I have a Master's Degree in Pharmainformatics (which is quite IT oriented and different than regular Pharma Masters) from India. Since two years I am working on Microbial Genomics, which is Bioinformatics and now I have got a task of Database Management for next year. Is this shifting of fields increasing my exposure to different fields or am I just wasting time learning different things?
Shifting among several fields is definitely exposing you to different fields, and as the comments indicated, being an expert in more than one field is helpful for a successful career in academia. Answers to other questions on this site make it clear that shifting (or even completely changing fields) in the duration of an academic career is normal and advantageous.
For example, see Bitwise's advice here, where he says
Changing fields is very common in academia, especially at the PhD/postdoc transition. In many cases it is actually considered an advantage, since you can import your skills, expertise and a certain thought-process into a field in which many people do not have those skills. For example, many physicists, computer scientists and mathematicians have migrated to biology and have made significant contributions. In fact, there are even postdoctoral fellowships that specifically fund this type of field-change.
The question was specific to changing fields at the PhD/postdoc transition stage, but his advice holds at any stage of an academic career.