Abstract: A system for an in-memory row storage architecture can be provided. In some implementations, the system performs operations including processing a database statement comprising a first database transaction affecting one or more rows in an in-memory row store, registering the database statement at a start of execution of the database statement, the start of execution occurring at a first time, unregistering the registered database statement at an end of execution of the database statement, determining a second time at which execution of an oldest currently registered database statement was started, assigning a garbage collection thread to a second database transaction committed at a third time and affecting at least one row of the plurality of rows, and activating the garbage collection thread to reclaim memory within the in-memory row store when the third time is less than the second time. Related systems, methods, and articles of manufacture are also described.

Abstract: A system for an in-memory row storage architecture can be provided. In some implementations, the system performs operations comprising determining that data stored at a first location in a persistent page store is active, copying the data to a second location in an in-memory row store in response to determining that the data is active, indexing the data in an index table in response to determining that the data is active, accessing the data at the second location in the in-memory row store based on the index table, and performing an update of the data in the in-memory row store. Related systems, methods, and articles of manufacture are also described.

Abstract: A transaction descriptor associated with a vertical chain of row versions is received. The vertical chain of row versions is traversed. The vertical chain is part of a grid structure formed by a number of vertical chains intersected with a number of horizontal chains. A link to a current row version is terminated. A link from the current row version to an older row version in a horizontal chain is locally stored and terminated. The older row version is set as ready for garbage collection. The current row version is set as ready for garbage collection. A link from the current row version to a next row version in the horizontal chain is locally stored and terminated. The next row version is appointed as current.

Abstract: Example embodiments of a database employing an efficient form of multi-version concurrency control (MVCC) are described. In an example embodiment, in response to receiving an update command for a first row of a plurality of rows of a database, an image of the first row stored in a first memory area is stored in a second memory area. In a third memory area storing a first database structure and associated pointer corresponding to the image of the first row stored in the first memory area, a second data structure and associated pointer corresponding to the image of the first row in the second memory area are stored. The second data structure is linked to the first data structure. The image of the first row in the first memory area is overwritten with an image of a new version of the first row provided in the update command.

Abstract: Techniques of implementing partition level operations with concurrent activities are disclosed. A first operation can be performed on a first partition of a table of data. The first partition can be one of a plurality of partitions of the table, where each partition has a plurality of rows. A first partition level lock can be applied to the first partition for a period in which the first operation is being performed on the first partition, thereby preventing any operation other than the first operation from being performed on the first partition during the period the first partition level lock is being applied to the first partition. A second operation can be performed on a second partition of the table at a point in time during which the first operation is being performed on the first partition.

Abstract: Among the various aspects of the present disclosure is the provision of a device with multiple microenvironments and methods of use and manufacture thereof. An aspect of the present disclosure provides for a device for evaluating cell invasion. Another aspect provided by the present disclosure includes a method of making a device for evaluating cell invasion. Another aspect to the present disclosure provides for a method of testing a drug in vitro. Another aspect of the present disclosure provides for a method of identifying targets.

Abstract: Techniques of implementing partition level operations with concurrent activities are disclosed. A first operation can be performed on a first partition of a table of data. The first partition can be one of a plurality of partitions of the table, where each partition has a plurality of rows. A first partition level lock can be applied to the first partition for a period in which the first operation is being performed on the first partition, thereby preventing any operation other than the first operation from being performed on the first partition during the period the first partition level lock is being applied to the first partition. A second operation can be performed on a second partition of the table at a point in time during which the first operation is being performed on the first partition.

Abstract: The embodiments described in this disclosure include a multi-layer data structure configured to access rows, pages, and locks stored in memory of a database. The multi-layer data structure may include a row mapping table configured to convert a row identifier of a row in the database into a row address of the row to be accessed stored in a cache memory. The row mapping table may be used to compare bits of the row identifier with corresponding bits of the row address in the cache memory. Each layer of multi-layer row mapping table can be configured to store certain of the bits of the row address and the row address can be determined by comparing the bits of the row address with the corresponding bits of the row identifier at each layer of the data structure.

Abstract: Disclosed herein are system, method, and computer program product embodiments for synchronizing an unsynchronized distributed database system. An embodiment operates by locking, by a second node, partitions in the second node based on first information received from, a first node responsive to execution of partition utility based on a first query received by the first node. Blocking, by the second node, a second query to a data portion of the partitions in the second node based on the first information. Locking, by the second node, second node object metadata based on second information received from the first node. Receiving, by the second node, changes to first node object metadata and applying the changes to the second node object metadata. Unlocking, by the second node, the partitions in the second node and the second node object metadata while unblocking the second query.

Abstract: A transaction descriptor associated with a vertical chain of row versions is received. The vertical chain of row versions is traversed. The vertical chain is part of a grid structure formed by a number of vertical chains intersected with a number of horizontal chains. A link to a current row version is terminated. A link from the current row version to an older row version in a horizontal chain is locally stored and terminated. The older row version is set as ready for garbage collection. The current row version is set as ready for garbage collection. A link from the current row version to a next row version in the horizontal chain is locally stored and terminated. The next row version is appointed as current.

Abstract: Synchronization of metadata structures in a multi-threaded system includes receiving, by a first thread of a processing device, a request for a metadata structure located in a first cache associated with an object, obtaining, by the first thread of the processing device, a synchronization mechanism associated with the first cache, holding, by the first thread of the processing device, the metadata structure associated with the object, receiving, by a second thread of the processing device, a request for the metadata structure in a second cache associated with the object, obtaining, by the second thread of the processing device, a synchronization mechanism associated with the second cache and informing the second thread of the processing device that the metadata structure associated with the object is not available.

Abstract: Techniques of implementing partition level operations with concurrent activities are disclosed. A first operation can be performed on a first partition of a table of data. The first partition can be one of a plurality of partitions of the table, where each partition has a plurality of rows. A first partition level lock can be applied to the first partition for a period in which the first operation is being performed on the first partition, thereby preventing any operation other than the first operation from being performed on the first partition during the period the first partition level lock is being applied to the first partition. A second operation can be performed on a second partition of the table at a point in time during which the first operation is being performed on the first partition.

Abstract: Techniques of implementing partition level operations with concurrent activities are disclosed. A first operation can be performed on a first partition of a table of data. The first partition can be one of a plurality of partitions of the table, where each partition has a plurality of rows. A first partition level lock can be applied to the first partition for a period in which the first operation is being performed on the first partition, thereby preventing any operation other than the first operation from being performed on the first partition during the period the first partition level lock is being applied to the first partition. A second operation can be performed on a second partition of the table at a point in time during which the first operation is being performed on the first partition.

Abstract: Techniques of implementing partition level operations with concurrent activities are disclosed. A first operation can be performed on a first partition of a table of data. The first partition can be one of a plurality of partitions of the table, where each partition has a plurality of rows. A first partition level lock can be applied to the first partition for a period in which the first operation is being performed on the first partition, thereby preventing any operation other than the first operation from being performed on the first partition during the period the first partition level lock is being applied to the first partition. A second operation can be performed on a second partition of the table at a point in time during which the first operation is being performed on the first partition.

Abstract: Synchronization of metadata structures in a multi-threaded system includes receiving, by a first thread of a processing device, a request for a metadata structure located in a first cache associated with an object, obtaining, by the first thread of the processing device, a synchronization mechanism associated with the first cache, holding, by the first thread of the processing device, the metadata structure associated with the object, receiving, by a second thread of the processing device, a request for the metadata structure in a second cache associated with the object, obtaining, by the second thread of the processing device, a synchronization mechanism associated with the second cache and informing the second thread of the processing device that the metadata structure associated with the object is not available.

Abstract: Embodiments include a method, apparatus and computer program product for executing a database transaction in parallel using subtransactions. The method includes receiving a transaction at an application, the transaction having a first statement and a second statement, and determining whether operation of the first statement is independent from operation of the second statement. When it is determined that operation of the first statement is independent from operation of the second statement, assigning the first statement to a first subtransaction and the second statement to a second subtransaction, the first and second subtransactions being part of a transaction group. The method further includes executing the subtransactions using resources of the database. Finally, when execution of all of the subtransactions have successfully completed, committing all of the subtransactions.