Abstract: Heterogeneous garbage types are collected by scanning all of the service items to identify all of the service types that are included within the service items, identifying garbage collection components that correspond with the service types, and then collecting garbage for the corresponding target service types by using the corresponding garbage collection components.

Abstract: A database management system stores data for a table using a ledger which comprises journal and summary portions. A query processor of the database identifies a first set of operations to update a document of a table in accordance with an update command. The query processor identifies a second set of operations to update tables or views that are potentially affected by the update to the document. The query processor then causes the first and second sets of operations to be executed as an atomic unit.

Abstract: Some embodiments are directed to accessing a content unit stored in a storage environment that includes a plurality of storage clusters, wherein multiple versions of the content unit are stored on at least two different clusters in the storage environment. The storage environment and/or the requesting entity may identify the at least two storage clusters that store the content unit and select one of clusters as storing a valid version of the content unit.

Abstract: A computer implemented method and system for testing complex data processing systems. A transaction processing testing system may identify test scenarios used to test a software system or application, such as a data processing system, in a modified state. The test scenarios may be based on actual historical data, selected and prioritized using natural language terms, provided to the data processing system and the results of the processing thereof by the data processing system. The testing system may then compare the results of processing one or more particular test scenarios by a modified version of the data processing system against the results of processing the same scenario(s) by the version of the data processing system prior to being modified to determine whether or not there are defects in the modified version. The testing may account for any expected differences between the results due to the modification(s).

Abstract: A method includes performing, by a data structure processor, concurrent read and write operations into a hierarchical data structure that includes a mutable tier including extendible hashing, a hash table, and an immutable tier including a concise hash table (CHT) bitmap. Writers acquire latches on the hierarchical data structure elements that the latches modify. The hierarchical data structure elements are directly accessed by readers without acquiring latches. A modify operation is executed by a writer for one or more levels of the hierarchical data structure. When removed portions of the hierarchical data structure are no longer referenced, tracking is performed by use of a combination of a global state value and a copied local state value.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for data tracing are provided. One of the methods includes: receiving a data backtracking request, the data backtracking request comprising a version identifier of a first data version of a target object; obtaining, from the blockchain, version identifiers of a plurality of second data versions of the target object and a plurality of data blocks in the blockchain, wherein the second data versions comprise an initial data version of the target object, and at least one of the obtained data blocks comprises a version identifier of the initial data version; and determining, based on the version identifier of the initial data version, data content corresponding to the initial data version of the target object.

Abstract: A transaction management service layer monitors a plurality of read and write transactions being executed by the data engines by way of client libraries at each of a plurality of data engines. In addition, the transaction management server layer maintains and coordinates transaction timestamp and sequence numbers that are shared by the plurality of data engines. The transaction management service layer identifies and resolves conflicts among the plurality of transactions. The transaction management service layer is a separate and independent service that is isolated from other components of the plurality of data engines. Related apparatus, systems, techniques and articles are also described.

Abstract: Systems and methods for file replication using file content location identifiers. An example method comprises: receiving, by a processing device, an index node number identifying a first index node associated with a file residing on a first file server, the first index node referencing a physical location of contents of the file; identifying a replica of the file residing on a second file server; assigning the index node number of the first index node to a second index node referencing a physical location of contents of the replica of the file on the second file server; performing, by the processing device, a file system operation by accessing the replica of the file referenced by the index node number.

Abstract: A reader of a set of data accessors that includes readers and writer detects that a particular lock of a first collection of non-global locks associated with a data object of a computing environment is held by another accessor. After checking a blocking indicator, the reader uses a second lock (which is not part of the first collection) to obtain read access to the data object and implements its reads without acquiring the particular lock. Prior to implementing a write on the data object, a writer acquires at least some locks of the first collection, and sets the blocking indicator to prevent readers from using the second lock to obtain read access to the data object.

Abstract: A method, apparatus, and system for join operations of a plurality of relations that are distributed over a plurality of storage locations over a network of computing components.

Abstract: An objective of the present application is to provide a method and device for processing a distributed transaction. Compared with the prior art, in a distributed system, a first device in the present application is a group formed by multiple nodes. The first device acquires a writer lock adding request, sent by an SQL compiler, about a target table of a to-be-processed transaction, and performs writer lock adding processing on the target table on the basis of the writer lock adding request, so as to avoid collision problems in multi-transaction concurrence and to ensure isolation of transactions. If the writer lock adding processing is successful, to-be-processed version information of the target table is sent to the SQL compiler, so as to ensure that the SQL compiler operates a correct version of the target table later.

Abstract: This application belongs to the field of database application technologies, and discloses a data scrubbing method and apparatus. In the method, a server adds a share update exclusive lock to a target table, to prevent a system from performing a data definition language (DDL) operation on the target table. The server then creates a temporary table and a temporary index, copies data from the target table to the temporary table, and generates index information according to the data in the temporary table. Next, the server adds an access exclusive lock to the target table to prevent the system from performing a data manipulation language (DML) operation on the target table. Then data in the target table and the temporary table as well as corresponding index information is exchanged, thereby completing cleaning and reclaiming of disk space.

Abstract: A global and local row count limit associated with a limit query are received by a stop operator of a first execution node among a set of execution nodes that are assigned to process the limit query. Local distributed row count data is generated based on a local row count corresponding to a number of rows output by the first execution node in processing the query. Based on determining the local row count satisfies the local limit, the first execution node buffers rows produced in processing the query. The local distributed row count data is updated based on remote distributed row count data received from a second execution node. A stopping condition is detected based on determining the global limit is satisfied based on updated local distributed row count data and query processing by the first execution node based on detecting the stopping condition.

Abstract: Database recovery can be performed in substantially constant time. From a database transaction log, the state of one or more transactions is identified including those that were active at a time of a crash but not committed. Transactions can be reapplied sequentially starting from the beginning of a last successful checkpoint to the end of the transaction log. Uncommitted user transactions are not undone synchronously, but simply marked as aborted. Subsequently, versions of affected data elements can be reverted back to a prior saved version asynchronously.

Abstract: An exemplary system, method and computer-accessible medium for modifying a design of an integrated circuit(s) (ICs), which can include, for example, modifying a logic gate(s) in the design for a protected input pattern(s), and providing a restoration unit(s) into the design, where the restoration unit(s) can be configured to (i) produce an error-free output(s) when a correct secret key can be applied to the restoration unit(s), and (ii) produce an erroneous output(s) when an incorrect key can be applied to the restoration unit(s); and ensure that the modified design along with the restoration unit produces at least one erroneous output with respect to the original design for only a pre-determined constant number of incorrect keys based on at least one input pattern.

Abstract: A data warehouse storing databases for a plurality of users, including service providers hosting data for other users of the data warehouse may implement a data exchange. A provider of data creates a listing in the exchange including metadata. A consumer browses the metadata and select a listing to add to consumed shares of the consumer. Browsing may be filtered to implement a private exchange. Adding of data may be limited by access controls requiring verification of the consumer's identity. The added data may be filtered to include only data that relates to the consumer. Sharing may be bi-directional such that a request to add a listing for first data of a provider may also reference second data of the consumer such that the first data is added to the consumed shares of the consumer and the second data is added to the consumed shares of the provider.

Abstract: In one embodiment, a set of lock and unlock instructions in a read phase of a computer-readable program is replaced with a first set of tracking instructions, wherein the first set of tracking instructions track a set of locked objects identifying objects that would have been locked by executing the set of lock and unlock instructions. A second set of tracking instructions is inserted into the read phase of the computer-readable program, wherein the second set of tracking instructions track a set of read objects indicating versions of objects that are read. Validation instructions are inserted into the computer-readable program, wherein the validation instructions validate that the versions of objects in the set of read objects have not changed since they were last read and lock the set of locked objects that would have been locked upon completing execution of the set of lock and unlock instructions.

Abstract: Briefly, embodiments disclosed herein relate to managing transactions in a distributed content transaction system.

Abstract: Throughput is preserved in a distributed system while maintaining concurrency by pushing a commit wait period to client commit paths and to future readers. As opposed to servers performing commit waits, the servers assign timestamps, which are used to ensure that causality is preserved. When a server executes a transaction that writes data to a distributed database, the server acquires a user-level lock, and assigns the transaction a timestamp equal to a current time plus an interval corresponding to bounds of uncertainty of clocks in the distributed system. After assigning the timestamp, the server releases the user-level lock. Any client devices, before performing a read of the written data, must wait until the assigned timestamp is in the past.

Abstract: Techniques and mechanisms are provided for migrating data blocks around a cluster during node addition and node deletion. Migration requires no downtime, as a newly added node is immediately operational while the data blocks are being moved. Blockmap files and deduplication dictionaries need not be updated.

Abstract: A system and method for implementing a generation lock for protecting a data structure is provide. The systems and methods synchronizes read and write transactions for a protected data structure in a multitasking environment and provides low latency and improved scalability. For example, a system and method for implementing a generation lock for protecting a data structure may be provided. The generation lock provides an improved mechanism for restricting access to a data structure that is typically read more often than written. Specifically, the generation lock provides a method for reading and writing to a protected data structures that has a low average latency as compared to traditional read/write semaphores. The generation lock also provides a mechanism in which the system is scalable, meaning that the addition of additional processor cores is capable of increasing the performance, e.g., rate of executing requests, of the system, and is not or is not substantially rate limited by a shared resource.

Abstract: A data storage method includes determining a first check value of a first version of a target object, obtaining a second check value of a second version of the target object, creating a data block comprising the first check value and the second check value, and storing the data block in a blockchain, where the data block stored in the blockchain is immutable.

Abstract: A set of nodes are organized into a graph to represent a workflow to enable the dynamic and directed management of that workflow in a decentralized system. Each node maintains a value necessary for execution of the workflow, and includes code to populate that value. A workflow agent manages the population of the values according to an identified dependency structure for the nodes relative to the workflow. As changes are made to the workflow, the workflow agent ensures that values and dependencies of the nodes stay up-to-date. Each node retains historic values, which enables the workflow agent to query several states of the workflow throughout time as changes are made thereto. The dynamic management of the nodes improves the responsiveness of the system to changes, thereby improving computational efficiency.

Abstract: A statement parsing method for a database statement comprises: conducting lexical analysis on a database statement inputted into a database, to obtain an inputted word sequence; looking up a statement similarity table according to the inputted word sequence to determine whether there is an existing word sequence similar to the inputted word sequence in the statement similarity table; if yes, obtaining the parsed data corresponding to the existing word sequence from the statement similarity table; otherwise, parsing the inputted word sequence to obtain parsed data corresponding thereto, and storing the inputted word sequence and the corresponding parsed data in the statement similarity table; and executing the database statement inputted to the database based on the parsed data corresponding to the existing or inputted word sequence. The method can quickly parse a database statement and is favorable for improving the response speed and the working efficiency of a database.

Abstract: A central database maintains values for client publishing devices or application processes executing locally with a database server process or remotely on a different device. Updates may be made by receiving, from a publishing application, an update to a statistic value in a database. The update may include: an indication to process the update as an accumulation update to the statistic value, an accumulation value to apply, and an indication of a key value pair to identify the statistic value to update. Upon receipt, a database server process may obtain access control as appropriate, obtain a current value for the update, apply the accumulation value to the current value, and store the result value as the new statistic value. Updates may be made by client publishers without client publishers being aware of a current value of the statistic. The statistic may represent a network wide operational parameter.

Abstract: A system and method is provided for switching file systems underneath working processes. An exemplary method includes identifying a process running on an operating system of a computing device that is using a file on a first file system and temporarily suspending execution of the process. Moreover, the method includes identifying existing references of the process to access the file on the first file system during execution of the process and replacing the existing reference of the process with a new reference for the process to access a second file on a second file system during execution of the process. Moreover, the second file on the second file system corresponds to the first file on the first file system. Finally, the method includes resuming execution of the process on the computing device.

Abstract: A data storage method includes determining a first check value of a first version of a target object, obtaining a second check value of a second version of the target object, creating a data block comprising the first check value and the second check value, and storing the data block in a blockchain, where the data block stored in the blockchain is immutable.

Abstract: Disclosed is a computer program stored in a computer readable storage medium, which includes encoded commands, in which when the computer program is executed by one or more processors of a computer system, the computer program allows the one or more processor to perform the following steps for indexing. The steps may include: deciding that a first leaf node is split in a tree index data structure including a parent node including one or more indexes, and the first leaf node and a second leaf node which are leaf nodes linked with the parent node through a pointer; generating a 1-2nd leaf node which is a next node of the first leaf node; storing in the 1-2nd leaf node an index to be split among indexes stored in the first leaf node; and linking the 1-2nd leaf node and the second leaf node to the pointer.

Abstract: Methods and apparatus are disclosed regarding an e-commerce system that promotes sales of products based on product comparisons. Some embodiments may present a marketing message that justifies a price difference between presented products based on attribute differences between the presented products.

Abstract: A method and system for migrating data and metadata from a first backup system to a second backup system via a content staging system is disclosed. The system accesses the backup data from the first backup system and restores it, along with the associated metadata, to a staging system. A metadata file is created at the staging system which comprises of the metadata that is to be migrated to the second backup system. The system then migrates the data from the staging system to the second backup system. The metadata is also migrated to the second backup system in a format such that it can be indexed. As a result, the migrated data can be browsed and searched based on one or more search criteria based on the associated metadata. Other details are provided herein.

Abstract: The disclosed computer-implemented method for performing node failovers may include: (1) initiating, during a failover of a first node to a second node, a grace period for the first node and the second node; (2) writing a new lock, indicating an internet protocol (IP) address, to a memory device of the second node, while maintaining: (A) an old lock of the IP address in a memory device of the first node, and (B) locks of nodes other than the first and second nodes; (3) transferring the old lock from the first node to the new lock of the second node, where requests to change the locks of nodes other than the first and second nodes are denied during transferring; and (4) stopping the grace period. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: Novel key ticketing technology includes an example method in which a first request associated with a first object storage operation is received. The first request includes a first timestamp associated with the first object storage operation and a first object identifier identifying a first object associated with the first object storage operation. The method calculates a first inverse timestamp based on the first timestamp, and generates a first object key corresponding to the first object storage operation. The first object key includes at least the first object identifier and the first inverse timestamp. The method further inserts a first entry including the first object key into a key data store at a position relative to other object key entries based on the first object identifier and the first inverse timestamp included in the first object key.

Abstract: A note-type personal computer according to the present invention has an LCD for displaying information stored in an internal storage provided therein, and an external storage or an external picture server connected thereto, via the internet. And, operation for the information stored in the respective storages is performed by the user in the same procedure using operation units such as a keyboard, a touch pad, with indication on the LCD confirmed. When the information stored in the picture server is displayed, the LCD displays auxiliary information indicative of this notice. The LCD displays the auxiliary information using a different folder name, or displays the auxiliary information on the background of a display area of the LCD. So, the user can confirm contents on the internet easily without the need of performing complicated operations.

Abstract: Techniques related to instance recovery using Bloom filters are disclosed. A multi-node node database management system (DBMS) includes a first database server instance and a second database server instance. A recovery set includes a set of data blocks that have been modified by a first database server instance and not persisted. A Bloom filter is generated to indicate whether data blocks are excluded from the recovery set. The Bloom filter is sent to the second database server instance, which determines whether the Bloom filter indicates that a particular data block is excluded from the recovery set. Based on determining that the Bloom filter indicates that the particular data block is excluded from the recovery set, access to the particular data block is granted.

Abstract: The described technology relates to a publish-subscribe message framework in which an application, decomposed to a plurality of processing stages, is run by executing respective processing stages of the application asynchronously and simultaneously with each other. Communications between the respective processing stages may exclusively be in accordance with the publish-subscribe execution model. The described publish-subscribe framework provides for processing stages to be executed in a multi-process and/or multi-threaded manner while also enabling the distribution of the processing stages to respective processing resources in a multi-processor/multi-core processing environment. An example electronic exchange application and a corresponding example exchange gateway application are described.

Abstract: Embodiments include a method, apparatus and computer program product for providing access to a database data source during database maintenance. The method includes initiating maintenance of the database data source and managing the database maintenance to allow concurrent access to the database data source.

Abstract: Disclosed are systems and methods for improving interactions with and between computers in content searching, generating, hosting and/or providing systems supported by or configured with personal computing devices, servers and/or platforms. The systems interact to identify and retrieve data within or across platforms, which can be used to improve the quality of data used in processing interactions between or among processors in such systems. The disclosed systems and methods provide an improved messaging platform that enables the creation and communication of locked electronic messages to recipients, where the message is automatically unlocked for recipient viewing only upon satisfaction of a real-world condition set by the sending user. Upon creating the message, the sender sets time, date and/or geographical restrictions for viewing the message, such that only upon those set restrictions being satisfied is the message delivered and viewable on the recipient user's device.

Abstract: Data records of a data set can be stored in multiple main part fragments retained in on-disk storage. Each fragment can include a number of data records that is equal to or less than a defined maximum fragment size. Using a compression that is optimized for each fragment, each fragment can be compressed. After reading at least one of the fragments into main system memory from the on-disk storage, an operation can be performed on the fragment or fragments while the in the main system memory.

Abstract: A volume rehost tool migrates a storage volume from a source virtual server within a distributed storage system to a destination storage server within the distributed storage system. The volume rehost tool can prevent client access to data on the volume through the source virtual server until the volume has been migrated to the destination virtual server. The tool identifies a set of storage objects associated with the volume, removes configuration information for the set of storage objects, and removes a volume record associated with the source virtual server for the volume. The tool can then create a new volume record associated with the destination virtual server, apply the configuration information for the set of storage objects to the destination virtual server, and allow client access to the data on the volume through the destination virtual server.

Abstract: The subject matter disclosed herein provides methods for the forced ordering of a dictionary based on row identifier values. A plurality of concurrent transactions can be handled in an in-memory database. At least one of the transactions can include at least one write operation to a dictionary. Each write operation can be assigned a row identifier (ID). At least one of the write operations can be written to the dictionary out of sequence. The sequence can be based on the row ID. Each row ID in the dictionary can be mapped to a corresponding value identifier in the dictionary. The dictionary can position the value identifiers so that the corresponding row IDs are in a sorted sequential order based on the row ID. Related apparatus, systems, techniques, and articles are also described.

Abstract: A method for allocating non-conflicting inode numbers between files generated at a first location and files generated at another location is provided. The method includes providing an inode number allocation rule table indicating availability for assignment a plurality of inode number allocation rules associated with the first location and the another location, generating a fileset at the first location by assigning an available inode number allocation rule to the fileset, registering, in the inode number allocation rule table, information associated with the fileset, and generating a file at the first location by determining the fileset within which to generate the file; and allocating an inode number for the file based on the available inode number allocation rule assigned to the fileset.

Abstract: Techniques for processing “destructive” database statements are provided. Destructive database statements, when processed, cause metadata of a database object to be changed. Examples of such database statements include ones that delete an index, that set a column as unused, and that drop a constraint on a column. When such a statement is received, a change is made to metadata of a database object. Such a metadata change may involve setting an index as unusable, disabling a constraint, or invalidating a cursor. After the metadata change, a first time is determined. Then, it is determined when one or more database transactions that were pending at the first time have committed. After those database transaction(s) have committed, one or more operations are performed, such as dropping an index or dropping a constraint.

Abstract: The present disclosure relates to systems and methods that require no data redistribution during a database scaling process. Requiring no data redistribution (also called data migration) can save many hours, or days, or even weeks of overhead during database scaling process. Embodiments of the present disclosure disclose only exchanging control messages among database servers. The control messages may include system configuration information, network topology information, database and table structure information, and any other kind of meta-data information. In the said embodiments, database servers are grouped into clusters. A database server may be a physical computer or a virtual server. Data stored in the existing database servers is not migrated to the new servers. When new database servers are added to the distributed database system, a new cluster is formed to include the new servers.

Abstract: Embodiments of the present disclosure provide a method and apparatus for distributed data processing. The method comprises: receiving from an upstream node an input message attached with a shared count, the shared count being used for determining a processing status of a root message associated with the input message; processing the input message to generate one or more new messages; allocating to each of the one or more new messages a respective new shared count based on the received shared count; and transmitting the one or more new messages to one or more downstream nodes respectively. Compared with the prior art, the methods and apparatuses for distributed data processing according to the embodiments of the present disclosure can effectively reduce network traffic overheads and the consumed CPU and memory resources, and would be scalable for different topologies of various distributed data processing systems.

Abstract: Managing idempotent operations is provided. A request to perform an operation on a system of record is received from a client via a network. An idempotency resolver is queried to determine whether a result corresponding to the operation is located in a mapping table of the idempotency resolver. In response to determining that the result corresponding to the operation is in the mapping table of the idempotency resolver, the result corresponding to the operation that is located in the mapping table of the idempotency resolver is sent to the client via the network.

Abstract: A method includes receiving a request to store a record in a base data set and determining whether the base data set can accommodate the record. In the event the base data set cannot accommodate the record, the method automatically creates an overflow data set to accommodate the record, stores the record in the overflow data set, and updates an index of the base data set to include a key associated with the record. The key points to the overflow data set as containing the record. In certain embodiments, the base data set and overflow data set are both keyed VSAM data sets. A corresponding system and computer program product are also disclosed.

Abstract: A technique for managing storage space in a data storage system implements data objects in respective files. In response to an instruction to convert a set of such files from thin to thick or from thick to thin, the data storage system checks whether it has enough available storage space to accommodate the set of files if conversion were to proceed. If so, conversion is performed, and each of the set of files is converted from thin to thick or from thick to thin, in accordance with the instruction.

Abstract: Technologies are described for facilitating transaction processing within a database environment. A commit protocol provides for the atomic commit or rollback of a transaction that includes an operation that modifies a metadata entity of the database system and one or more other operations that modify metadata entities or data records of the database system. Innovations are provided for detecting and resolving deadlocks that may arise during transaction processing. Innovations are also provided for providing versioning of metadata entities, including invalidating metadata entities cached at a slave node during the commit at a master node of a transaction that creates a new version of the metadata entity.

Abstract: The various embodiments described herein include methods, devices, and systems for reading and writing data from a database table. In one aspect, a method of reading and writing data from a database table, includes: (1) initiating a write transaction to write data to a first non-key column of a row of the database table, the database table having a plurality of rows, each row comprising a primary key and a plurality of non-key columns; (2) locking the first non-key column; and (3) in accordance with a determination that the second non-key column is not locked, initiating a read transaction to read data from the second non-key column, where initiation of the read transaction occurs prior to completion of the write transaction.

Abstract: Methods and systems for distributed transaction processing include assigning portions of a logical unit of work to one or more transaction participants. Resource usage information relating to the portions of the logical unit of work is tracked from the respective one or more transaction participants. A last participant is determined based on the tracked resource usage information using a processor. The logical unit of work is resolved. Resolving the logical unit of work includes sending a prepare flow to each of the transaction participants except the last participant to optimize resolution efficiency.