Abstract: A database server that manages a database retrieves metadata that is stored, within the database, in association with a procedure that is stored in the database. Based on the metadata, a Web service definition is automatically constructed to describe the procedure as a Web service. The WSDL definition can be referenced to construct SOAP messages with the appropriate arguments and in the appropriate format which, when received, are converted to a suitable format for invoking execution of the procedure by the database server.

Abstract: In one embodiment, a database server receives a request from a spreadsheet application to open a file with spreadsheet data. The spreadsheet data is stored in one or more relational tables in one or more relational databases that are managed by the database server. In response to the request, the database server generates the file, where generating the file comprises retrieving the spreadsheet data from an XML view that is defined by an XQuery query. When executed, the XQuery query returns the spreadsheet data in an XML spreadsheet format that is understood by the spreadsheet application. The database server provides the generated file with the spreadsheet data directly to the spreadsheet application, where the spreadsheet data as retrieved from the XML view is formatted according to the XML spreadsheet format.

Abstract: Techniques for effectively and efficiently supporting XML sequence type and XQuery sequence natively in a SQL system are described. According to one aspect, SQL functions that correctly handle XML sequences are provided. Thus, XML sequences are handled effectively. According to another aspect, rules for simplifying an abstract syntax tree (AST) that represents one or more such SQL functions are provided. For each such SQL function that is represented in an AST that represents a SQL query, one or more rules that are relevant to that SQL function are determined. Relevant rules are applied to the representation of the SQL function within the AST. Through the application of the rules to the representations of the SQL functions within the AST, the AST is modified in a manner that simplifies the AST prior to the evaluation of the AST at query execution time. Thus, XML sequences are handled efficiently.

Abstract: An XQuery access API is described, for providing access to XML data from a data source, using the XQuery language. A requestor can request, from a server, performance of an operation on XML data, wherein request messages and response messages conform to the Simple Object Access Protocol (SOAP). Request and response messages can be transmitted using Hypertext Transfer Protocol (HTTP) or Hypertext Transfer Protocol over Secure Socket Layer (HTTPS). The format of the request and response messages is specified in a definition of a Web service, where the definition conforms to the Web Service Description Language (WSDL).

Abstract: Techniques are described herein for automatically generating multiple interrelated database tables to store XML data, while ensuring that each such table has no more than the maximum DBMS-allowed number of columns. In response to the registration of an XML schema with a database server, the server determines whether any of the elements specified in the XML schema are complex elements that have more than a threshold number of descendant elements. If a complex element has more than the threshold number of descendant elements, then the server automatically generates one or more separate “out-of-line” database tables for storing at least some of those descendant elements, so that the table created to store the complex element will have no more than the permitted number of columns. Each of the out-of-line database tables is similarly generated so as to have no more than the permitted number of columns.

Abstract: An XQuery access API is described, for providing access to XML data from a data source, using the XQuery language. A requestor can request, from a server, performance of an operation on XML data, wherein request messages and response messages conform to the Simple Object Access Protocol (SOAP). Request and response messages can be transmitted using Hypertext Transfer Protocol (HTTP) or Hypertext Transfer Protocol over Secure Socket Layer (HTTPS). The format of the request and response messages is specified in a definition of a Web service, where the definition conforms to the Web Service Description Language (WSDL).

Abstract: An XQuery access API is described, for providing access to XML data from a data source, using the XQuery language. A requestor can request, from a server, performance of an operation on XML data, wherein request messages and response messages conform to the Simple Object Access Protocol (SOAP). Request and response messages can be transmitted using Hypertext Transfer Protocol (HTTP) or Hypertext Transfer Protocol over Secure Socket Layer (HTTPS). The format of the request and response messages is specified in a definition of a Web service, where the definition conforms to the Web Service Description Language (WSDL).

Abstract: Disclosed is a method and mechanism for processing expressions and operator trees. An approach is particularly useful to optimize processing of XML statements with respect to SQL operators. A top-down processing approach can be taken to directly output data from operators to a data stream. In addition, multiple processing approaches can be taken within a single expression tree, with some operators processed using the top-down approach and other operators processed with the bottom-up approach. Even data that can not be streamed is copied fewer times using this approach, intermediate values from bottom-up processing may still be streamed if it is used by an operator that is eligible for top-down processing.

Abstract: Techniques for processing reference-based SQL/XML operators are provided. Instead of extracting copies of one or more nodes from XML data, a reference-based operator returns a reference to a node. Such a reference is used to determine, for example, whether the corresponding node comes logical before, after, or is the same as another node. An SQL/XML query that includes a reference-based operator may be the original query, or may be generated (e.g., rewritten) from a non-SQL/XML query, such as an XQuery query. One or more physical rewrites may be performed on the SQL/XML query, depending on how the XML data is stored and/or whether an XML index exists for the XML data.

Abstract: Efficiently replicating XML data among databases includes techniques for (a) replicating XML data involved with an insert operation; (b) replicating XML data involved with an update operation; (c) leveraging existing relational replication techniques for XML data stored in shredded form using object-relational constructs; and (d) replicating XQuery Data Model sequences. Each technique reduces the amount of information that would otherwise need to be transmitted over a network for XML data replication purposes.

Abstract: A method for representing XML information is provided. A serialized image of XML information is generated. The serialized image comprises a collection of one or more serialized data values, where each particular serialized data value in the collection includes data associated with a particular serialized data value type of a plurality of serialized data value types. The serialized image may also comprise a first field that includes a first value, which indicates that the serialized image includes the collection of one or more serialized data values. In some embodiments, the method is performed at a database system that supports a native XML data type, wherein the XML information is one or more instances of the native XML data type.

Abstract: Instances of complex types are logically replicated. In general, the logical replication of complex types involves converting a complex type instance from its storage format into a logical representation written in a markup language, like XML. The logical representation is then propagated to a destination (or destinations), which converts the logical representation to a storage format used at the destination for that complex type.

Abstract: A method for optimizing queries is described. A query, which includes a first expression for determining whether each of a set of values evaluates to NULL or NOT NULL, is received. At compile-time, a first representation of the query is generated, where the first representation indicates that the query is to be performed based on the first expression. Based on the first expression, a second expression is determined. The second expression is such that the first expression would evaluate to any NOT NULL value if and only if the second expression would evaluate to any NOT NULL value. The second expression, when evaluated, is much more computationally efficient compared with the evaluation of the first expression. Based on the first representation, a second representation of the query is generated, where the second representation indicates that the query is to be performed based on the second expression. Thereafter, the query is executed based on the second representation.

Abstract: A method for processing queries is provided. A first representation of a query is generated, where the query includes a certain operator that is to be performed based on an XPath expression that is expandable into multiple location paths. The first representation of the query is rewritten into a second representation that corresponds to an equivalent query, where rewriting the first representation includes expanding the XPath expression into the plurality of location paths and, based on the certain operator, including a plurality of operators in the second representation, where the plurality of operators include: a first set of operators that is to be performed based on each of the plurality of location paths, and a second set of operators that is to be performed based on data returned from at least one operator included in the first set of operators. The query may thereafter be executed based on the second representation.

Abstract: Optimization is provided for database statements involving XML data, e.g., XPath and XQuery, which operate over views that use aggregate set operators, e.g., UNION ALL. As part of a “view merge” stage of query transformation, the query that operates over the view is merged with a query that defines the view. One or more expressions (e.g., operators, predicates, virtual table constructs) from the query that operates over the view are then “pushed down” to operate on the individual underlying XML data constructs. “Branch elimination” is performed based on the structure of the view and the query acting over the view, based on which it is possible to determine whether any of the sub-queries, if executed, would result in the return of zero rows. If so, then such branches are eliminated from the transformed query, leaving a reduced set of data containers on which to execute the query.

Abstract: A universal format is used to create a type representation of XMLType instances that are generated in various ways from various sources. An XMLType Type Tree is represented as a hierarchy of nodes, including leaf item node, composite item node, operator node, aggregate node, referred to herein as an XMLType Type Tree. An XMLType Type Tree serves as a digest of the type structure of XMLType, no matter the source of the XMLType instance or its manner of its generation and it creates one uniform abstraction of the type structure of XMLType for the data-typing analysis of XPath and XQuery during query compile time.

Abstract: Techniques are described herein for automatically generating multiple interrelated database tables to store XML data, while ensuring that each such table has no more than the maximum DBMS-allowed number of columns. In response to the registration of an XML schema with a database server, the server determines whether any of the elements specified in the XML schema are complex elements that have more than a threshold number of descendant elements. If a complex element has more than the threshold number of descendant elements, then the server automatically generates one or more separate “out-of-line” database tables for storing at least some of those descendant elements, so that the table created to store the complex element will have no more than the permitted number of columns. Each of the out-of-line database tables is similarly generated so as to have no more than the permitted number of columns.

Abstract: In one embodiment, a database server receives a request from a spreadsheet application to open a file with spreadsheet data. The spreadsheet data is stored in one or more relational tables in one or more relational databases that are managed by the database server. In response to the request, the database server generates the file, where generating the file comprises retrieving the spreadsheet data from an XML view that is defined by an XQuery query. When executed, the XQuery query returns the spreadsheet data in an XML spreadsheet format that is understood by the spreadsheet application. The database server provides the generated file with the spreadsheet data directly to the spreadsheet application, where the spreadsheet data as retrieved from the XML view is formatted according to the XML spreadsheet format.

Abstract: Techniques for processing reference-based SQL/XML operators are provided. Instead of extracting copies of one or more nodes from XML data, a reference-based operator returns a reference to a node. Such a reference is used to determine, for example, whether the corresponding node comes logical before, after, or is the same as another node. An SQL/XML query that includes a reference-based operator may be the original query, or may be generated (e.g., rewritten) from a non-SQL/XML query, such as an XQuery query. One or more physical rewrites may be performed on the SQL/XML query, depending on how the XML data is stored and/or whether an XML index exists for the XML data.

Abstract: To associate XML data objects (“child objects”), stored in rows of relational or object-relational tables, with the appropriate XML data objects (“parent objects”) from which the child objects descend, tables that contain child objects (“out-of-line” tables) are constructed with an additional column. In one embodiment, this column stores values that identify the root objects, in the appropriate table, from which the respective child objects descend. Hence, the root object from which any given object descends is traceable by following the respective value back to the corresponding root object. In one embodiment, this column stores values that identify the complete XML hierarchical path, through multiple tables, back to the root object from which the respective child objects descend. Consequently, XML query language queries against XML documents stored in such tables can be rewritten as SQL queries against the data in the tables, even in the presence of cyclic constructs.