Abstract: Embodiments of the invention relate to a multi-level database compression technique to compress table data objects stored in pages. A compact dictionary structure is encoded that represents frequent values of data at any level of granularity. More than one level of compression is provided, wherein input to a finer level of granularity is an output of a coarser level of granularity. Based upon the encoded dictionary structure, a compression technique is applied to a stored page to compress each row on the page. Similarly, a de-compression technique may be applied to decompress the compressed data, utilizing the same dictionary structures at each level of granularity.

Abstract: According to one embodiment of the present invention, a method for processing join predicates in full-text indexes is provided. The method includes evaluating local predicates of an outer full text index to generate a first posting list of documents. For each document in the first posting list, the value of a join attribute is determined and an inner full text index is probed to obtain a second posting list of documents containing one of the join attributes determined for each document. Local predicates of an inner full text index are evaluated to generate a third posting list of documents, and the second posting list is merged with the third posting list to generate a merge list of documents. Documents in the first posting list may be paired up with documents in the merge list.

Abstract: Embodiments of the invention relate to a multi-level database compression technique to compress table data objects stored in pages. A compact dictionary structure is encoded that represents frequent values of data at any level of granularity. More than one level of compression is provided, wherein input to a finer level of granularity is an output of a coarser level of granularity. Based upon the encoded dictionary structure, a compression technique is applied to a stored page to compress each row on the page. Similarly, a de-compression technique may be applied to decompress the compressed data, utilizing the same dictionary structures at each level of granularity.

Abstract: According to one embodiment of the present invention, a method for processing join predicates in full-text indexes is provided. The method includes evaluating local predicates of an outer full text index to generate a first posting list of documents. For each document in the first posting list, the value of a join attribute is determined and an inner full text index is probed to obtain a second posting list of documents containing one of the join attributes determined for each document. Local predicates of an inner full text index are evaluated to generate a third posting list of documents, and the second posting list is merged with the third posting list to generate a merge list of documents. Documents in the first posting list may be paired up with documents in the merge list.

Abstract: A method is disclosed for executing a predetermined query plan, the method comprising: executing a portion of the query plan; providing a reordered query plan; comparing ranking metrics for the query plans; and executing the query plan having the lower ranking metric.

Abstract: A method is disclosed for executing a predetermined query plan, the method comprising: executing a portion of the query plan; providing a reordered query plan; comparing ranking metrics for the query plans; and executing the query plan having the lower ranking metric.

Abstract: A method and apparatus are disclosed for querying streaming extensible markup language (XML) data comprising: routing elements to query nodes, the elements derived from the streaming extensible markup language data; filtering out elements not conforming to one or more predetermined path query patterns; adding remaining elements to one or more dynamic element lists; accessing a decision table to select and return a query node related to a cursor element from the dynamic element lists; and processing the cursor element related to the returned query node to produce an extracted tuple output.

Abstract: A method and apparatus are disclosed for querying streaming extensible markup language (XML) data comprising: routing elements to query nodes, the elements derived from the streaming extensible markup language data; filtering out elements not conforming to one or more predetermined path query patterns; adding remaining elements to one or more dynamic element lists; accessing a decision table to select and return a query node related to a cursor element from the dynamic element lists; and processing the cursor element related to the returned query node to produce an extracted tuple output.