Database rights (i.e. rights gained for creating and organizing a collection of data independently of the rights of each entry) and the legalities of data mining are highly jurisdiction-dependent. In some jurisdictions you may not need to acquire a license for source data used for text mining (e.g. under the fair use doctrine). Others make no particular exceptions, so you would be bound by the CC-BY-SA license.
The CC-BY-SA 3.0 does not have any provisions for text mining. That license allows you to create and reproduce adaptions as long as these adaptions are licensed under the same license, or a later version of the same license. I am not sure whether the definition of adaptions can include databases or the results from text mining.
The CC-BY-SA 4.0 does consider Similar Rights incl. database rights, but you cannot directly use Wikipedia content under CC 4.0.
If your applicable jurisdictions allow the text mining you are in the clear. At the very least you want to avoid any infringement of copyrights and similar rights in your local jurisdiction, but you may also want to avoid infringement in jurisdictions where the data set will be published (effectively anywhere in the world). You may be able to license the database as a whole under whatever terms you choose, regardless of the licenses of entries within the database. Understanding how these laws interact may require professional legal help.
If the applicable jurisdictions only allow data mining for non-commercial purposes, you may not be able to perform the mining as the open-source project might be used commercially.
Absent any such permissions, you have to conform with the CC license you have received.
The CC-BY-SA 3.0 license does not directly allow for text mining. But the intention of the license clearly is to allow any derivative uses. We can therefore consider databases created through text mining of CC-BY-SA 3.0 content similar to adaptions of CC-BY-SA 3.0 content.
You may only publish these adaptions under a same or compatible license, in particular CC-BY-SA versions 3.0 or 4.0. Here, 4.0 may be preferable as it discusses database rights explicitly. Apache 2.0 or other permissive license are not compatible in this direction.
The Creative Commons wiki has a FAQ page about databases which may be worth reading.