Photo: Teradata.

What: Shares of Teradata (TDC -1.14%) fell more than 15% on Thursday, at one point dipping as low as 19% below Wednesday's closing price.

So what: The maker of large-scale data analysis tools reported third-quarter results in the pre-market hours. Revenues fell 9% year over year, fighting a heavy currency exchange headwind. In constant currency, sales would have decreased by 3%. GAAP earnings declined 8% to $0.55 per diluted share.

Looking ahead, management now expects full-year sales of roughly $2.54 billion, down 7% from fiscal year 2014. GAAP earnings in 2015 should work out to a net loss of $0.61 per share. Adjusted earnings, which remove items such as a $340 million goodwill writedown in the second quarter, should stop near a positive $2.10 per share.

Three months ago, the full-year revenue outlook called was centered at $2.61 billion. The GAAP net loss was seen heading toward $0.47 per share and the adjusted bottom-line tally was aimed at $2.35 per share. In other words, the second half of Teradata's fiscal year isn't working out according to plan.

Now what: The currency exchange effect was large in the third quarter, but roughly in line with the expectations management set in their July guidance. So the actual surprise here must stem from other sources.

Teradata's management seem to feel the same way, and are taking action to turn the ship around.

Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

The company is now selling its marketing applications business, focusing its assets and efforts exclusively on data and analytics operations instead. Teradata is still looking for a buyer, but hopes to record an operating income boost of $120 million next year from exiting this market. To put that target into perspective, a $120 million bonus would have lifted Teradata's operating income in 2014 by 24%. At the moment, Teradata has recorded a year-to-date operating loss of $155 million, though that includes the $340 million goodwill hit mentioned above.

Fellow data analysis vendor Tableau Software (DATA) is set to report Q3 results after Thursday's closing bell. Tableau investors had their nerves rattled by Teradata's weak performance, and that stock temporarily fell as much as 5% on the eve of its own report. Look for that earnings release for further clues on the health of the global data analytics market.