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XMLtoRelational Data Mapping Algorithms OXInsert and SDM
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XML-to-Relational Data Mapping Algorithms OXInsert and SDM. Speaker: Artem Chebotko ... studies showed that these algorithms are efficient and well scalable ... – PowerPoint PPT presentation
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Title: XMLtoRelational Data Mapping Algorithms OXInsert and SDM
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XML-to-Relational Data Mapping Algorithms
OXInsert and SDM
- Speaker Artem Chebotko
- Email artem_at_wayne.edu
- Wayne State University
- Joint work with Mustafa Atay, Shiyong Lu and
Farshad Fotouhi
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Introduction
- XML has emerged as the standard for representing
and exchanging data on the World Wide Web. - The increasing amount of XML documents requires
the need to store and query XML documents
efficiently.
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Current approaches of storing and querying XML
documents
- Native XML repositories, e.g., Software AGs
Tamino, eXcelons XIS. - XML-enabled commercial database systems such as
SQL Server, Oracle, and DB2 - Using RDBMS/ODBMS to store and query XML
documents.
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Issues of the relational approach
- Schema Mapping
- XML data model needs to be mapped into the
relational model - Data Mapping
- XML documents need to be shredded and composed
into tuples to be inserted into the relational
database - Query Mapping
- XML queries need to be translated into SQL
queries - Reverse Data Mapping
- Query results need to be tagged to XML format.
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Our contributions
- We propose an efficient DOM-based linear data
mapping algorithm, OXInsert, which shreds and
composes input XML documents into relational
tuples and inserts them into the relational
database according to the schema generated by
ODTDMap. - We propose an efficient and linear SAX-based data
mapping algorithm, SDM, which shreds and composes
ordered XML documents into relational tuples and
inserts them into the relational database
according to the schema generated by ODTDMap.
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Outline of the talk
- Main issues for data mapping
- Data mapping algorithm OXInsert
- Data mapping algorithm SDM
- Complete example
- Conclusions and future work
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Main issues for data mapping
- Varying document structure. XML documents have
varying structures due to the optional occurrence
operators ?', ', and choice operator ' used
in the underlying DTD, unlike relational tables
which always have a fixed structure. - Scalability.
- Preserve document order.
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XML Tree
- Definition 4.1 (XML Tree) We model an XML
document D as an XML element tree (XML Tree) T,
in which nodes represent XML elements and edges
represent parent-child relationships between XML
elements. The XML Tree T is an ordered tree and
its nodes can have attributes and values
associated with them. The root of XML Tree T is
denoted by T.root.
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XML Tree (cont)
- For each element node e in T, we use the
following notations
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OXInsert time complexity
- Lemma 4.2 Each non-inlinable element e in XML
Tree T is enqueued into Queue q exactly once, and
q only contains non-inlinable elements. - Lemma 4.3 Each XML element e, except the root
element in XML Tree T is enqueued into queue r
exactly once. - Theorem 4.4 (Time Complexity) The time complexity
of algorithm OXInsert is O(n), where DTD Graph G,
Relational Schema R and Schema Mapping s are
fixed and n is the total number of XML elements
and attribute values in XML Tree T.
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SDM time complexity
- Theorem 4.6 (Time complexity) The time complexity
of algorithm SDM is O(n) where n is the number of
elements and attribute values in the input XML
document.
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A complete example
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XML Tree for xbib.xml
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Tables for xbib.xml
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Conclusions
- We identified several challenging issues for the
data mapping problem and proposed two linear data
mapping algorithms, OXInsert and SDM, based on
two well-known XML parsers DOM and SAX,
respectively. - We compared their performance. Experimental
studies showed that these algorithms are
efficient and well scalable with respect to the
size of input documents.
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Future work
- Considering semantic integrity constraints during
data mapping needs to be investigated
