Abstract: A database management system generates a cache entry system view of a database cache. Also, a new column is generated for the cache entry system view, where the new column is an ENTRY_HASH column to identify each entry of the database cache. In an example, the database management system detects a request to remove a given entry of the database cache, where the request includes a given ENTRY_HASH value to locate the given entry of the database cache. In response to receiving the request, the database management system identifies the given entry of the database cache based on the given ENTRY_HASH value. Then, the database management system removes the given entry of the database cache. Also, the database management system notifies a cache manager that the given entry has been removed.

Abstract: The present disclosure involves systems, software, and computer implemented methods for improved design and implementation of data access metrics for automated physical database design. An example method includes identifying a database workload for which index advisor access counters are to be tracked. Each SQL statement in the database workload is executed. For each SQL statement, attribute sets are determined for which a selection predicate filters a result for an SQL statement. An output cardinality of each selection predicate is determined. A logarithmic counter for an attribute set corresponding to the selection predicate is determined based on the output cardinality of the selection predicate. The determined logarithmic counter is incremented. Respective values for logarithmic counters of the determined attributes are provided to an index advisor. The index advisor determines attribute sets for which to propose an index based on the logarithmic counters of the respective attribute sets.

Abstract: Methods, systems, and computer-readable storage media for receiving, from a database client, an asynchronous lookup request including a key representative of a query and, in response, returning a value handle including a value promise, receiving, from the database client, a get request based on the value promise, determining that a query result corresponding to the key is unavailable in a results cache and that the key is in an unlocked state, and in response, returning a null pointer and a first key lock status to the first database client, receiving, from the database client, a key, value pair including the key and a value, the value comprising the query result, and storing the key, value pair in the results cache.

Abstract: The present disclosure involves systems, software, and computer implemented methods for improved design and implementation of data access metrics for automated physical database design. An example method includes identifying a database workload for which index advisor access counters are to be tracked. Each SQL statement in the database workload is executed. For each SQL statement, attribute sets are determined for which a selection predicate filters a result for an SQL statement. An output cardinality of each selection predicate is determined. A logarithmic counter for an attribute set corresponding to the selection predicate is determined based on the output cardinality of the selection predicate. The determined logarithmic counter is incremented. Respective values for logarithmic counters of the determined attributes are provided to an index advisor. The index advisor determines attribute sets for which to propose an index based on the logarithmic counters of the respective attribute sets.

Abstract: Systems and methods include reception, at a database instance hosting a plurality of database tenants, of a statement for execution in a first database session associated with a first tenant, determination of first tenant-level resource limits associated with the database session, determination, for one or more resources, of a total amount consumed by the first database session, determination, based on the first tenant-level resource limits and the total amount of the one or more resources consumed by the first database session, of whether the statement can be executed by the database instance in compliance with the first tenant-level resource limits, and execution of the statement if it is determined that the statement can be executed by the database instance in compliance with the first tenant-level resource limits.

Abstract: A device for treating tissue includes a capsule extending longitudinally from a proximal end to a distal end and including a channel extending therethrough, the capsule releasably coupled to a proximal portion of the device and clip jaws, proximal ends of which are slidably received within the channel of the capsule so that the clip jaws are movable between an open configuration and a closed configuration. Clip jaws are configured so that a distance between the distal ends of the clip jaws in an open configuration is between 15 and 18 millimeters. Clip jaws further include barbs extending from a distal portion thereof.

Abstract: A database management system generates a cache entry system view of a database cache. Also, a new column is generated for the cache entry system view, where the new column is an ENTRY_HASH column to identify each entry of the database cache. In an example, the database management system detects a request to remove a given entry of the database cache, where the request includes a given ENTRY_HASH value to locate the given entry of the database cache. In response to receiving the request, the database management system identifies the given entry of the database cache based on the given ENTRY_HASH value. Then, the database management system removes the given entry of the database cache. Also, the database management system notifies a cache manager that the given entry has been removed.

Abstract: Systems and methods include establishment of a first authenticated database session with a first database user of a database instance hosting a plurality of tenants, determination of a first tenant of the plurality of tenants based on a mapping of the first database user to the first tenant, determination of a first workload class based on the first tenant, and management of resource consumption of the first authenticated database session based on the first workload class.

Abstract: A transaction processing protocol for serverless database management systems can use a transaction scheduler to guarantee consistent serializable execution though analysis of the access pattern of transaction types and appropriate ordering of the transaction's events at runtime. A transaction topology is determined for each type of transaction and these are combined and used to generate a serialization graph. Cycles in the serialization graph are identified and breaking transaction types which may break the cycles are determined. When transaction requests are received, a breaking type of transaction is scheduled as a last transaction in the current epoch and later transactions not having the breaking transaction type are scheduled to execute in the next epoch.

Abstract: A device for treating tissue includes a capsule extending longitudinally from a proximal end to a distal end and including a channel extending therethrough, the capsule releasably coupled to a proximal portion of the device and clip jaws, proximal ends of which are slidably received within the channel of the capsule so that the clip jaws are movable between an open configuration and a closed configuration. Clip jaws are configured so that a distance between the distal ends of the clip jaws in an open configuration is between 15 and 18 millimeters. Clip jaws further include barbs extending from a distal portion thereof.

Abstract: Systems and methods include creation of a first instance of a tenant object in a database instance, association of the first instance of the tenant object with a first plurality of database artifacts including first data associated with the first instance of the tenant object, creation of a second instance of the tenant object in the database instance, association of the second instance of the tenant object with a second plurality of database artifacts including second data associated with the second instance of the tenant object, and reception and response to queries on the first data associated with the first instance of the tenant object and to queries on the second data associated with the second instance of the tenant object.

Abstract: A stream of database transactions are received and conflicts between transaction types are determined. When a conflict is determined, job components forming a database architecture are configured to execute a first transaction, and in response to completing the first transaction, job components forming the database architecture are reconfigured to execute a second transaction.

Abstract: Provided are systems and methods for creating histograms with distinct value sketches integrated therein and for query processing based on the histograms with distinct value sketches. In one example, the method may include storing a histogram that comprises a representation of a bucket of data from a database and that includes a distinct value sketch with a distinct value attribute that identifies an estimated number of distinct values within the bucket of data, receiving a database query, generating a query execution plan for the database query based on the distinct value attribute of the bucket within the distinct value sketch embedded within the histogram, and executing the database query on the bucket of data from the database based on the generated query execution plan.

Abstract: A method, a system, and a computer program product for decompressing data. One or more compressed blocks in a set of stored compressed blocks responsive to a request to access data in the set of stored compressed blocks are identified. String prefixes inside the identified compressed blocks are decompressed using front coding. String suffixes inside the identified compressed blocks are decompressed using a re-pair decompression. Uncompressed data is generated.

Abstract: According to some embodiments, methods and systems may be associated with a cloud computing environment. A workload prediction framework may receive observed workload information associated with a database in the cloud computing environment (e.g., a DataBase as a Service (“DBaaS”)). Based on the observed workload information, a Statement Arrival Rate (“SAR”) prediction may be generated. In addition, a host variable assignment prediction may be generated based on the observed workload information. The workload prediction framework may then use the SAR prediction and the host variable assignment prediction to automatically create a workload prediction for the database. A physical database design advisor (e.g., a table partitioning advisor) may receive the workload prediction and, responsive to the workload prediction, automatically generate a recommended physical layout for the database (e.g., using a cost model, the current physical layout, and an objective function).

Abstract: Systems and methods include reception of an instruction to recover a first database tenant of a first database instance to a first point in time, the first database tenant associated with first database artifacts of the first database instance, and the first database instance including two or more database tenants and, in response to the instruction, creation of a second database instance, selection of backup data of the first database instance based on the first point in time, execution of a recovery of the backup data on the second database instance, export of second database artifacts of the first database tenant from the second database instance to a storage, truncation of the first database artifacts from the first database instance, import of the second database artifacts from the storage to the first database instance, and deletion of the second database instance.

Abstract: A database management system is described that can encode data to generate a plurality of data vectors. The database management system can perform the encoding by using a dictionary. The database management system can adaptively reorder the plurality of data vectors to prepare for compression of the plurality of data vectors. During a forward pass of the adaptive reordering, most frequent values of a data vector of the plurality of data vectors can be moved-up in the data vector. During a backward pass of the adaptive reordering, content within a rest range of a plurality of rest ranges can be rearranged within the plurality of data vectors according to frequencies of the content. The reordering according to frequency can further sort the rest range by value. Related apparatuses, systems, methods, techniques, computer programmable products, computer readable media, and articles are also described.

Abstract: Methods, systems, and computer-readable storage media for receiving, from a database client, an asynchronous lookup request including a key representative of a query and, in response, returning a value handle including a value promise, receiving, from the database client, a get request based on the value promise, determining that a query result corresponding to the key is unavailable in a results cache and that the key is in an unlocked state, and in response, returning a null pointer and a first key lock status to the first database client, receiving, from the database client, a key, value pair including the key and a value, the value comprising the query result, and storing the key, value pair in the results cache.

Abstract: A system includes determination of a query comprising z predicates, determination of known selectivities of each of a set of conjuncts of the z predicates, and estimation of selectivities of all conjuncts of the z predicates based on the known selectivities and a recursive determination of Cx, where x represents selectivities of all complete conjuncts of the z predicates and C is a complete design matrix complete design matrix (ci,j)=1 if i?j, else 0, having indices [0, 2z?1].

Abstract: Embodiments of the present disclosure include techniques for cooperative memory management. In one embodiment, a database management system includes a memory manager for managing a memory buffer. The memory buffer is configured to allocate memory to table data and temporary data dynamically. In some embodiments, table data memory allocations are reduced and temporary data memory allocations are increased to process queries. Temporary data memory allocations may be increased to store temporary data associated with one or more portions of a query. The memory buffer reallocates table data memory allocations and temporary data memory allocations as needed to more efficiently use available memory.