David Fetter's blog

MVC Backups

Since Josh Drake has failed to allow comments on his very excellent blog, especially this post,I have to respond below.
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Tablespaces in a (nut)shell

Sometimes, you run across traces of LarryDB. One typical one is a profusion of tablespaces.

Until you solve that problem, you'll need to deal with them. Let's take setting up a warm standby.

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Part(ition)ing Glances

In an earlier installment, we learned about how to partition a
referenced table, which was good as far as it went. A commenter very
astutely pointed out that this didn't work with RETURNING, so I set
to work fixing that problem.

Here's what I came up with.

Continue reading "Part(ition)ing Glances"

psql, Paste, Perl: Pefficiency!

Enough alliteration already!

I was looking at Regina Obe's excellent piece on how to use psql to do an import on fixed-width data, and thought to myself, "self, how would you do this with fewer copies, just in case you happened across a few hundred gigs of data?"

Here's what I came up with:

Continue reading "psql, Paste, Perl: Pefficiency!"

File-driven Include and Exclude for pg_dump

So you're about to start replicating part of a database using Slony, and you'd rather not set up your replicas with all the extra cruft. You've made your list, but what to do with it?

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The Cloud Under the Lamp Post

A drunk is under a lamp post. It's late at night, and he is crawling
around on his hands and knees, searching frantically all over the tiny
pool of brilliant light it casts. A passer-by asks him, "what are you
doing?" He answers, "I'm looking for my keys." Pointing out into the
darkness, he continues, "I dropped them over there, but the light's
much better over here."

The joke is an old one, and illustrates an interesting truth about
human psychology.

What does this have to do with The Cloud, you ask?

Read on.

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Partly Cloudy, with a Very High Chance of FAIL

Everywhere you turn, it's "cloud" this, "cloud" that, "cloud" the other.
Public clouds, private clouds, hybrid
clouds, fluffy clouds...but somewhere in all that billowing haze,
there's an actual use case.

The people who designed cloud computing made certain explicit
trade-offs, some of which have been lost in all the hype. Given those
explicit trade-offs, your application is a candidate for "the cloud" in
general only if it has all of the following characteristics:

- Embarrassingly parallelizable
- Does not have bounded latency requirements
- Needs CPU much more than I/O
- Tolerant to partial data loss

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Free Your DBI-Link, and the Rest Will Follow

DBI-Link is now on Github!

Here's how I did it:
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Git + bash = win

Modern git comes with a great way to improve your life: git-completion.bash. To use it, just add the following to your .bashrc:

if [ -f /etc/bash_completion ]; then

    . /etc/bash_completion

    export PS1='\h:\u:\w $(__git_ps1 "(%s) ")'

fi

Once you've done this, any time you're in a git subdirectory, the branch name will appear in your PS1.
Any time you're not, it won't.
Simple!

Scripting psql for Fun and Profit

Profit?

Yes!
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Part(ition)ing Is Such Sweet Sorrow

There are excellent references on partitioning tables that depend on one table, but what happens when you need to partition the referenced table?

Let's find out!
Continue reading "Part(ition)ing Is Such Sweet Sorrow"

PostgreSQL Weekly News vs. Casa Donde

This week's PostgreSQL Weekly news may be rescheduled to Wednesday February 10, evening PST.

Thanks very much to whatever component failed at my home for this.

FOSDEM Starting

The herd of blue elephants is gathering for FOSDEM, including several talks in the main track.

I'd like to thank the FOSDEM for making it possible for me to attend this year.

More on this soon...

Adding Only New Rows (INSERT IGNORE, Done Right)

Let's say you have a table and a data set, and would like to add only those rows in your data set that aren't already in the table. There are hard ways, but here's an easy one.
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ORDER BY column_header

Ever wondered why you can't "just sort" by column when you're looking at an HTML table?
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