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| |
| Data XML and Node Types |
| |
| XML is used as the data source for XQuery and must be parsed into Hyracks data. Each |
| node type defined in XPath and XQuery can be mapped into pointable defined in Apache |
| VXQuery\x99. |
| |
| * XPath Node Types |
| |
| *--------------------------------+----------------------+---------------+ |
| | <<Data Type>> | <<Pointable Name>> | <<Data Size>> | |
| *--------------------------------+----------------------+---------------: |
| | Attribute Nodes | {{{https://git-wip-us.apache.org/repos/asf?p=vxquery.git;a=blob;f=vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/nodes/AttributeNodePointable.java}AttributeNodePointable}} | 1 + length | |
| *--------------------------------+----------------------+---------------: |
| | Document Nodes | {{{https://git-wip-us.apache.org/repos/asf?p=vxquery.git;a=blob;f=vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/nodes/DocumentNodePointable.java}DocumentNodePointable}} | 1 + length | |
| *--------------------------------+----------------------+---------------: |
| | Element Nodes | {{{https://git-wip-us.apache.org/repos/asf?p=vxquery.git;a=blob;f=vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/nodes/ElementNodePointable.java}ElementNodePointable}} | 1 + length | |
| *--------------------------------+----------------------+---------------: |
| | Node Tree Nodes | {{{https://git-wip-us.apache.org/repos/asf?p=vxquery.git;a=blob;f=vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/nodes/NodeTreePointable.java}NodeTreePointable}} | 1 + length | |
| *--------------------------------+----------------------+---------------: |
| | Processing Instruction Nodes | {{{https://git-wip-us.apache.org/repos/asf?p=vxquery.git;a=blob;f=vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/nodes/PINodePointable.java}PINodePointable}} | 1 + length | |
| *--------------------------------+----------------------+---------------: |
| | Comment Nodes | {{{https://git-wip-us.apache.org/repos/asf?p=vxquery.git;a=blob;f=vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/nodes/TextOrCommentNodePointable.java}TextOrCommentNodePointable}} | 1 + length | |
| *--------------------------------+----------------------+---------------: |
| | Text Nodes | {{{https://git-wip-us.apache.org/repos/asf?p=vxquery.git;a=blob;f=vxquery-core/src/main/java/org/apache/vxquery/datamodel/accessors/nodes/TextOrCommentNodePointable.java}TextOrCommentNodePointable}} | 1 + length | |
| *--------------------------------+----------------------+---------------: |
| |
| |
| * XML Mapping |
| |
| The XML mapping to Hyracks pointables is fairly straight forward. The following example |
| shows how each node is mapped and saved into a byte array used by Hyracks. |
| |
| ** Example XML File |
| |
| The example XML file comes from W3School XQuery tutorial. |
| |
| ---------------------------------------- |
| <?xml version="1.0" encoding="ISO-8859-1"?> |
| <!-- Edited by XMLSpyÆ --> |
| <bookstore> |
| |
| <book category="COOKING"> |
| <title lang="en">Everyday Italian</title> |
| <author>Giada De Laurentiis</author> |
| <year>2005</year> |
| <price>30.00</price> |
| </book> |
| |
| <book category="CHILDREN"> |
| <title lang="en">Harry Potter</title> |
| <author>J K. Rowling</author> |
| <year>2005</year> |
| <price>29.99</price> |
| </book> |
| |
| <book category="WEB"> |
| <title lang="en">XQuery Kick Start</title> |
| <author>James McGovern</author> |
| <author>Per Bothner</author> |
| <author>Kurt Cagle</author> |
| <author>James Linn</author> |
| <author>Vaidyanathan Nagarajan</author> |
| <year>2003</year> |
| <price>49.99</price> |
| </book> |
| |
| <book category="WEB"> |
| <title lang="en">Learning XML</title> |
| <author>Erik T. Ray</author> |
| <year>2003</year> |
| <price>39.95</price> |
| </book> |
| |
| </bookstore> |
| ---------------------------------------- |
| |
| ** Example Hyracks Mapping |
| |
| The mapping is explained through using some short hand for the above example XML file. |
| Realize the direct bytes will not be explained although the pointable names are used for |
| each piece of information. |
| |
| ---------------------------------------- |
| NodeTree { |
| DocumentNode {bookstore} |
| sequence (children) { |
| ElementNode {book} |
| sequence (attributes) { |
| AttributeNode {category} |
| } |
| sequence (children) { |
| ElementNode {title:Everyday Italian} |
| sequence (attributes) { |
| AttributeNode {lang} |
| } |
| ElementNode {author} |
| ElementNode {year} |
| ElementNode {price} |
| } |
| ElementNode {book} |
| sequence (attributes) { |
| AttributeNode {category} |
| } |
| sequence (children) { |
| ElementNode {title:Harry Potter} |
| sequence (attributes) { |
| AttributeNode {lang} |
| } |
| ElementNode {author} |
| ElementNode {year} |
| ElementNode {price} |
| } |
| ElementNode {book} |
| sequence (attributes) { |
| AttributeNode {category} |
| } |
| sequence (children) { |
| ElementNode {title:XQuery Kick Start} |
| sequence (attributes) { |
| AttributeNode {lang} |
| } |
| ElementNode {author} |
| ElementNode {author} |
| ElementNode {author} |
| ElementNode {author} |
| ElementNode {author} |
| ElementNode {year} |
| ElementNode {price} |
| } |
| ElementNode {book} |
| sequence (attributes) { |
| AttributeNode {category} |
| } |
| sequence (children) { |
| ElementNode {title:Learning XML} |
| sequence (attributes) { |
| AttributeNode {lang} |
| } |
| ElementNode {author} |
| ElementNode {year} |
| ElementNode {price} |
| } |
| } |
| } |
| ---------------------------------------- |
| |
| |
