John Yiannis

dblp:91/6437 · DBLP profile ↗
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2ranked-venue papers
1as first author
0since 2021 · last 2007
—ORCID · none

Domains — the database's venue-derived domains; a paper can count in several

Databases, data management, data science and information retrieval · 2 · 1 first-author

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Databases, data mining, and information retrieval
2 papers
Indexing and storage engines · 43% Information retrieval · 29% Query processing and optimization · 29%

Topics — the 4 heaviest of 5, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Indexing and storage engines
data compression
0.112007
Compression techniques for fast external sorting · VLDB J. 2007
Query processing and optimization › sorting
external sorting
0.112007
Compression techniques for fast external sorting · VLDB J. 2007
Indexing and storage engines › data compression
integer compression
0.012002
Compression of inverted indexes for fast query evaluation · SIGIR 2002
Information retrieval › indexing › index compression
inverted index compression
0.012002
Compression of inverted indexes for fast query evaluation · SIGIR 2002

Methods — techniques the papers use, named apart from their topics

external merge sort · 0.1compression · 0.1golomb-rice coding · 0.0byte-aligned codes · 0.0
YearPublicationVenuePosition
2007 Compression techniques for fast external sorting
John Yiannis, Justin Zobel
VLDB J.1
2002 Compression of inverted indexes for fast query evaluation
abstract
Compression reduces both the size of indexes and the time needed to evaluate queries. In this paper, we revisit the compression of inverted lists of document postings that store the position and frequency of indexed terms, considering two approaches to improving retrieval efficiency: better implementation and better choice of integer compression schemes. First, we propose several simple optimisations to well-known integer compression schemes, and show experimentally that these lead to significant reductions in time. Second, we explore the impact of choice of compression scheme on retrieval efficiency.In experiments on large collections of data, we show two surprising results: use of simple byte-aligned codes halves the query evaluation time compared to the most compact Golomb-Rice bitwise compression schemes; and, even when an index fits entirely in memory, byte-aligned codes result in faster query evaluation than does an uncompressed index, emphasising that the cost of transferring data from memory to the CPU cache is less for an appropriately compressed index than for an uncompressed index. Moreover, byte-aligned schemes have only a modest space overhead: the most compact schemes result in indexes that are around 10% of the size of the collection, while a byte-aligned scheme is around 13%. We conclude that fast byte-aligned codes should be used to store integers in inverted lists.
Falk Scholer, Hugh E. Williams, John Yiannis, Justin Zobel
SIGIR3