SAP

The following information might help you to decide. Oracle is not just a database provider, although, they are known for the database. They also have Oracle ERP, Oracle E-Business Suite Financials, etc.
On the other hand, SAP is not only a vendor for enterprise software such SAP ECC (previously known as SAP R/3) or SAP Business One. They now also have SAP HANA - in-memory database.
So you see, from the ground up both companies are alike. They both have databases (SAP only has SAP HANA in memory) and both have ERP software (among other solutions).
I for a fact know people that came from Oracle Financials into SAP Financials and vice-versa. The trick is to understand the business processes and get skills that are easily transferable from one technology to the other.
By the end of the day, a receivable is still a receivable regardless if you use SAP or Oracle.
Ps: Mind that a lot of SAP installations still run on top of Oracle databases. With SAP Hana, it is not certain that the landscape will remain unchanged in the next few years.

With the decreasing cost of data storage devices, companies are looking at the means to extract business intelligence from large databases and data warehouses. Data analytics (DA) is a process of examining data sets in order to draw conclusions about the information they contain, increasingly with the aid of specialised systems and software. Data analytics technologies and techniques are widely used in commercial industries to enable organisations to make more-informed business decisions and by scientists and researchers to verify or disprove scientific models, theories and hypotheses.
Big data platform is a type of IT solution that combines the features and capabilities of several big data application and utilities within a single solution. It is an enterprise-class IT platform that enables organisation in developing, deploying, operating and managing a big data infrastructure /environment. SAP HANA is one of the most popular Big Data platforms for Data Analytics. SAP HANA is an in-memory data platform that lets companies accelerate business processes, deliver more business intelligence, and simplify IT environment. By providing the foundation for all company data needs, SAP HANA removes the burden of maintaining separate legacy systems and siloed data, so the company can run live and make better business decisions in the new digital economy.
Currently, job opportunities in the field of Data Analytics are very high. There is a general shortage of DA experts in the market and their current salary level is very high. You may prefer SAP HANA over SAP FICO for better career opportunities.

Tally and SAP are the software which started as accounting software. Tally has been introduced by the Peutronics Pvt. Ltd. (currently known as Tally Solutions Pvt. Ltd). SAP software is owned by SAP, which is a Germany based company. Tally and SAP offer numerous products. However, they are primarily differentiated on the basis of ERP packages offered by them. Tally is a very basic type of ERP software, whereas SAP provides some advanced functionalities as an ERP package. Usage of tally software generally does not require professional training like in the case of SAP software. ERP provides more advanced features like data validation and data substitution. Third party software supports SAP is very high as compared to tally.