{'fraction_non_alphanumeric': 0.03417721518987342, 'fraction_numerical': 0.013291139240506329, 'mean_word_length': 4.707581227436823, '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}}
Cost-Effective Usage of Bitmap-Indexes in DS-Systems

Index structures are a widely used function of Database Management Systems (DBMS) in order to tune them for a special purpose. Finding the right index configuration is on the one hand extremely complex (NP-problem [6]) and a variation of the Knapsack Problem [9] but on the other hand manual configuration requires high administrative effort by cost-intensive experts (like DBAs). Regarding these facts several approaches like Feedback Control Loop [14] or MAPE from IBM [7] were introduced in current research of self-tuning techniques. These proposals should reduce costs for human resources and bring us closer to more efficient autonomous DBS. Based on these perceptions we analysed the state of the art in the field of Data Warehousing and Online Analytical Processing (OLAP) systems. In this area it is noticeable that bitmap-indexes have often a marginal use in spite of crucial advantages in the given scenarios of DSS. Many case studies are available for the Oracle DBMS which has integrated a support for bitmap-indexes [8]. Instead we could find several approaches, which were based on heuristics of experts and DBAs like Join-Indexes [12, 4]. With the aid of these approaches it is possible to evaluate design tools like Database Tuning Advisor for Microsoft SQL Server 2005 [1, 2] or DB2 Design Advisor [15] and give online advise to tune a DBS, but until now it is not possible to give an online cost estimate for bitmap-indexes. Hence, a self-tuning approach like those for B-trees [3, 11] is not available yet.