as xml is increasingly being used in data intensive applications, the number and the size of xml databases expand rapidly and thus efficiently managing xml data and processing xml queries have become the focus of database researchers 隨著xml數(shù)據(jù)在網(wǎng)絡(luò)上激增,xml數(shù)據(jù)庫(kù)的數(shù)量及體積快速膨脹,如何高效地管理和查詢這些xml數(shù)據(jù)已成為一個(gè)值得研究的重要課題。