The Database Principles Column of SIGMOD Record publishes surveys of recent results that appear in database theory conferences (such as ACM PODS or ICDT) in a form suitable for a larger audience.
Leonid Libkin edited the column since its inception in 1999 until June 2011, then the column was edited by Pablo Barcelo (June 2011 - December 2015), Frank Neven(December 2015 - September 2019), and Dan Olteanu (September 2019 - December 2023).
Some of the best database theoreticians (and not only database theoreticians) contributed  papers on many different aspects of databases. All of the papers published in the column can be found below and also here.

Serge Abiteboul
  On views and XML (pdf)

Guozhu Dong, Juanwen Su
    Incremental Maintenance of Recursive Views Using Relational Calculus/SQL (ps)

Jan Van den Bussche
    Constraint Databases: A Tutorial Introduction (pdf)

Alon Halevy
    Theory of Answering Queries Using Views (pdf) 

Peter Buneman, Wenfei Fan, Jerome Simeon, Scott Weinstein
    Constraints for Semi-structured Data and XML (ps)

Luca Cardelli
    Describing Semistructured Data (pdf)

Dan Suciu
    The XML Typechecking Problem (ps)

Ronald Fagin
    Combining Fuzzy Information: an Overview (ps)

Frank Neven
    Automata theory for XML researchers (pdf)

Martin Grohe
    Parameterized Complexity for the Database Theorist (pdf)

Victor Vianu
    From Codd to XML (ps)

Diego Calvanese, Giuseppe De Giacomo, Maurizio Lenzerini, Moshe Vardi
    Regular path queries (pdf)

Thomas Schwentick
    XPath Query Containment (pdf)

Georg Gottlob, Christoph Koch
    Logic-based Web Information Extraction (pdf)

Sara Cohen
     Containment of Aggregate Queries (pdf)

Rick Hull, Jianwen Su
     Tools for Composite Web Services: A Short Overview (pdf)

Francesco Scarcello
     Query Answering Exploiting Structural Properties (pdf)

Alin Deutsch, Lucian Popa, Val Tannen
     Query Reformulation with Constraints (pdf)

Leopoldo Bertossi
     Consistent Query Answering in Databases (pdf)

Marcelo Arenas
     Normalization Theory for XML (pdf)

Luc Segoufin
     Static Analysis of XML Processing with Data Values (pdf)

Wim Martens,   Frank Neven,   Thomas Schwentick
     Simple off the shelf abstractions for XML schema (pdf)

Maarten Marx, Balder ten Cate
     Navigational XPath: calculus and algebra (pdf)

Christoph Koch
     On Query Algebras for Probabilistic Databases (pdf)

Benny Kimelfeld, Yehoshua Sagiv
     Modeling and Querying Probabilistic XML Data (pdf)

Pablo Barcelo
     Logical Foundations of Relational Data Exchange (pdf)

Nicole Schweikardt
     Machine Models for Query Processing (pdf)

Marcelo Arenas, Jorge Perez, Juan Reutter, Cristian Riveros
     Composition and Inversion of Schema Mappings (pdf)

Daniel Deutsch, Tova Milo
     On Models and Query Languages for Probabilistic Processes (pdf)

Andrea Cali, Georg Gottlob, Thomas Lukasiewicz, Andreas Pieris
     A Logical Toolbox for Ontological Reasoning (pdf)

Peter Wood
     Query Languages for Graph Databases (pdf)

Mikolaj Bojanczyk
     Algorithms for Regular Languages that Use Algebra (pdf)

Grigoris Karvounarakis, Todd J. Green
     Semiring-Annotated Data: Queries and Provenance Algebras (pdf)

Marcelo Arenas, Claudio Gutierrez, Daniel Miranker, Jorge Perez, Juan Sequeda
     Querying Semantic Data on the Web (pdf)

Graham Cormode
     The Continuous Distributed Monitoring Model (pdf)

Jan Chomicki, Paolo Ciaccia, Niccolo Meneghetti
     Skyline Queries, Front and Back (pdf)

Hung Q. Ngo, Christopher Re, Atri Rudra
     Skew Strikes Back: New Developments in the Theory of Join Algorithms (pdf)

Andrew Mcgregor.
     Graph Streams Algorithms: A Survey (pdf)

Tom Ameloot
     Declarative Networking: Recent Theoretical Work on Coordination, Correctness, and Declarative Semantics (pdf)

Alin Deutsch, Rick Hull, Victor Vianu
     Automatic Verification of Database-Centric Systems (pdf)

Yael Amsterdamer, Tova Milo
     Foundations of Crowd Data Sourcing (pdf)

Luc Segoufin
     Constant Delay Enumeration for Conjunctive Queries (pdf) 

Wenfei Fan
     Data Quality: From Theory to Practice (pdf)

Ron Fagin, Benny Kimelfeld, Frederick Reiss, Stijn Vansummeren
     A Relational Framework for Information Extraction (pdf)

Dan Olteanu, Maximilian Schleich
     Factorized Databases (pdf)

Serge Abiteboul, Marcelo Arenas, Pablo Barceló, Meghyn Bienvenu, Diego Calvanese, Claire David, Richard Hull, Eyke Hüllermeier, Benny Kimelfeld, Leonid Libkin, Wim Martens, Tova Milo, Filip Murlak, Frank Neven, Magdalena Ortiz, Thomas Schwentick, Julia Stoyanovich, Jianwen Su, Dan Suciu, Victor Vianu, Ke Yi
      Research Directions for Principles of Data Management (Abridged) (pdf)

Paraschos Koutris, Dan Suciu
     A Guide to Formal Analysis of Join Processing in Massively Parallel Systems (pdf)

Pablo Barceló, Andreas Pieris, Miguel Romero
    Semantic Optimization in Tractable Classes of Conjunctive Queries (pdf)

Paolo Guagliardo, Leonid Libkin
    Correctness of SQL Queries on Databases with Nulls (pdf)

Pierre Senellart
    Provenance and Probabilities in Relational Databases: From Theory to Practice (pdf)

Michael Benedikt
    Logic-based Perspectives on Query Reformulation over Restricted Interfaces (pdf)

Peter Buneman, Wang-Chiew Tan
    Data Provenance: What next? (pdf)

Angela Bonifati, Stefania Dumbrava
    Graph Queries: From Theory to Practice (pdf)

Jef Wijsen
     Foundations of Query Answering on Inconsistent Databases (pdf)

Saladi Rahul, Yufei Tao
     A Guide to Designing Top-k Indexes (pdf)

Bernardo Cuenca Grau, Ian Horrocks, Mark Kaminski, Egor V. Kostylev, Boris Motik
     Limit Datalog: A Declarative Query Language for Data Analysis (pdf)

Pablo Barceló, Egor V. Kostylev, Mikaël Monet, Jorge Pérez, Juan L. Reutter, Juan-Pablo Silva
     The Expressive Power of Graph Neural Networks as a Query Language (pdf)

Thomas Schwentick, Nils Vortmeier, Thomas Zeume
     Sketches of Dynamic Complexity (pdf)

Xiao Hu, Ke Yi
     Massively Parallel Join Algorithms (pdf)

Johannes Doleschal, Benny Kimelfeld, Wim Martens
     Database Principles and Challenges in Text Analysis (pdf)

Floris Geerts, Thomas Muñoz, Cristian Riveros, Jan Van den Bussche, Domagoj Vrgoc
     Matrix Query Languages (pdf)

Graham Cormode
     Current Trends in Data Summaries (pdf)

Mahmoud Abo Khamis, Hung Q. Ngo, Reinhard Pichler, Dan Suciu, and Yisu Remy Wang
     Datalog in Wonderland (pdf)

Marcelo Arenas, Luis Alberto Croquevielle, Rajesh Jayaram, and Cristian Riveros
     Counting the Answers to a Query (pdf)

Bas Ketsman, Frank Neven, Christoph Koch, Brecht Vandevoort
     Concurrency Control for Database Theorists (pdf)

Leopoldo Bertossi, Ester Livshits, Benny Kimelfeld, and Mikaël Monet
The Shapley Value in Database Management (pdf)

Wei Dong and Ke Yi
Query Evaluation under Differential Privacy (pdf)

Balder ten Cate, Maurice Funk, Jean Christoph Jung, Carsten Lutz
Fitting Algorithms for Conjunctive Queries (pdf)