{'fraction_non_alphanumeric': 0.028824833702882482, 'fraction_numerical': 0.0, 'mean_word_length': 5.457142857142857, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
X-Time: Schema Versioning and Cross-Version Querying in Data Warehouses

In this demo we present X-Time, a prototype for managing schema versioning in relational data warehouses, specifically oriented to support the formulation of cross-version queries, i.e., queries whose temporal horizon spans multiple versions. The key issue to increase querying flexibility is the introduction of augmented schemata that properly extend previous schema versions.