Sony TX5 has a 10.0MP 1/2.4-inch
(6.104 x 4.578 mm ) sized BSI-CMOS sensor and features Bionz processor. On the other hand, Olympus TG-860 has a 16.0MP 1/2.3-inch
(6.17 x 4.55 mm ) sized CMOS sensor and features TruePic VII processor.
Olympus TG-860's sensor provides 6MP more than Sony TX5's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the TX5 and TG-860 sensor size comparison.
Sony TX5 and Olympus TG-860 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.