Postgres Open, and What Makes a Good Talk
My last few blog posts have been all about scalability and performance, mostly because that's what I've been spending most of my time on these last few months. But I'm pleased to have another subject:...
View ArticleScalability, in Graphical Form, Analyzed
I'm at Surge, this week, where I just listened to Baron Schwartz give a talk about scalability and performance. As usual, Baron was careful to distinguish between performance (which is how fast it is)...
View ArticleCommitFest In Progress
I've seen a lot of articles lately about the great new features (and removed limitations) in PostgreSQL 9.1. Unless you're a regular reader of pgsql-hackers, you could almost forget about the fact...
View ArticleIndex-Only Scans: We've Got 'Em
Tom Lane committed a patch for index-only scans by myself and Ibrar Ahmed, which also incorporated some previous work by Heikki Linnakangas, after hacking on it some more himself. Woohoo!There is, of...
View ArticleDeadlocks
Last week, someone pinged me on instant messenger to ask about the following message, which their PostgreSQL instance had just produced:DETAIL: Process 22986 waits for ShareLock on transaction 939;...
View ArticlePostgreSQL Crash Debugging
As I mentioned in a previous blog post, I spend some of my time working in and with EnterpriseDB's support department. And what that means is that every customer I talk to has a problem, typically a...
View ArticleFast Counting
Since I wrote my previous blog entry on index-only scans, quite a bit of additional work has been done. Tom Lane cleaned up the code and improved the costing model, but possibly the most interesting...
View ArticleHint Bits
Heikki Linnakangas was doing some benchmarking last week and discovered something surprising: in some circumstances, unlogged tables were actually slower than permanent tables. Upon examination, he...
View ArticleUnsticking VACUUM
Every PostgreSQL release adds new features, but sometimes the key to a release has less to do with what you add than with what you take away. PostgreSQL 8.4, for example, removed the settings...
View ArticleLinux lseek scalability
I don't normally follow Linux kernel development, but I was pleased to hear (via Andres Freund) that the Linux kernel developers have committed a series of patches by Andi Kleen to reduce locking...
View ArticleWrite Scalability
Time flies when you're benchmarking. I noticed today that it's been over a month since my last blog post, so it's past time for an update. One of the great things about the PostgreSQL community is...
View ArticleLinux Memory Reporting
As much as I like Linux (and, really, I do: I ran Linux 0.99.something on my desktop in college, and wrote my class papers using vim and LaTeX), there are certain things about it that drive me crazy,...
View ArticleMy Patches Are Breeding
One of the great things about being a long-term contributor to an open source project like PostgreSQL is that you get to see other people take the stuff you've done and use it as a stepping stone to...
View ArticlePerformance and Scalability on IBM POWER7
I recently had a chance to run some benchmarks of PostgreSQL 9.2devel on an IBM POWER7 machine provided by IBM and hosted by Oregon State University's Open Source Lab. I'd like to run more tests, but...
View ArticleThe Git Workflow
When the PostgreSQL project decided to migrate to git, we decided not to allow merge commits. A number of people made comments, in a number of different fora, to the effect that we weren't following...
View ArticleThe Perils of Collation-Aware Comparisons
If you use psql's \l command to list all the databases in your PostgreSQL cluster, you'll notice a column in the output labelled "Collate"; on my system, that column has the value "en_US.UTF-8". This...
View ArticleFirst Results for Write Performance on IBM POWER7
In a previous blog post, I posted some SELECT-only pgbench results on IBM POWER7, and promised to post read-write results when I had them. That took a little longer than expected due to periodic...
View ArticleSecurity Barrier Views
People sometimes want to use PostgreSQL to implement row-level security, and historically it has not been very easy to do that securely. You can try to do it by creating a view which exposes just some...
View ArticleTuning shared_buffers and wal_buffers
I spend a lot of time answering questions about PostgreSQL, and one of the questions I get asked frequently is: how should I set shared_buffers? And, a bit less often, how should I set wal_buffers?...
View ArticleWhy Is My Database Corrupted?
Working in the support department (as I do) is a good way to hear lots of horror stories. From time to time, we get reports of what can only be described as database corruption: errors reading tables...
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