A DBMS receives a database-access request that includes an instruction to non-destructively read a database table row. The DBMS assigns the request a TSN identifier and creates a TSN image that identifies all TSNs assigned to transactions that are not yet committed. The DBMS traverses a linked list of log entries that identifies a chronological history of transactions performed on the same row. The DBMS infers that the table row currently contains data stored by the most recently logged transaction that is not contained in the TSN image and that has thus been committed. The DBMS then continues to process statements of the transaction based on the assumption that the row contains the inferred value. The DBMS performs this procedure without acquiring a shared lock on the data page or on the index leaf page that points to the table row.

Systems, methods, and computer-readable media are disclosed for an improved database. The systems, methods, and computer-readable media described herein may enhance the response time of databases and improve user experiences. In an example method described herein, a database monitoring system may receive instructions to perform one or more data monitoring operations comprising counting an occurrence of a first value within at least a portion of items stored in a database. The method may include determining a length of a first window of time and fetching, from a first location of a data store of the database, data indicative of a total count of the occurrence of the first value at a time associated with the beginning of the first window of time. In turn, the monitoring system may store data representing the first count in the first memory.

A computer-implemented method, medium, and system for global deadlock detection in a hybrid database for transactional and analytical workloads are disclosed. In one computer-implemented method, a daemon is launched on a coordinator segment in a massively parallel processing (MPP) database, where the MPP database is a hybrid database for both transactional workloads and analytical workloads. A respective local wait-for graph for each of a plurality of segments in the MPP database is collected periodically, where each of the plurality of segments includes the coordinator segment or a worker segment of a plurality of worker segments in the MPP database. A global wait-for graph that includes all collected local wait-for graphs is built. The global wait-for graph is used to determine that a global deadlock exists in the MPP database. The global deadlock is broken using one or more predefined policies in response to determining that the global deadlock exists.

A method, an apparatus, and an electronic device for processing a data transaction are disclosed. The method includes receiving an application request from a client to perform a data operation in a target data partition; creating a corresponding data transaction according to the application request, and assigning a transaction identifier to the data transaction; returning the transaction identifier that is assigned to the data transaction to the client; performing the data operation based on the target data partition according to the data operation carrying the transaction identifier and sent by the client; and processing the data transaction according to a transaction instruction sent by the client. The method enables a data operation to implement transactional attributes, and to satisfy a transactional nature of the data operation. Moreover, the service logic of data transactions implemented by the method is relatively simple, thus ensuring that data services have a good transactional nature.

A distributed database compaction system can perform compaction for transactional queries in an asynchronous matter without affecting completion of the queries. The compaction system can implement asynchronous transformation of key pairs in the database, and older keys can be periodically purged using a scheduled compactor. Subsequent queries use the compacted stored keys to perform efficient queries with direct reads of committed transactions and more efficient access to key values stores of the distributed database.

The present disclosure provides a method of reading data maintained in a tree data structure, such as B+ tree, using near data processing (NDP) in a cloud native database. According to embodiments, a desired LSN will be used in NDP page reads on the master computing node (e.g. master SQL node). When the master computing node (e.g. master SQL node) reads the regular page, the maximum desired LSN (e.g. the latest page version number) for that regular page will be used. Embodiments use features of the desired LSN and page locking, wherein correct versions of pages can be obtained by using the desired LSN associated with a page, in combination with page locking, and can enable the reading of a consistent tree structure and achieve good read/write concurrency.

The present disclosure involves systems, software, and computer implemented methods for key pattern management. One example method includes receiving a query for a logical database table from an application. A determination is made as to whether the query is a write query. In response to determining that the query is a write query, a determination is made as to whether the query complies with a key pattern configuration that describes keys of records included in a physical database table that is part of a logical table implementation. The physical table includes records of the logical database table that are allowed to be written by the application. The write query is redirected to the physical database table in response to determining that the query complies with the key pattern definition. The query is rejected in response to determining that the query does not comply with the key pattern configuration.

Provided is a method for performing a file system consistency check. The method comprises calculating, by a first thread that does not have access to an inode table, file block addresses for one or more files to be checked by the thread. The method further comprises collecting validity information for the one or more files. The method further comprises reading information relating to the one or more files from the inode table. The reading is performed in response to the thread being given access to the inode table after the calculating operation. The method further comprises validating the information by comparing the information from the inode table to the validity information.

A method includes receiving, by a computing device, a first transaction from a user device for a first version of a database record; generating, by the computing device, a bit for the database record; receiving, by the computing device, a second transaction from a second user device for a second version of the database record; locking, by the computing device, the database record; determining, by the computing device, a modification between the first version of the database record and the second version of the database record; and updating, by the computing device, the bit in response to the modification.

Methods and systems of inserting image files into a container are described herein. One method includes overseeing a submission of images to containers, retrieving a job of inserting images into the container, and inserting images into the container by, for each of the plurality of images: (i) reading and analyzing source data including the image; (ii) opening the container, which includes records, where the image will be stored; (iii) determining whether the source data is valid to be entered into a record; (iv) responsive to a determination that the source of data is valid, preparing metadata; (v) writing the record into the container; and (vi) marking a status flag/mark of the record as being updated while writing the record into the container.