Towards the Optimal Secondary Index Organisation and Secondary Index Selection

Recycling Secondary Index Structures

Many database reorganization techniques move tuples in a table from one location to another in a single pass. For example, distributed database systems move or copy tables between sites to optimize data placement. However, such systems typically drop and then rebuild the secondary indices defined over the table being moved. There are two primary reasons for this. First, moving a table invalidat...

A Compressed Text Index on Secondary Memory

We introduce a practical disk-based compressed text index that, when the text is compressible, takes much less space than the suffix array. It provides good I/O times for searching, which in particular improve when the text is compressible. In this aspect our index is unique, as most compressed indexes are slower than their classical counterparts on secondary memory. We analyze our index and sh...

Estimating stability and selection index

LOD-quadtree: A Spatial Index for Secondary-Storage Selective Refinement

Multi-resolution Terrain Model (MTM), which is widely used for visualizing large terrain, is initially designed as a main-memory method. Such an assumption is no longer valid with the rapidly increasing terrain size, which makes the data exchange between main memory and secondary storage the bottle-neck of multi-resolution terrain visualization. In this paper, a novel multi-resolution access me...

A Lempel-Ziv Text Index on Secondary Storage

Full-text searching consists in locating the occurrences of a given pattern P [1..m] in a text T [1..u], both sequences over an alphabet of size σ. In this paper we define a new index for full-text searching on secondary storage, based on the Lempel-Ziv compression algorithm and requiring 8uHk+o(u log σ) bits of space, where Hk denotes the k-th order empirical entropy of T , for any k = o(log σ...