list of all attendees including their email address in the conference handouts, to make it easier to contact each other. This is not something we're going to do as a general thing, since we don't want to go distributing such lists. But we may consider adding it as an opt-in feature, where you can choose on registration if you want to be included in such a list.
• Several people suggested adding videos of the talks - either as realtime streaming or as downloadables. We're not likely to add a real-time streaming, but we are considering doing talk recording. It does add a fairly large amount of work though, so we'll be needing more volunteers to cope with it...
• We need to make it more clear that 5 is the best and 1 is the worst on the feedback forms. We know a few people filled them in wrong (we hope it meant they gave us bad rates when they meant good, but we don't know that), and it was also mentioned in the feedback.

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:

Freetext comments: * "The overall organization of that event was excellent." * "Very good organization, great people, interesting talks, vibrant community in general. Lots of core dev presents, high level of knowledge." * "Great organization from beginning (registration at the website, information prior to the event), arriving and registering (internet access already available, great t-shirt and backpack) to the conference itself (sessions, warning speakers about how much time is left), good food and drinks at the breaks and at lunch. Kudos to the organizers and everyone who helped make this happen." * "I think the organisation was perfect. There where many people and all know where they had to go to." * "The huge amount of information, inspiration and positive energy. Actually I hacked my first patch on the way back." * "The people especially the staff :) Both keynotes were stimulating good dsicussions with my peers" * "Very good conference. I felt really cosy there. As a noob to PG, I got a lot of information and I lost the fear of asking the experts (either on the mailing list or on IRC)." * "The organization was really great. Maybe the best PostgreSQL conference I've attended so far."

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!

Feedback from PGDay.EU - the speakers

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%25 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.

Place | Speaker | Quality Score | Standard deviation | Number of votes 1 | Dimitri Fontaine | 4.8 | 0.5 | 8 2 | Mason Sharp | 4.7 | 0.9 | 11 2 | Magnus Hagander | 4.7 | 0.7 | 29 4 | Simon Riggs | 4.6 | 0.7 | 52 4 | Simon Phipps | 4.6 | 0.9 | 45 6 | Andreas Scherbaum | 4.5 | 0.7 | 34 6 | Ed Boyajian | 4.5 | 1.1 | 33 8 | Bruce Momjian | 4.4 | 0.9 | 54 8 | Gianni Ciolli | 4.4 | 0.8 | 38 8 | Tim Bunce | 4.4 | 1.0 | 10 11 | Jan Aleman | 4.2 | 1.0 | 11 12 | Tim Child | 4.1 | 0.8 | 9 12 | Michael Meskes | 4.1 | 1.2 | 10 14 | Bernd Helmle | 4.0 | 0.6 | 6 14 | Heikki Linnakangas | 4.0 | 0.8 | 30 14 | Linas Virbalas | 4.0 | 0.9 | 10

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)

Place | Speaker | Knowledge Score | Standard deviation | Number of votes 1 | Tim Child | 5 | 0 | 9 2 | Joe Conway | 4.9 | 0.3 | 10 3 | Simon Riggs | 4.8 | 0.7 | 52 3 | Linas Virbalas | 4.8 | 0.4 | 9 3 | Magnus Hagander | 4.8 | 0.8 | 29 3 | Dimitri Fontaine | 4.8 | 0.5 | 8 7 | Andreas Scherbaum | 4.7 | 0.8 | 34 7 | Bruce Momjian | 4.7 | 1.0 | 53 9 | Mason Sharp | 4.6 | 1.2 | 11 9 | Heikki Linnakangas | 4.6 | 0.8 | 30 9 | Simon Phipps | 4.6 | 1.0 | 45 9 | Gianni Ciolli | 4.6 | 0.8 | 38 9 | Tim Bunce | 4.6 | 1.3 | 10 9 | David Fetter | 4.6 | 0.6 | 16

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!

Feedback from PGDay.EU - the contents

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%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%25 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%25 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.

pgday.eu registration deadline extended

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:

• After today, November 26th at midnight, we will only be able to process creditcard/paypal payments, or cash payments at the registration desk.
• After 17:00 CET today, November 26, the pre-paid discounted internet access for people not staying at the hotel will no longer be available. Internet access is still included in your room rate if you book with the PGEUROPE group rate.

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 contact@pgday.eu.

PGDay.EU - where's your country?

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%25 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%25, 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%25 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!

Make your picks - PGDay.EU 2010

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:

• The keynote, of course. Simon Phipps is a well known and very experienced Open Source speaker and worker. He'll be talking about "Back to the Future of Open Source", and it will be very interesting to hear his perspective on this, having been on the inside of for example Sun.
• Play chess against PostgreSQL (and get beaten) with Gianni Colli. You just need to read the title, of course I have to see it :-) Unfortunately it's up against PgOpenCL, but that's what happens when you have so many good talks.
• I think I can skip out of Simon Riggs talk about replication - I need to have my class for Wednesday ready before this anyway. But I highly recommend it to anybody who is planning to deploy the 9.0 replication features.
• That afternoon I'll be busy with the conference, and won't get to go to any of the talks... I'll definitely miss the Concurrency talk, the clustering and the psycopg one.
• Tuesday, I can't quite decide between Developing PostgreSQL performance or Graph Constraints, and Why You Care. But we put two such great talks early in the morning to make sure everybody gets up!
• Next I'd go to Stefans talk about benchmarking, but it's in German, so I think I'm better off not doing that. It'll be the case-study of the large deployment that Bull did for the French social services instead.
• Before lunch, I think it'll be Postgres-XC. I've been to a lot of conferences now where Mason has held a talk about this, and never actually managed to see one...
• After lunch, I'm again stuck at doing work (sheesh). If you haven't seen it already, I recommend Bruce's MVCC talk. There are other good ones as well, of course, but Bruce does a very good "deep introduction" to PostgreSQL's implementation of MVCC.
• Obviously there's no skipping out on the closing keynote. Ed usually does a good job - I expect no less this time.

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!

Back to conferencing - PGWest

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!

PGDay Europe 2010 Registration Open

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!

Monitoring streaming replication lag

Once you've set up the great new Streaming Replication with Hot Standby in PostgreSQL 9.0, you need to somehow monitor it. I've created a simple Munin plugin to graph the lag between the master and the slave, and also the lag between receiving and applying on the slave. It's available on my github page, and will likely also be included in the next Munin version. If you are using SR and Munin (or just SR and want to graph it), please try it out and let me know if there are issues with it - it could certainly do with some more testing.

PostgreSQL - now on git!

So it finally happened. The official PostgreSQL master source tree is now managed in git, instead of cvs. This means, amongst other things, that the worlds most advanced open source database now has a version control system with.. eh. atomic commits!

Like the first run, this one had some issues with it, but it was smaller and resolved in time not to have to roll back. This time, it turned out that the cvs version that ships in Debian GNU/Linux comes with patches that change the default date format to the ISO standard. But since one of our main requirements on the conversion was to be able to faithfully represent the old versions of the code, this broke every single file - since we used CVS keyword expansion in the old tree. Once we found this, it was a simple case of adding the DateFormat=old parameter to the CVS config file and re-run the whole conversion - which took several hours.

A lot of work went into making the repository conversion correct. Some of this was due to issues in the toolchain used - many thanks to Michael Haggerty and Max Bowsher for getting those fixed and explaining some of the behaviors of the software for us. In the end, a number of things needed to be changed in our existing CVS repository to make it migrate properly. Tom Lane provided a big patch to apply to the CVS repository itself prior to the conversion that cleaned most of those up - you can find a copy of it my github page if you're interested.

With this patch applied, we managed a conversion that was very close to the original repository. I personally think this is only because the PostgreSQL project has been very careful about how it deals with it's CVS repository - using it in a fairly simple way. And even with that, we had a number of issues - such as tags moved "after the fact", and branches created off partial checkouts. A fair number of the issues were simply because CVS doesn't have ways to represent everything in a reasonable way, such as issues when a file was deleted, re-added, deleted again, and mix this over different branches.

Git obviously deals with this better, and hopefully we'll have no such issues creeping into the new repository. However, the PostgreSQL project will be sticking with our "conservative approach" to source control - at least for the time being. For this reason, we are restricting what committers can use within git. We still allow any developers (and committers) to use whatever parts of git they want as they develop, but for commits going into the main tree, we are making a number of restrictions:

• We will not allow merge commits. The PostgreSQL project doesn't follow the "git workflow" - we generally develop our patches on the master branch, and then back-patch to released stable branches for important bugs. We will continue doing this as separate commits and not using merges, thus keeping history linear.
• We will not use the author field in git to tag it with the patches original author (even in the few cases when the patch is actually authored by a single person). Instead, we will require that author and committer are always set to the same thing, and we will then credit the author(s) (along with the reviewer(s)) in the commit message, just like we've done before.
• As a follow-on to that requirement, we will require that all committers are the ones registered with the project, using the same name and address on all commits. So even if a patch is developed on a topic branch on say github, it will get collapsed into a single commit (or maybe a couple, depending on size) tagged with the committers name on that.

There has been a lot of discussion around this, and this is how the PostgreSQL project has worked and wants to continue working. We may change this sometime in the future, but not now - we are only changing the tool, and not the workflow.

To enforce these requirements, I've developed a policy hook for our git server that makes sure we don't make the mistake. It's up on my github page, along with the script we use to generate commit mails to the pgsql-committers list that look just the way we want them to.

What does this mean for you as a PostgreSQL user? Really, nothing at all.

What does this mean for you as a PostgreSQL patch developer? Not much. If you did your work off the cvs-to-git mirror, you need to do a new clone. This repository is converted from scratch, so the old one is not valid anymore. We still encourage you to use for example github if you want to do your development there, but the patch submission process remains the same - send a context style diff to the pgsql-hackers mailinglist.

What does this mean for you as a buildfarm-animal maintainer? You need to reconfigure it to use git. I expect Andrew to post instructions on exactly what to do, and keep track of who hasn't done it ;)

Thanks and Well done to all the people involved in making this happen!