Sap Se

Bojana Bislimovska

Gunes Aluc

Mohammed Abouzour

The present disclosure provides techniques and solutions for determining whether a particular value is in a dataset using summary information. A sorted set of unique values is received. The sorted set of unique values includes gaps between at least certain values. The gaps are determined, and the set of unique values is represented as a gap filter. The gap filter includes a starting value of the set of unique values, a set of gap lengths, and identifiers indicating a number of unique values between respective gaps. The gap filter serves as summary information that can be used to determine whether a value be present in the dataset. In at least some cases, the use of the summary information may provide false positive results. The representation of the gap filter can be modified to improve its compressibility, but may increase the number of false positives produced by the gap filter.

Dataset summary metadata providing improved query performance

The present disclosure provides techniques and solutions for sorting data. In a particular implementation, a sorting technique is provided that places values in a sorted order by adding an offset value to values that are not in a sorted order. The resulting sorted set of values is not truly sorted, in that the set of modified values is sorted, but the underlying data itself is not sorted. In another implementation, a sorting technique can use multiple streams or sets. When an out of order element is encountered, it can be added to a new stream, if such a stream is available. The sorting techniques can be used for a variety of purposes, including provided sorted data for use in generating summary data, or for providing sorted data to be used in determining an intersection between two datasets.

Efficient sorting techniques facilitating the creation and use of dataset summary metadata

A system includes reception of a request to fetch a first dataset, the request including a first identifier associated with the first dataset, determination, in response to the request, of a first signature associated with the first dataset based on the first identifier and on respective identifiers of one or more datasets fetched consecutively with the first dataset, and determination, based on the determined first signature, of whether to update a first link associating a second dataset with the first dataset, the link indicating to prefetch the first dataset in response to a request to fetch the second dataset.

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Waterloo, Canada

Bojana Bislimovska