Abstract: Pages are loaded into a resource container from physical disk storage into memory of an in-memory database. The resource container includes a resource provider and the pages include a plurality of large object pages (LOBs). Thereafter, the resource provider is used to allocate portions of the memory and control blocks to the pages. A job is triggered when an amount of memory allocated to LOBs by the resource provider exceeds a predefined first level. The job evicts LOBs from memory until the amount of memory allocated to LOBs is below a predefined second level.

Abstract: A page is loaded into memory of an in-memory database system. Thereafter, it is determined whether to reorganized the page based on how such page is used. Based on such determination, the page is either reorganized by filling any free space gaps in memory and then, use of the reorganized page is enabled or, otherwise, use of the page is enabled without reorganization.

Abstract: Allocation of an entry in a variable size entry container is initiated in an in-memory database system. The variable size entry container includes a plurality of pages forming a chain. Thereafter, it is determined whether free space is found within the pre-existing pages. If free space is found, the entry is allocated in the free space. Otherwise, a new page is created and appended to the chain so that the entry can be allocated on such new page.

Abstract: A savepoint is initiated in an in-memory database system that is associated with a plurality of modified pages and comprises a pre-critical phase, a critical phase, and a post-critical phase. Thereafter, as part of the critical phase, a physical page number is assigned to each page in the critical phase. Further, as part of the critical phase, each page assigned a physical page number is individually locked. Subsequently, each page is handed over from a corresponding first thread to a corresponding second thread to copy such page into a corresponding shadow page as part of the post-critical phase.

Abstract: A plurality of pages are loaded into an in-memory data container forming part of an in-memory database as part of a backup process. Memory available for other database operations in the database are monitored. When the monitored available memory is below a pre-defined level, at least a portion of the pages loaded into the data container are flushed into physical persistence. Related apparatus, systems, and methods are also described.

Abstract: Resources are loaded into a resource container in an in-memory database system in which pages are loaded into memory and having associated physical disk storage. Each resource is assigned a new time stamp when such resource is loaded into the resource container. At least some of the references are subsequently accessed and time stamps associated with these accesses resources are selectively updated based on the type of access. These time stamps are later used to evict least recently used resources (as indicated by their time stamps) from the resource container.

Abstract: Systems and methods are described herein for system critical phase lock job inhibitors. Acquisition of a consistent change exclusive lock is initiated. A job request having a scope object is received. Execution of the job request and generation of a replacement job associated with the job request is prohibited based on the scope object indicating that the job requires consistent change access during the consistent change exclusive lock.

Abstract: Recovery of a database system by taking the database system offline is initiated. Thereafter, recovery operations specified by a redo log of the database system are replayed. A cleanup log is generated that identifies cleanup operations occurring during the replay of the recovery operations for garbage collection. Concurrent with the startup of the database, garbage collection of the cleanup operations as specified in the database savepoint is initiated. In addition, concurrent with the replay of the recovery operations, garbage collection of the cleanup operations specified by the cleanup log is initiated. The amount of parallelization of the garbage collection can be varied based on utilized processor resources. The database system is later brought online after all of the recovery operations are replayed.

Abstract: Recovery of a database system can be initiated by taking the database system offline. Thereafter, recovery operations specified by a redo log of the database system are replayed. During the replaying, updates to pages implicated by the recovery operations are blocked. In parallel, modified pages are flushed to physical disk storage. The database is later brought online after all of the recovery operations are replayed.

Abstract: Metadata is stored within a database for each of a plurality of objects in different frames associated with a structure descriptor (e.g., a container directory entry, etc.). The frames are part of a metadata page and each comprising an object and a header specifying a version identifier for the object and a size of the object. The structure descriptor initially is built for a first build identifier. Thereafter, upon the structure descriptor changing from the first build identifier to a second build identifier, at least one of the objects that require migration is identified. The identification is based on the version identifier for the object being different from the second build identifier. In response, the identified objects are migrated from their corresponding frame to a new frame. The new frame includes the objects and new headers that include a version identifier equal to the second build identifier.

Abstract: A request is received for a first non-exclusive lock to read a page in a database. Thereafter, execution of the at least one non-exclusive lock is initiated. Later, a request for an exclusive lock to modify the page in the database is received. Subsequently, a request is received for a second non-exclusive lock. In response, an amount of time to finish the first request and the second request is estimated. The second non-exclusive lock is allowed to execute in parallel to the first non-exclusive if the determined amount of time to finish the second non-exclusive lock is less than an estimated amount of time needed by the first non-exclusive lock. Alternatively, execution of the second non-exclusive lock is delayed to after the execution of the exclusive lock if the determined amount of time to finish the second non-exclusive lock is greater than an amount of time needed by the first non-exclusive lock.

Abstract: Execution of an exclusive lock of a page in a database is initiated. Thereafter, subsequent to the initiation of the execution of the exclusive lock, at least one non-exclusive lock for the page in the database is received. The execution of the exclusive lock is selectively timed out based on at least one savepoint statistic. While the exclusive lock is timed out, at least one of the received non-exclusive locks is executed. Further, the exclusive lock can be restarted after the execution of the at least one of the received non-exclusive locks.

Abstract: A provisional page to be filled with data is allocated in an in-memory database system in which pages are loaded into memory and having associated physical disk storage a provisional page to be filled with data. Thereafter, the provisional page is filled with data. The provisional page is register after the provisional page has been filled with data such that consistent changes in the database are not required for the provisional page prior to the registering.

Abstract: Systems and methods are described herein for job execution using system critical threads. An in-memory database system having pages loaded into a memory and having associated physical disk storage generates a safety critical thread pool. The safety critical thread pool has one or more safety critical threads associated with flushing the pages to the physical disk storage. Execution of the one or more safety critical threads is initiated within the safety critical thread pool. A job request to access data stored within the physical disk storage is received. Utilization levels of the one or more safety critical threads are monitored. Execution of the job request is permitted based on the utilization levels associated with the one or more safety critical threads.

Abstract: Checking of a database snapshot of an active database is initiated. Thereafter, an anchor page associated with a most recent snapshot that links to a restart page is read. Subsequently, the linked restart page is read. It is then initially determined, based on the reading of the anchor page and the restart page, whether the snapshot is accurate. If it is initially determined that the snapshot is not accurate, the anchor page and the restart page are re-read until a final determination is made that whether the snapshot is accurate. Alternatively, if not is initially determined that the snapshot is accurate, then data is provided (e.g., displayed, loaded into memory, transmitted to a remote computing system, stored in physical persistence, etc.) that indicates that the snapshot is accurate.

Abstract: Disclosed herein are embodiments for free-space handling in pages and in-memory containers allowing variable-size data entries. An example system may determine expanses of unallocated space, within a page loaded in memory and configured to allocate a first data entry of a first size within the page that may also allocate at least one subsequent data entry of a second size different from the first size; save, into memory, transient free-space information corresponding to the page, including first position information for a first number of expanses of contiguous unallocated space within the page; evict the page from memory, writing allocated data entries contained therein to persistent storage; store, into persistent storage, persistent free-space information corresponding to the page, including second position information for a second number of expanses of unallocated space within the page, the second number being less than the first number; and discard the transient free-space information.

Abstract: Recovery of a database system by taking the database system offline is initiated. Thereafter, recovery operations specified by a redo log of the database system are replayed. During such replay, updates to pages implicated by the recovery operations are blocked. In parallel to such blocking, modified pages are adaptively flushed to physical disk storage using a factor that is based on a number of pages written to the physical disk storage and a number of write I/O operations as part of the flushing of the modified pages. Subsequently, the database system is brought online after all of the recovery operations are replayed.

Abstract: Each of a plurality of database transactions are logged (i.e., recorded) in a log. Concurrent with the logging, one or more characteristics of the log are monitored. Thereafter, a savepoint is triggered when a pre-defined condition is met as indicated by the monitoring. The triggered savepoint can override or accelerate a savepoint that would have otherwise been triggered based on pre-specified parameters.

Abstract: Execution of a page flusher is initiated in an in-memory database system in which pages are loaded into memory and which has associated physical disk storage. Thereafter, the page flusher identifies pages that were last modified outside a pre-defined time window. The page flusher then flushes the identified modified pages to the physical disk storage.

Abstract: A record within a destination virtual file is generated on a destination node of a distributed data storage system. The record comprises a link directed to a source virtual file stored on a source node. The source virtual file is mapped to a chain of linked pages stored in a page buffer of the distributed data storage system. A request is later received at the destination node to access data defined by the destination virtual file. Data is provided, in response to the request, from the source virtual file stored on the source node using the link. Related apparatus, systems, techniques and articles are also described.