Abstract: A method and system are described for generating railing objects that model railing structures, such as fences. According to the method, a railing object is generated along a path within a design layout. As rendered, the railing object includes posts and railings, with the option of using filling material between the posts. According to one variation, the railing object substantially follows an existing path. The railing object may comprise an increasing number of segments to better follow the curvature of the path. Any modification applied to the path is automatically applied to the railing object after the railing object is applied to the path. That is, every railing object component (e.g. post, railing, fencing) will be repositioned along the new position of the path. A mechanism is provided for automatically applying the modifications to the geometric dimensions of a single component instance of a railing object to every instance of that component on the railing object.

Abstract: A method and system for recovering after failure of a first server to which a client was connected for accessing a resource is provided. When it is detected that a connection between the first server and the client has failed, the client is automatically connected with a second server that has access to the resource. After automatically connecting the client, the client accesses the resource through the second server. The client stores information about the state of the session with the first server so that processing can continue where it left off after the client connects with the second server. The client may be pre-connected to the second server prior to the failure of the first server to reduce the latency caused by switching in response to a failure. The second server may be configured to pre-parse the commands that the client issues to the first server to further reduce the latency associated with switching to the second server.

Abstract: A method and apparatus for printing an automatically assembling an electronic document is disclosed. The electronic document comprises first and second sets of pages, in which the first set of pages has a first characteristic and the second set has a second characteristic. Using a parser or based on information embedded in the electronic document, the first and second sets of pages are identified. First and second output devices, that are respectively compatible with the first and second sets of pages, are selected. The sets of pages are routed to the respective output devices, where they are output. Identifying information is also routed to be output with the pages. After the pages are output, a complete document is automatically merged or assembled based on the identifying information. In a preferred embodiment, the electronic document has monochrome or black-and-white pages and color pages. The pages are identified within the document.

Abstract: A method and apparatus are provided for converting a non-versioned schema to a version-enabled schema. The method includes reading a first set of table definitions that belong to the non-versioned schema. A second set of table definitions is generated for the version-enabled schema such that each table definition in the second set of table definitions corresponds to a table definition in the first set of table. Each table definition in the second set of table definitions includes columns that correspond to the columns of the corresponding table definition in the first set of table definitions and one or more additional columns for storing version information. Multiple versions of a particular object are stored within the table. In response to a request from a user to retrieve the particular object, a version of the particular object to present to the user is determined based on a workspace associated with the user.

Abstract: A highly scalable, flexible, and extensible mechanism is provided for authenticating a request from a client. In a preferred embodiment, the invention comprises an authentication engine, an authentication host, a plurality of providers coupled to the host which implement selected authentication schemes, and a machine independent communication mechanism which enables the various components to communicate with each other irregardless of the machine each component resides on. The communication mechanism enables the invention to be distributed, which in turn, makes the invention highly scalable. In operation, the authentication engine receives a request having associated therewith a protect string. The protect string specifies the authentication scheme or schemes that need to be implemented for that request. The authentication engine parses the protect string into one or more provider requests, and sends the requests to the authentication host.

Abstract: A method and apparatus are provided for indexing electronic documents that include one or more visible text portions and one or more non-visible text portions. The method includes the step of identifying an electronic document. Once the electronic document is identified, a set of words is selected from a particular tag type that is associated with one or more non-visible text portions of the electronic document. Each word in the selected set of words is compared with words in the one or more visible text portions of the electronic document. An index word set is then determined for the electronic document based on matches between words in the selected set of words and words in the one or more visible text portions of the electronic document.

Abstract: According to an approach for propagating messages in a distributed computer system, message information is identified that needs to be sent to a destination site. After the message information is identified, the message information is assigned a propagation sequence number that identifies when the message information is sent to the destination site relative to other message information sent from the source site to the destination site. A message that is based on the message information is then transmitted to the destination site. The transmitted message includes the sequence number value and a source ID that identifies the source site as transmitting the message to the destination site. After the message is received at the destination site, the propagation sequence number that was assigned to the message information may be stored in nonvolatile memory at the destination site.

Abstract: A method and apparatus for managing access to resources is provided. When a process requires access to a resource, the process requests a lock on the resource from a lock manager unit that resides on the same node as the process. If a resource object for the resource does not exists, one is created in the lock manager unit, but not on lock manager units on other nodes. Because each lock manager unit does not have to store all resource objects, and resource objects are only created for resources that are actually used, the overhead of the lock management system is significantly reduced. Resources are grouped in recovery domains. When a lock manager unit that supported a recovery domain fails, the recovery domain is marked invalid. All resources in the recovery domain are considered invalid unless it would have been impossible for a failed instance to have held an exclusive lock on the resource. A snapshot of lock information is made before cleanup is performed on invalid resources.

Abstract: A method and apparatus for identifying one or more schemas from which a Structured Query Language (SQL) statement may have been executed is provided. According to the method, to identify schemas from which a database command may have been executed a set of object references that are included in the database command is determined. From the set of object references, one or more ambiguous object references that are contained in the set of object references are identified. A set of one or more schemas that contain objects that correspond to each of the one or more ambiguous object references is then identified.

Abstract: The present invention provides a method and apparatus for partitioning a buffer cache for dynamically mapping data blocks with a particular replacement strategy based on the associated table's access and/or usage patterns. According to the method, a buffer cache in a computer system is managed by dividing the buffer cache into multiple buffer pools. In managing the buffer cache, when a data item is requested, it is first determined whether the requested data item is stored in a buffer within the buffer cache. If the requested data item is not stored in a buffer in the buffer cache, then a particular buffer pool in the buffer cache is dynamically selected for storing the requested data item. Once the particular buffer pool is selected, the requested data item is stored into a buffer in the particular buffer pool.

Abstract: A method and system for reducing overhead associated with recovering after a failure. According to the method, a checkpoint value is maintained that indicates which records of a plurality of records have to be processed after the failure. The plurality of records contain change information that corresponds to a plurality of data blocks. A target checkpoint value is determined based on a desired number of data block reads that will be required during a redo phase of recovery. Changes contained in volatile memory are then written to nonvolatile memory to advance the checkpoint value to at least the target checkpoint value. According to another aspect of the invention, the target checkpoint value is determined using a circular queue of offset buckets. The offset buckets are used to store index values that are associated with buffers in the ordered list. The target checkpoint value is periodically set equal to an index value that is contained in an offset bucket.

Abstract: A method and system for processing multiple-request transactions in a stateless environment is provided. A cartridge execution engine intercepts browser messages directed to a cartridge. The cartridge execution engine determines whether the browser messages are associated with transactions. If it is determined that browser messages are associated with transactions, then the cartridge execution engine sends transaction control messages to a transaction manager. In addition, the cartridge execution engine sends operation messages to the cartridge. The cartridge then performs the operations specified in the operation messages. In response to the transaction control messages from the cartridge execution engine, the transaction manager causes the multiple-request transactions to be either committed or rolled back as an atomic unit of work.

Abstract: A method and system for determining the spacing of objects is described. According to the method, input is received that indicates bounds of at least one dimension of a constraint. A set of supplied parameter values associated with a particular type of grid is also received. A set of generated parameter values for the particular type of grid is then generated based on the set of supplied parameter values and the input indicating bounds of at least one dimension of a constraint. A set of points for spacing objects is generated based on the set of supplied parameter values and said set of generated parameter values. According to one aspect, a set of object information is received that identifies a particular object to be placed on the constraint at locations that are based on the set of points. According to another aspect, the set of object information identifies a bounding box that is associated with the particular object. The bounding box is then used to generate the set of generated parameters.

Abstract: A method and apparatus for removing changes made by a particular transaction is provided. According to one aspect, two or more sets of changes that were made by a particular transaction that can be removed in parallel are identified. A corresponding recovery process is assigned to each of the two or more sets of changes. Using the corresponding recovery process, the changes identified in each of the two or more sets of changes are undone in parallel.

Abstract: A method and system are provided for maintaining a checkpoint value that indicates which records of a plurality of records associated with updates made before a failure have to be processed after the failure. According to one aspect of the invention, an ordered list of buffers is maintained in volatile memory. The ordered list of buffers has a head and a tail. The ordered list of buffers is maintained by writing a record that indicates the update to nonvolatile memory and adding the buffer to the tail of the ordered list whenever an update is made to a data item within a buffer in volatile memory. When a data item contained in a buffer within the ordered list is stored in nonvolatile memory, the buffer can be removed from the ordered list. A checkpoint value that identifies a record associated with a buffer located at the head of the ordered list is written to nonvolatile memory. According to another aspect, after a failure, the record associated with the checkpoint value is identified.

Abstract: A system, method, and computer readable-medium for performing operations associated with browser requests are provided. The system includes a plurality of dispatchers coupled to a plurality of web listeners. Each of the dispatchers receives from a corresponding web listener browser requests received by the corresponding web listener. The system further includes a virtual path manager and a resource manager. The virtual path manager is coupled to the dispatchers through an inter-machine communication mechanism. The virtual path manager indicates to the dispatchers which of a cartridges is associated with the browser requests. The resource manager is coupled to the dispatchers through the inter-machine communication mechanism. The resource manager is configured to assign to each dispatcher of the dispatchers an instance of a cartridge of the cartridges in response to receiving a request for an instance from the dispatcher.

Abstract: A method and system for removing propagation delays between a plurality of database servers that have access to a common database is provided. According to the method, each database server is associated with a logical clock. In response to initiating a commit of a transaction executing on a database server, a commit time for the transaction is determined and broadcast to one or more other database servers. The broadcast is overlapped with a transaction log force. Upon receiving the commit time, the database servers compare the transmitted commit time to the time indicated by their logical clock. If the commit time is greater than the time indicated by their logical clock, the database server sets its logical time to reflect a time that is at least as recent as the time reflected by the transmitted commit time.

Abstract: A method and apparatus are provided for allocating buffer memory for database sort operations. A database parameter is set to determine whether and how direct write buffers are to be allocated for sort operations. If the parameter is set to a first value, then direct write buffers will be used to perform writes to disk. The size and number of direct write buffers to be used will be determined by the values set in other database parameters. If the parameter is set to a second value, then no direct write buffers will be used, and sort operations will write to disk through a buffer cache. If the parameter is set to a third value, direct write buffers will be allocated a portion of the memory available to perform the sort operation. The size and number of direct write buffers will be determined in accordance with database formulae that are designed to optimize sort and data write performance.

Abstract: The present invention provides an effective and highly scalable mechanism for supporting multiple-request operations (including but not limited to transactions) in a stateless environment, such as the web. A server is used to coordinate the overall processing of client requests. The server performs this coordination function in such a way that: (1) state information associated with multiple-request operations is maintained by the clients making the requests; (2) the clients are unaware that they are maintaining operation-specific state information; and (3) the server itself is not required to persistently maintain the state information, thereby remaining stateless.

Abstract: A method and apparatus are provided for passing a client from a first server to which the client was connected for accessing a resource, to a second server for accessing the resource. While executing, the first server ceases to respond to the client. After the client detects that the first server has ceased to respond to the client, the client is automatically connected with the second server that has access to the resource. After automatically connecting the client, the client accesses the resource through the second server. The client stores information about the state of the session with the first server so that processing can continue where it left off after the client connects with the second server. The client may be pre-connected to the second server prior to the failure of the first server to reduce the latency caused by switching in response to a failure.