TCS4F is an initiative by theoretical computer scientists who are concerned about that other major crisis of our time: climate change. We anticipate that the climate crisis will be a defining challenge of the decades to come, that it will require major changes at all levels of society to mitigate the harm that it will cause, and that researchers in theoretical computer science and in database theory, like all other actors, must be part of the solution and not part of the problem.

The TCS4F initiative proposes a manifesto to commit to a reduction of greenhouse gas emissions: following IPCC goals, the objective is to reduce by at least 50% before 2030 relative to pre-2020 levels. The manifesto is more than a simple expression of concern, because it is a pledge with concrete objectives. However, it does not prescribe specific measures, as we believe this discussion is not settled yet and the right steps to take can vary depending on everyone's practices.

The manifesto can be signed by individual researchers (like you, dear reader!), by research groups, and by organizers of conferences and workshops. Currently, over 90 researchers have signed it, including several database theory researchers. The goal of TCS4F is also to start organizing a community of concerned researchers, across theoretical computer science, to think about the issue of climate change and how to adjust what we do, in particular our travel habits.

We need your help to make this initiative a success and help theoretical CS, and database theory, lead the way towards a sustainable, carbon-neutral future:

• If you agree with our concerns and are ready to commit to reducing your carbon footprint, consider signing the manifesto. Signing is open to all researchers in theoretical CS in the broadest possible sense and of course to the whole database theory community.
• Advertise your support of the manifesto (e.g., by putting one of our badges on your webpage). Talk in your research teams and departments about the manifesto, and see if you can gather support for signing the manifesto collectively as a research group.
• If you are involved in conferences and workshops, start a discussion about the carbon footprint of the event, and whether the event could commit to the manifesto's goal. Indeed, as ICDT and SIGMOD/PODS are moving online this year because of the COVID-19 pandemic, it is a good time to discuss how our conferences could evolve towards more sustainable models.
• Spread the word about the issue of climate change and the TCS4F initiative, and encourage discussion of this important challenge in our communities.

As theoretical researchers, we are not used to discussing uncomfortable non-scientific questions like the effects of our activities on the world. However, we believe that the magnitude of the climate crisis obliges us to act now as a community. We are confident that great changes can be achieved if we do not limit our creativity to our specific research areas and also use it to re-think our way to do research.

* PODS Call For Submissions *
 
The Principles of Database Systems (PODS) symposium series, held in conjunction with the SIGMOD conference series, provides a premier annual forum for the communication of new advances in the theoretical foundations of data management, traditional or non-traditional (see https://databasetheory.org/PODS).
 
** Topics of Interest **
 
For the 40th edition, PODS continues to aim to broaden its scope, and calls for research papers providing original, substantial contributions along one or more of the following tracks:
 
- deep theoretical exploration of topical areas central to data management
- new formal frameworks that aim at providing a basis for deeper theoretical investigation of important emerging issues in data management
- validation of theoretical approaches from the lens of practical applicability in data management. Papers in this track should provide an experimental evaluation that gives new insight in established theories. Besides, they should provide a clear message to the database theory community as to which aspects need further (theoretical) investigation, based on the experimental findings.
 
Topics that fit the interests of the symposium include, but are not limited to:
 
- concurrency & recovery, distributed/parallel databases, cloud computing
- data and knowledge integration and exchange, data provenance, views and data warehouses,  - metadata management
- data-centric (business) process management, workflows, web services
- data management and machine learning
- data mining, information extraction, search
- data models, data structures, algorithms for data management
- data privacy and security, human-related data and ethics
- data streams
- design, semantics, query languages
- domain-specific databases (multi-media, scientific, spatial, temporal, text)
- graph databases and (semantic) Web data
- incompleteness, inconsistency, uncertainty in data management
- knowledge-enriched data management
- model theory, logics, algebras, computational complexity
 
** Submission Format **
 
Submitted papers must be formatted using the standard ACM proceedings stylesheet (https://www.acm.org/publications/proceedings-template) with the sigconf document class (\documentclass[sigconf]{acmart}). Submitted papers should be at most twelve pages, including bibliography. Additional details may be included in an appendix that should be incorporated at the submission time (online appendices are not allowed). However, such appendices will be read at the discretion of the program committee. Papers that are longer than twelve pages (including bibliography but excluding the appendix) or do not cohere with the ACM proceedings style risk rejection without consideration of their merits. PODS 2021 specifically encourages the submission of shorter papers as well as papers that make use of the full page allowance. The submission process will be through the Web at https://easychair.org/conferences/?conf=pods2021. Note that PODS does not use double-blind reviewing, and therefore PODS submissions should have the names and affiliations of authors listed on the paper.
The results of a submitted paper must be unpublished and not submitted elsewhere, including the formal proceedings of other symposia or workshops. Authors of an accepted paper will be expected to sign copyright release forms, and one author is expected to present it at the conference. PODS supports the open-access of published research. It is therefore expected that authors of accepted papers will make the final version of their papers also freely accessible on arXiv by the camera-ready deadline.

** Inclusion and Diversity in Writing **

We value Diversity and Inclusion in our community and professions. Both are important in our writing as well. Be mindful in your writing of not using language or examples that further the marginalization, stereotyping, or erasure of any group of people, especially historically marginalized and/or under-represented groups (URGs) in computing. Also, be vigilant and guard against unintentionally exclusionary examples. Reviewers will be empowered to monitor and demand changes if such issues arise. Going further, also consider actively raising the representation of URGs in your writing. Diversity of representation in writing is a simple but visible avenue to celebrate and ultimately help improve our community’s diversity.
Please visit this page for many examples of both exclusionary writing to avoid and inclusive writing that celebrates diversity to consider adopting: http://2021.sigmod.org/calls_papers_inclusion_and_diversity.shtml
 
** Important Dates **
 
FIRST SUBMISSION CYCLE:
July 02, 2020: Abstract submission
July 07, 2020: Paper submission
September 18, 2020: First notification
October 16, 2020: Revised submission
November 13, 2020: Final notification

SECOND SUBMISSION CYCLE:
December 13, 2020: Abstract submission
December 20, 2020: Paper submission
March 05, 2021: Notification

All deadlines end at 5 pm Pacific Time.

Conference dates: 20-25 June 2021 (Xi'an, China).

** Organization **

Chair
Reinhard Pichler (TU Wien, Austria)

Program Committee Members
Mahmoud Abo Khamis (Relational AI, USA)
Marcelo Arenas (Pontificia Universidad Católica de Chile, Chile)
Sepehr Assadi (Rutgers University, USA)
Marco Calautti (University of Trento, Italy)
Hubie Chen (Birkbeck, University of London, UK)
Edith Cohen (Google Research, USA and Tel Aviv University, Israel)
Claire David (LIGM, University Gustave Eiffel, France)
Alin Deutsch (University of California, San Diego, USA)
Diego Figueira (LaBRI, CNRS & Univ Bordeaux, France)
Martin Grohe (RWTH Aachen University, Germany)
Yazmin Angélica Ibáñez-García (Cardiff University, UK)
Batya Kenig  (University of Washington, USA)
Daniel Kifer (Pennsylvania State University, USA)
Jerzy Marcinkowski (University of Wrocław, Poland)
Frank Neven (Hasselt University, Belgium)
Matthias Niewerth (University of Bayreuth, Germany)
Rasmus Pagh (IT University of Copenhagen, Denmark)
Liat Peterfreund (CNRS, IRIF, Université de Paris, France)
Juan Reutter (Pontificia Universidad Católica de Chile, Chile)
Thomas Schwentick (TU Dortmund University, Germany)
Pierre Senellart (ENS, PSL University, France)
Srikanta Tirthapura (Apple Inc., and Iowa State University, USA)
Martín Ugarte (Millennium Institute Foundational Research on Data, Chile)
 
PODS General Chair
Leonid Libkin (University of Edinburgh, UK)
 
Proceedings Chair
Paolo Guagliardo (University of Edinburgh, UK)
 
Publicity Chair
Nofar Carmeli (Technion - Israel Institute of Technology, Israel)
 
** Awards **
 
Best Paper Award: An award will be given to the best submission, as judged by the program committee.
 
Best Student Paper Award: There will also be an award for the best submission, as judged by the program committee, either written solely by students or where the major contribution was made by students. An author is considered as a student if, at the time of submission, she/he is enrolled in a program at a university or institution leading to a doctoral/master’s/bachelor’s degree.
 
The program committee reserves the right to give both awards to the same paper, not to give an award, or to split an award among several papers. Papers authored or co-authored by program committee members are not eligible for an award.