Verizon Sees Long Term Evolution

Verizon said this morning the company will launch its next-generation wireless broadband network, dubbed Long Term Evolution (LTE) after sometime in 2010, approximately a year after the large swath of C-block 700 MHz spectrum the company won in a recent FCC auction becomes available.

read more

More...

Google Offers Overviews Of Olympic Torch Relay

To some people, the Summer Olympics are little more than a nuisance - their television viewing schedules get messed up, don'tcha know.  But those who really enjoy the Games may be glad for the chance to watch the 2008 Olympic Torch Relay in Google Maps and Google Earth.

read more

More...

Merchant 7588 - Jenson USA - Shimano XT Shifters, 37% off! Affiliate Marketing Deal

Merchant 7588 - Jenson USA - Shimano XT Shifters, 37% off! has teamed up with Shareasale to now offer a new deal for its affiliates! Deal marketing description:

Shifter set to replace or upgrade your existing set up 37% off!!

For more information or to become an affiliate / reseller for this merchant offering, or to promote this exclusive Shareasale deal, please visit:
Merchant 7588 - Jenson USA - Shimano XT Shifters, 37% off!'s Affiliate Deals page...

Multi-Column IN clause - Unexpected MySQL Issue

We have an application which stores massive amount of urls. To save on indexes instead of using URL we index CRC32 of the URL which allows to find matching urls quickly. There is a bit of chance there would be some false positives but these are filtered out after reading the data so it works all pretty well.
If we just process urls one by one it works great:
PLAIN TEXT
SQL:

1. [FONT='Courier New', Courier, monospace]mysql> EXPLAIN SELECT url FROM 124pages.124pages WHERE url_crc=484036220 AND url="http://www.dell.com/";[/font]
2. [FONT='Courier New', Courier, monospace]+----+-------------+----------+------+---------------+---------+---------+-------+------+-------------+[/font]
3. [FONT='Courier New', Courier, monospace]| id | select_type | TABLE | type | possible_keys | KEY | key_len | ref | rows | Extra |[/font]
4. [FONT='Courier New', Courier, monospace]+----+-------------+----------+------+---------------+---------+---------+-------+------+-------------+[/font]
5. [FONT='Courier New', Courier, monospace]| 1 | SIMPLE | 124pages | ref | url_crc | url_crc | 4 | const | 1 | USING WHERE |[/font]
6. [FONT='Courier New', Courier, monospace]+----+-------------+----------+------+---------------+---------+---------+-------+------+-------------+[/font]
7. [FONT='Courier New', Courier, monospace]1 row IN SET (0.02 sec) [/font]

Handling URLs one by one is however not efficient if you're processing millions of them so we tried to do bulk fetches:
PLAIN TEXT
SQL:

1. [FONT='Courier New', Courier, monospace]mysql> EXPLAIN SELECT url FROM 106pages.106pages WHERE (url_crc, url) IN ((2752937066, 'http://members.aye.net/~gharris/blog/'), (3799762538, 'http://www.coxandforkum.com/'));[/font]
2. [FONT='Courier New', Courier, monospace]+----+-------------+----------+------+---------------+------+---------+------+-------+-------------+[/font]
3. [FONT='Courier New', Courier, monospace]| id | select_type | TABLE | type | possible_keys | KEY | key_len | ref | rows | Extra |[/font]
4. [FONT='Courier New', Courier, monospace]+----+-------------+----------+------+---------------+------+---------+------+-------+-------------+[/font]
5. [FONT='Courier New', Courier, monospace]| 1 | SIMPLE | 106pages | ALL | NULL | NULL | NULL | NULL | 14936 | USING WHERE |[/font]
6. [FONT='Courier New', Courier, monospace]+----+-------------+----------+------+---------------+------+---------+------+-------+-------------+[/font]
7. [FONT='Courier New', Courier, monospace]1 row IN SET (0.00 sec) [/font]

As you can see just using multiple column IN makes MySQL to pick doing full table scan in this case, even though the cardinality on the first column is almost perfect. I did some more testing and it looks like a bug or missing optimizer feature.
I should not be surprised though as multi-column in is not the most used MySQL feature out there.
For given application case we could simply rewrite query using more standard single column IN clause:
PLAIN TEXT
SQL:

1. [FONT='Courier New', Courier, monospace]mysql> EXPLAIN SELECT url FROM 106pages.106pages WHERE url_crc IN (2752937066,3799762538) AND url IN('http://members.aye.net/~gharris/blog/','http://www.coxandforkum.com/'); +----+-------------+----------+-------+---------------+---------+---------+------+------+-------------+[/font]
2. [FONT='Courier New', Courier, monospace]| id | select_type | TABLE | type | possible_keys | KEY | key_len | ref | rows | Extra |[/font]
3. [FONT='Courier New', Courier, monospace]+----+-------------+----------+-------+---------------+---------+---------+------+------+-------------+[/font]
4. [FONT='Courier New', Courier, monospace]| 1 | SIMPLE | 106pages | range | url_crc | url_crc | 4 | NULL | 2 | USING WHERE |[/font]
5. [FONT='Courier New', Courier, monospace]+----+-------------+----------+-------+---------------+---------+---------+------+------+-------------+[/font]
6. [FONT='Courier New', Courier, monospace]1 row IN SET (0.01 sec) [/font]

Theoretically speaking this query is not equivalent to the first one - because row having url_crc=2752937066 and url='http://www.coxandforkum.com/' would match it, while it should not. It however does not happen in our case as url_crc is functionally dependent on url so both queries are equivalent.
So we've got our work around and can forget about the issue and MySQL team gets yet another bug to deal with.
What worries me again is - this is very simple case which seems to to be generally broken which raises a question how good coverage MySQL tests have.
Entry posted by peter | No comment
Add to: | | | |


Multi-Column IN clause - Unexpected MySQL Issue - Read More...

Before the @ is important - another example

What you are seing in this image is the rollover Mail preview on the AOL homepage. Look at how much "trailblzaers" sticks out in that list. If you read this blog you know I hate webmaster@ in email marketing. This validates that point. This view is...

Steal this idea for your Newsletters - Mobile Friendly Version

This was the first time I have seen this at the top of an email: "Click here for the Wireless Version: URL" Brilliant idea by the AAAA. I personally would change it to "Mobile Friendly", wireless is kind of confusing. Most HTML email is...

Frequency: Caged or free range

During the EEC event in February in one of the sessions the topic was frequency of email. The panelists had discussed email frequency and how much is too much as well as capping the frequency of your email, i.e., only allow a subscriber to be...

Ten Comments on Housing (pfblogs.org)

David Merkel submits: 1) The big question is how much further will housing prices fall, and when will the turn come. My guess is 2010 for the bottom, and a further compression of prices of 15% on average. Now there are views more pessimistic than that, but I can't imagine that a 50% decline from the peak would not result in a depression-type scenario. (In that article, the UCLA projections are largely consistent with my views.) It is possible that we could overshoot to the downside. Markets do overshoot. At some level though, foreigners will find U.S. housing attractive as vacation/flight homes. After all, with the declining dollar, it is even cheaper to them. Businesses will buy up homes as rentals, only to sell them late, during the next boom. 2) But, the reconciliation process goes on, and with it, losses have to go somewhere. In some cases, the banks in foreclosure refuse to take the title. Wow, I guess the municipality auctions it off in that case, but I could be wrong. Or, they let the non-paying borrowers stay. I guess the banks do triage, and decide what offers the most value to act on first, given constraints in the courts, and constraints in their own resources. ...

Coming Up on the D4L Channel (pfblogs.org)

This chemical can be deadly. It will take the skin off your bones, was used during World War I as a pulmonary choking agent and it is used to make pesticides. Oh by the way, this chemical is in my home and it is probably in yours. But the question at hand is, can its manufacturer find its way into my dividend portfolio? Stay tuned, we'll find out...Now a word from our sponsor: The Ronco portfolio whopper-chopper slices and dices your portfolio into, not one, not two, but three unique views. You have your traditional capitalization slice, contemporary origin slice and, for no additional charge, we are throwing in a sector slice. All of this is available for the low, low price of free next week only.It's going to be a memorable week. Don't risk missing a minute of it. You can have it all packaged and delivered directly to you free by clicking here and subscribing to the D4L Channel.While waiting for this week's feature presentations, you may want to tune in to a few of these classic episodes:My Unique Investing ProcessPre-Screening Dividend Stocks - Part I Sometimes Things Aren't As They ...

How My Childhood Influences My Finances (pfblogs.org)

I share alot here at SingleGuyMoney. I've found that it is so much easier to share all of my financial details anonymously instead of telling a friend or family member about my debts or how much money I earn. Since I share so much of financial details here, I thought I'd share a little about my childhood and how it influences my financial decisions today. I grew up in a small town. By small, I mean one traffic light small. I never knew my father. He was killed in a car accident before I was even born. He did not have any type of insurance so the financial burden fell heavily on my mother. My mother did not finish high school and was working at a minimum wage job. Growing up, I remember not having alot. We were poor - very poor. I would get hand-me-down clothes from my cousins. I remember my mother receiving food stamps and walking in shoes with holes in them just so she could provide food for us. We lived in a rented house and the where the bathroom barely worked. The tub didn't work so we took baths in the sink. The toilet did ...

Losing my confidence over $600 reimbursement (pfblogs.org)

I thought I'd get a head start on the reimbursement paperwork for the $2,000 class to invest in my career. My other co-worker submitted his reimbursement and was expecting the check soon. Of course he didn't have to fill out the same paperwork - his boss just needed the receipt and it would come out of their budget.Last weekend I was anxiety ridden. I cried while sitting in the office studying for 6+ hours banging my head over math. I cried because for the last three months I've had no life. I barely saw my friends, barely had a social life, ate a lot of progresso soup, tuna salad sandwiches or deli sandwiches I made or bought at Subway but gained $2,000 worth of knowledge. I didn't go to Austin for SXSW to see bands and my friends. I called my therapist and took a lot of deep breaths. She reminded me I know more than I may think. I thought about all those hours studying in the office and the knowledge I've gained. I looked at my books and couldn't believe how much progress I've built. Then I stopped panicking and somehow gained a lot of confidence about my ...

We Hardly Knew Ye (pfblogs.org)

This post is not about "personal finance"—so skip it if you like. "Meeting" people on the other ends of computer screens has always struck me as a little bid odd and a little bit fascinating. I remember first experiencing it maybe 20 years ago. There was not much of a Web at the time, and there were certainly no blogs. Your computer interface was more or less a flashing cursor at the end of a line of text, essentially a DOS or UNIX style prompt (for those of you who have any clue what those are). It was more a novelty, and not that many people were really doing it or doing it regularly. And if you were wondering, no, there weren't any photos or avatars popping up next to someone's message. Now it's all pretty common. Lots of people would probably tell you they have numerous interactions with clients or other business contacts strictly through e-mail—nothing in person and maybe not much by phone either. Online dating has practically fallen into the mainstream. (For all I know, it already has, and I'm years out of date.) And people regularly share intimate details of their personal lives (or ...

Haugen's ST Governance Reform Bill may be resurrected for November

So says Erica Barnett in an article in yesterday's Stranger: conservatives and transit opponents may be moving to put a version of Sen. Haugen's governance reform measure on the ballot in November. As Erica points out, this would allow all of Washington state a vote on Sound Transit's future, not just the Puget Sound region.

To refresh your memory, Haugen's bill would change the definition of a regional transit authority into a regional transportation authority with responsibility for both roads and transit and run by an elected board rather than an appointed one. Since Sound Transit is a regional transit authority, it would be magically transformed into a completely new entity. Haugen's bill, according to my read, was a mixed bag--some bad, some good. I doubt a version taken to the ballot by conservatives would include much of the good, and would definitely have lots more bad.

At the Slog, Josh Feit questions why liberals can't muster similar ballot initiatives.

I asked that question myself a few months ago. It costs about $800,000 to sell a ballot initiative, according to one activist who was thinking about filing a initiative to mess with Tim Eyman's head. It would have been almost identical to Tim Eyman's initiative to force all tolling revenues to go to roads construction, except that it would have forced all tolling revenue to go to transit operations and roads. But with so much liberal money going to state and federal campaigns this year, pulling together that $800k would not be easy.

Sign the petition: Sound Transit in 2008

If you would like to see transit on the ballot this year, let ST know by signing this petition.

Here's the info from Transportation Choices Coalition:

SOUND TRANSIT ON THE BALLOT IN '08 - SIGN THE PETITION
Transportation Choices Coalition, Fuse, Environment Washington and Futurewise are working together to build support for Sound Transit to be back on the ballot in 2008.  With skyrocketing gas prices, more people stuck in traffic and the urgent need to slow global warming, we need real transit solutions now.  In a few weeks Sound Transit Board members will take the first steps to decide whether Sound Transit should be on the ballot in November this year.  The details of the final package are yet to be finalised but the proposed plan includes robust investments in light rail, commuter rail, and express bus service throughout the Puget Sound region as well as bike and pedestrian investments.

We will be delivering your signed petitions of support to the Sound Transit Board at their next meeting on Thursday, April 10.  Let's deliver a strong message to the board that Washingtonians care about real transportation solutions and want to see a great transit package on the ballot.