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Displaying posts with tag: database (reset)
You've Got to Fight for Your Invoker's Rights

This post is about a PL/SQL feature that doesn't get enough respect, "invoker's rights".First off, what's its real name? Depending on the source, you'll see the feature name spelled "invoker's rights", "invokers' rights", or "invoker rights". That makes a difference -- you'll get different results in Google depending on what combination of singular, plural, and possessive you use. And to be

2009: Waiting to Exhale

Lots of blogs list a bunch of stuff that happened in the year just past, and I have done a year-in-review post before, but in looking back at posts on this blog and elsewhere, what strikes me most is not the big achievements that took place in technology in 2008, but rather the questions that remain unanswered. So much got started in 2008 — I’m really excited to see what happens with it all in 2009!

Cloud Computing

Technically, the various utility or ‘cloud’ computing initiatives started prior to 2008, but in my observation, they gained more traction in 2008 than at any other time. At the beginning of 2008, I was using Amazon’s S3, and testing to expand into more wide use of EC2 during my time as Technology Director for AddThis.com (pre-buyout). I was also investigating tons of other technologies that take different approaches to the higher-level problem these things all try to solve: owning, and housing (and …

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Database Connection Node Changes

Hi all,

As I mentioned in a previous blog entry, big changes are underway to the database connection connection node in NetBeans 7.0. If you look at the image above, you'll see what I mean. In the connection that is highlighted, no schema was selected when the connection was made, thus "default" is displayed as the schema.

When the schema is default, all schemas are displayed under the connection node when it is expanded. When you expand the schema, you'll see a familiar sight: the Tables, Views, and Procedures folders.

Individual database connections are also displayed as separate nodes below, even with default schemas.

Be sure to stay tuned for changes.

Happy Holidays!

--James

Hard Loading – something to avoid.

Last week I got a question about sharding using our Spockproxy.  The question was how can I create a query for the proxy so it effectively runs:

/*in shard 1*/
SELECT * FROM table_a WHERE f_key IN (a, b, c);

UNION

/*in shard 2*/
SELECT * FROM table_a WHERE f_key IN (d, e, f);

By design our proxy will not do this.  The whole point is to hide the sharding from the application.  Given a query it will either send the same query to all the shards and combine the results or only send that query to one shard when it can figure out that the results(s) can only come from one shard (because you specified the shard key in the where clause).

I did figure out a way it could be done using views but would this ever be desirable?  

Like “Hard Coding” where values are built into the code of your application I’ll call this technique “Hard …

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The Humble COUNT( ) Function

Here's another ode to a small but fundamental aspect of Oracle, following the same theme as The Humble IF Statement. This time, let's look at the COUNT( ) function. I think when you look at it the right way, it opens up the whole story about database performance.What's the first thing you do when poking around an unfamiliar system? I'll bet it involves SELECT COUNT(*) queries in one way or

Percona Offers InnoDB Replacement

Open source the way it ought to be. Today, Percona announced a replacement for InnoDB that improves performance and fixes bugs. The new engine is called XtraDB.

According to Vadim at Percona:

It's 100% backwards-compatible with standard InnoDB, so you can use it as a drop-in replacement in your current environment. It is designed to scale better on modern hardware, and includes a variety of other features useful in high performance environments.

The release is pure GPL (v2) and commercial support is available from Percona. If percona keeps this up, they just might become the new MySQL.

The source is available from Launchpad and from …

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Open Source Technology US Conference Calendar

One of the best ways to keep up with your field and network at the same time is to attend conferences. It’s one of the things I look forward to every year. After learning that O’Reilly has decided to commit blasphemy and *not* hold OSCON in Portland, Oregon the same week as the Oregon Brewers Festival, I was inspired to look around at what other conferences I might attend in 2009. Turns out, this is a huge pain in the ass, because I can’t find a single, central place that lists all of the conferences I’m likely to be interested in.

So… I created a public Google Calendar. It’s called “US Technical Conferences”. It needs more conferences, but I’ve listed the interesting ones I found. In order to keep the calendar from getting overwhelmingly crowded, I’ve decided that conferences on the list should:

  • Deal with open source technology in some way. This is purposely broad.
  • Be at least 3 days in …
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How Are You Staffing Your Startup?

I have, in the past, worked for startups of varying forms. I worked for a spinoff that ultimately failed but had the most awesome product I’ve ever seen (neural networks were involved, need I say more?), I helped a buddy very early on with his startup, which did great until angel investors crept in, destroyed his vision, and failed completely to understand the Long Tail vision my buddy was trying to achieve, and I worked for a web 2.0 startup which was pretty successful, and was subsequently purchased… by another startup!

Working in academia for 6 years also exposed me to people who are firing up businesses, or projects that accidentally become businesses, and some of those go nowhere, while others seem to be on the verge of NYSE listing now, while a year ago they were housed in the smallest office I’ve ever seen, using lawn furniture for their workstations.

Of course, I’ve also consulted for, and been interviewed by, a …

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Connecting to a MySQL Database

Hi all,

Today I'd like to continue a blog series in which I highlight Web application tutorials for NetBeans 6.5. A few changes have been made to tutorials, so be sure to check them out again.

This seventeenth entry in the series will cover the tutorial, Connecting to a MySQL Database.

This document demonstrates how to set up a connection to a MySQL database from NetBeans IDE 6.5. Once connected, you can begin working with MySQL in the IDE's Database Explorer by creating new databases and tables, populating tables with data, and running SQL queries on database structures and content. This tutorial is designed for beginners with a basic understanding of database management, who want to apply their knowledge to working with MySQL in NetBeans IDE.

This is great for learning how NetBeans and MySQL can be used together.

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Prepared Statements Killed My Database

In two separate instances, prepared statements used up all my database's connections and completely locked it. To the point that we had to restart the mysql server and in the other case, physically reset the server (not something you usually do with linux servers).
Apparently, one table had a read lock on it, which made the prepared statement wait a bit too long and it decided to flood the database connections till it would got an answer. Only the table was still locked and the database came to a screeching halt. The last thing I saw on my screen was a bunch of the same prepared statement on my process list screen, completely taking up all the slots and then.... I lost my connection to see the process list.
I don't really understand how the perl script and php page that ran the prepared statement could be so aggressive or where was it defined to continue opening new connections till they got an answer.

This is definatly …

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