Figure 5 - available via license: Creative Commons Attribution 2.0 Generic
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An example of the parse tree building. The parse tree is constructed from the normalized regular expression, STAR nodes converting, and ALL nodes merging.
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As the Resource Description Framework (RDF) data model is widely used for modeling and sharing a lot of online bioinformatics resources such as Uniprot (dev.isb-sib.ch/projects/uniprot-rdf) or Bio2RDF (bio2rdf.org), SPARQL - a W3C recommendation query for RDF databases - has become an important query language for querying the bioinformatics knowled...
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Context 1
... the second step of the algorithm, we can construct a parse tree using this normalized regular expression. The example of the parse tree for the normalized regu- lar expression is represented in Figure 5(a). The leaf nodes in the parse tree contain grams that are separated by OR, AND, or STAR operators. ...
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... is because STAR nodes can be repre- sented as all combinations of their descendant nodes, and the number of possible grams for the STAR nodes is infinite. The shaded nodes in Figure 5(b) are the converted ones. After the conversion, the nodes that have the ALL nodes as their children are merged into AND or OR nodes with their children. ...
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... IDXAND or an IDXOR are logical AND or OR operators between the two sets of the triple IDs that come from its child operators. For example, Figure 6(a) represents the converted parse tree in Figure 5. The AND and OR nodes are converted into the IDXSCAN and IDXOR operators, and each leaf node g is converted into the IDXSCAN(g) operator. ...
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Citations
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