Many data base management systems’ query optimizers choose at most one index for accessing the records of a table in a given query, even though many indexes may exist on the table. In spite of the fact that there are some systems which use multiple indexes, very little has been published about the concurrency control or query optimization implications (e.g., deciding how many indexes to use) of...

In data warehousing applications, the ability to efficiently delete large chunks of data from a table is very important. This feature is also known as Rollout or Bulk Deletes. Rollout is generally carried out periodically and is often done on more than one dimension or attribute. The ability to efficiently handle the updates of RID indexes while doing Rollouts is a well known problem for databa...

We aim to provide table answers to keyword queries using a knowledge base. For queries referring to multiple entities, like “Washington cities population” and “Mel Gibson movies”, it is better to represent each relevant answer as a table which aggregates a set of entities or joins of entities within the same table scheme or pattern. In this paper, we study how to find highly relevant patterns i...

Page 3, Table 2, 'Renal function indexes at different dates after admission': The cell entry in column 2, detailing the patient's urea concentration (μmol/L) on Day 1.

the present research has been carried out to study the structure of indexing language databases of irandoc. three databases have been selected as a sample: iranian dissertation abstracts. directory of scientific meetings held in iran. current research in iranian universities and research centers. some descriptors have been selected as a sample for study. to analyze the descriptors checklist was...

Machine-learning techniques, properly combined with data structures, have resulted in Learned Static Indexes, innovative and powerful tools that speed up Binary Searches the use of additional space respect to table being searched into. Such is devoted machine-learning models. Although their infancy, these are methodologically practically important, due pervasiveness Sorted Table Search procedur...

Bitmap indexes must be compressed to reduce input/output costs and minimize CPU usage. To accelerate logical operations (AND, OR, XOR) over bitmaps, we use techniques based on run-length encoding (RLE), such as Word-Aligned Hybrid (WAH) compression. These techniques are sensitive to the order of the rows: a simple lexicographical sort can divide the index size by 9 and make indexes several time...