This two volume set LNCS 7446 and LNCS 7447 constitutes the refereed proceedings of the 23rd International Conference on Database and Expert Systems Applications, DEXA 2012, held in Vienna, Austria, September 3-6, 2012. These papers discuss a range of topics including: database query processing, in particular XML queries;

DIADEM: Domains to Databases.- Stepwise Development of FormalModels forWeb Services Compositions: Modelling and Property Verification.- A Hybrid Approach for General XML Query Processing.- SCOOTER: A Compact and Scalable Dynamic Labeling Scheme for XML Updates.- Reuse the Deleted Labels for Vector Order-Based Dynamic XML Labeling Schemes.-  Towards an Efficient Flash-Based Mid-Tier Cache.- Evacuation Planning of Large Buildings Using Ladders.-  A Write Efficient PCM-Aware Sort.-  Performance Analysis of Algorithms to Reason about XML Keys.-  Finding Top-K Correct XPath Queries of User’s Incorrect XPath Query.- Analyzing Plan Diagrams of XQuery Optimizers.- Spreadsheet Metadata Extraction: A Layout-Based Approach.- Automated Extraction of Semantic Concepts from Semi-structured Data: Supporting Computer-BasedEducation through the Analysis of Lecture Notes.- A Confidence–Weighted Metric for Unsupervised Ontology Population from Web Texts.-  Situation-Aware User’s Interests Prediction for Query Enrichment.- The Effective Relevance Link between a Document and a Query.- Incremental Computation of Skyline Queries with Dynamic Preferences.-  Efficient Discovery of Correlated Patterns in Transactional Databases Using Items’ Support Intervals.- On Checking Executable Conceptual Schema Validity by Testing.- Querying Transaction–Time Databases under Branched Schema Evolution.- Fast Identity Anonymization on Graphs.- Probabilistic Inference of Fine-Grained Data Provenance.- Enhancing Utility and Privacy-Safety via Semi-homogenous Generalization.-Processing XML Twig Pattern Query with Wildcards.- A Direct Approach to Holistic Boolean-Twig Pattern Evaluation.-Full Tree-Based Encoding Technique for Dynamic XML Labeling Schemes.- Top-k Maximal Influential Paths in Network Data.- Learning to Rank from Concept-Drifting Network Data Streams.- Top-k Context-Aware Queries on Streams.- Fast Block-Compressed Inverted Lists.-  Positional Data Organization and Compression in Web Inverted Indexes.-Decreasing Memory Footprints for Better Enterprise Java Application Performance. Knowledge-Driven Syntactic Structuring: The Case of Multidimensional Space of Music Information.- Mining Frequent Itemsets Using Node-Sets of a Prefix-Tree.- MAX-FLMin: An Approach for Mining Maximal Frequent Links and Generating Semantical Structures from Social Networks.-  Sequenced Route Query in Road Network Distance Based on Incremental Euclidean Restriction.- Path-Based Constrained Nearest Neighbor Search in a Road Network.-Efficient Fuzzy Ranking for Keyword Search on Graphs.Stepwise Development of FormalModels forWeb Services Compositions: Modelling and Property Verification.- A Hybrid Approach for General XML Query Processing.- SCOOTER: A Compact and Scalable Dynamic Labeling Scheme for XML Updates.- Reuse the Deleted Labels for Vector Order-Based Dynamic XML Labeling Schemes.-  Towards an Efficient Flash-Based Mid-Tier Cache.- Evacuation Planning of Large Buildings Using Ladders.-  A Write Efficient PCM-Aware Sort.-  Performance Analysis of Algorithms to Reason about XML Keys.-  Finding Top-K Correct XPath Queries of User’s Incorrect XPath Query.- Analyzing Plan Diagrams of XQuery Optimizers.- Spreadsheet Metadata Extraction: A Layout-Based Approach.- Automated Extraction of Semantic Concepts from Semi-structured Data:Supporting Computer-Based Education through the Analysis of Lecture Notes.- A Confidence–Weighted Metric for Unsupervised Ontology Population from Web Texts.-  Situation-Aware User’s Interests Prediction for Query Enrichment.- The Effective Relevance Link between a Document and a Query.- Incremental Computation of Skyline Queries with Dynamic Preferences.-  Efficient Discovery of Correlated Patterns in Transactional Databases Using Items’ Support Intervals.- On Checking Executable Conceptual Schema Validity by Testing.- Querying Transaction–Time Databases under Branched Schema Evolution.- Fast Identity Anonymization on Graphs.- Probabilistic Inference of Fine-Grained Data Provenance.- Enhancing Utility and Privacy-Safety via Semi-homogenous Generalization.-Processing XML Twig Pattern Query with Wildcards.- A Direct Approach to Holistic Boolean-Twig Pattern Evaluation.-Full Tree-Based Encoding Technique for Dynamic XML Labeling Schemes.- Top-k Maximal Influential Paths in Network Data.- Learning to Rank from Concept-Drifting Network Data Streams.- Top-k Context-Aware Queries on Streams.- Fast Block-Compressed Inverted Lists.-  Positional Data Organization and Compression in Web Inverted Indexes.-Decreasing Memory Footprints for Better Enterprise Java Application Performance. Knowledge-Driven Syntactic Structuring: The Case of Multidimensional Space of Music Information.- Mining Frequent Itemsets Using Node-Sets of a Prefix-Tree.- MAX-FLMin: An Approach for Mining Maximal Frequent Links and Generating Semantical Structures from Social Networks.-  Sequenced Route Query in Road Network Distance Based on Incremental Euclidean Restriction.- Path-Based Constrained Nearest Neighbor Search in a Road Network.-Efficient Fuzzy Ranking for Keyword Search on Graphs.

This two volume set LNCS 7446 and LNCS 7447 constitutes the refereed proceedings of the 23rd International Conference on Database and Expert Systems Applications, DEXA 2012, held in Vienna, Austria, September 3-6, 2012. The 49 revised full papers presented together with 37 short papers and 2 keynote talks were carefully reviewed and selected from 179 submissions. These papers discuss a range of topics including: database query processing, in particular XML queries; labelling of XML documents; computational efficiency, data extraction; personalization, preferences, and ranking; security and privacy; database schema evaluation and evolution; semantic Web; privacy and provenance; data mining; data streaming; distributed systems; searching and query answering; structuring, compression and optimization; failure, fault analysis, and uncertainty; predication, extraction, and annotation; ranking and personalisation; database partitioning and performance measurement; recommendation and prediction systems; business processes; social networking.