Abstract: A manager file system (MFS), implemented using an OS process, exposes a path in the native file system as the root of its file system (e.g., mount point). The MFS informs the OS kernel that any file system operation whose path contains the mount point as its prefix, should be handed over to the process by invoking an appropriate interface method that the process implements as part of its file system implementation. The MFS manages one or more applications and leverages the authentication mechanism of the OS to provide fined-grained access control of MFS managed applications.

Abstract: A shared-nothing database system is provided in which parallelism and workload balancing are increased by assigning the rows of each table to “slices”, and storing multiple copies (“duplicas”) of each slice across the persistent storage of multiple nodes of the shared-nothing database system. When the data for a table is distributed among the nodes of a shared-nothing system in this manner, requests to read data from a particular row of the table may be handled by any node that stores a duplica of the slice to which the row is assigned. For each slice, a single duplica of the slice is designated as the “primary duplica”. All DML operations (e.g. inserts, deletes, updates, etc.) that target a particular row of the table are performed by the node that has the primary duplica of the slice to which the particular row is assigned. The changes made by the DML operations are then propagated from the primary duplica to the other duplicas (“secondary duplicas”) of the same slice.

Abstract: JSON Duality Views are object views that return JDV objects. JDV objects are virtual because they are not stored in a database as JSON objects. Rather, JDV objects are stored in shredded form across tables and table attributes (e.g. columns) and returned by a DBMS in response to database commands that request a JDV object from a JSON Duality View. Through JSON Duality Views, changes to the state of a JDV object may be specified at the level of a JDV object. JDV objects are updated in a database using optimistic lock.

Abstract: JSON Duality Views are object views that return JDV objects. JDV objects are virtual because they are not stored in a database as JSON objects. Rather, JDV objects are stored in shredded form across tables and table attributes (e.g. columns) and returned by a DBMS in response to database commands that request a JDV object from a JSON Duality View. Through JSON Duality Views, changes to the state of a JDV object may be specified at the level of a JDV object. JDV objects are updated in a database using optimistic lock.

Abstract: Herein is database query acceleration from dynamic discovery of whether contents of a persistent column can be stored in an accelerated representation in storage-side memory. In an embodiment, based on data type discovery, a storage server detects that column values in a persistent column have a particular data type. Based on storage-side metadata including a frequency of access of the persistent column as an offload input column for offload computation requests on a certain range of memory addresses, the storage server autonomously decides to generate and store, in storage-side memory in the storage server, an accelerated representation of the persistent column that is based on the particular data type. The storage server receives a request to perform an offload computation for the offload input column. Based on the accelerated representation of the persistent column, execution of the offload computation is accelerated.

Abstract: LOB cache swapping is reduced by multi-LOB writing. Under multi-LOB writing, information that tracks changes made by a database transaction to multiple LOBs is retained in a LOB staging buffer after one or more LOB switches. Thus, at commit time, changes to multiple LOBs in a column may be staged in the LOB staging cache, thereby enabling the changes to be made in contiguous data blocks for all the multiple LOBs. Storing LOBs in the same column in this way improves clustering, thereby improving database performance. In addition, LOBs inserted or updated in the same database transaction are often related and accessed together within database transactions and/or query accesses. Clustering the LOB content of such related LOBs allows the LOBs to be accessed more efficiently.

Abstract: Techniques for accelerating query execution by optimizing data transfer between storage nodes and database nodes are provided. In one technique, a compute node receives a database statement and transmits a set of one or more selection criteria associated with the database statement to a storage node. Based on the database statement, the storage node retrieves a set of data blocks from storage. Each data block comprises multiple rows of an index-organized table (IOT), each row comprising a key section and a non-key section. The storage node applies the set of selection criteria to a data block, resulting in a modified data block. The storage node generates a modified header data for the modified data block and transmits the modified data block to the compute node.

Abstract: JSON Duality Views are object views that return JDV objects. JDV objects are virtual because they are not stored in a database as JSON objects. Rather, JDV objects are stored in shredded form across tables and table attributes (e.g. columns) and returned by a DBMS in response to database commands that request a JDV object from a JSON Duality View. Through JSON Duality Views, changes to the state of a JDV object may be specified at the level of a JDV object. JDV objects are updated in a database using optimistic lock.

Abstract: Techniques for adaptive, independent compression of key and non-key sections of rows in index-organized tables (IOTs) are provided. In one technique, an IOT is stored that comprises a plurality of rows, each of which comprises a key section and a non-key section. After storing the IOT, a compression technique is performed on the non-key section of each row in the plurality of rows to generate a plurality of compressed non-key sections. However, none of the key sections of the plurality of rows is compressed. In a related technique, instead of compressing the non-key section of each row, the key section of each row is compressed. In a related technique, both sections are compressed, but using different compression techniques. The compression techniques may be determined based on data access history of the different sections of the rows.

Abstract: A manager file system (MFS) runs as a user space file system. The MFS, implemented using an OS process, exposes a mount point as a communication endpoint to the single process. Mounting, unmounting, and changing configuration of individual database file systems (DBFSs) are done by overloading extended attributes on the mount point. The MFS services all DBFSs mounted at different mount points registered to the single process of the MFS and ensures optimal resource utilization among the DBFSs in the single process while guaranteeing resource isolation.

Abstract: A manager file system (MFS) runs as a user space file system. The MFS, implemented using an OS process, exposes a mount point as a communication endpoint to the single process. Mounting, unmounting, and changing configuration of individual database file systems (DBFSs) are done by overloading extended attributes on the mount point. The MFS services all DBFSs mounted at different mount points registered to the single process of the MFS and ensures optimal resource utilization among the DBFSs in the single process while guaranteeing resource isolation. Multiple MFSs may be created to manage sets of DBFSs.

Abstract: A shared-nothing database system is provided in which parallelism and workload balancing are increased by assigning the rows of each table to “slices”, and storing multiple copies (“duplicas”) of each slice across the persistent storage of multiple nodes of the shared-nothing database system. When the data for a table is distributed among the nodes of a shared-nothing system in this manner, requests to read data from a particular row of the table may be handled by any node that stores a duplica of the slice to which the row is assigned. For each slice, a single duplica of the slice is designated as the “primary duplica”. All DML operations (e.g. inserts, deletes, updates, etc.) that target a particular row of the table are performed by the node that has the primary duplica of the slice to which the particular row is assigned. The changes made by the DML operations are then propagated from the primary duplica to the other duplicas (“secondary duplicas”) of the same slice.

Abstract: A shared-nothing database system is provided in which parallelism and workload balancing are increased by assigning the rows of each table to “slices”, and storing multiple copies (“duplicas”) of each slice across the persistent storage of multiple nodes of the shared-nothing database system. When the data for a table is distributed among the nodes of a shared-nothing system in this manner, requests to read data from a particular row of the table may be handled by any node that stores a duplica of the slice to which the row is assigned. For each slice, a single duplica of the slice is designated as the “primary duplica”. All DML operations (e.g. inserts, deletes, updates, etc.) that target a particular row of the table are performed by the node that has the primary duplica of the slice to which the particular row is assigned. The changes made by the DML operations are then propagated from the primary duplica to the other duplicas (“secondary duplicas”) of the same slice.

Abstract: Techniques are introduced herein for maintaining geometry-type data on persistent storage and in memory. Specifically, a DBMS that maintains a database table, which includes at least one column storing spatial data objects (SDOs), also maintains metadata for the database table that includes definition data for one or more virtual columns of the table. According to an embodiment, the definition data includes one or more expressions that calculate minimum bounding box values for SDOs stored in the geometry-type column in the table. The one or more expressions in the metadata maintained for the table are used to create one or more in-memory columns that materialize the bounding box data for the represented SDOs. When a query that uses spatial-type operators to perform spatial filtering over data in the geometry-type column is received, the DBMS replaces the spatial-type operators with operators that operate over the scalar bounding box information materialized in memory.

Abstract: A manager file system (MFS) runs as a user space file system. The MFS, implemented using an OS process, exposes a mount point as a communication endpoint to the single process. Mounting, unmounting, and changing configuration of individual database file systems (DBFSs) are done by overloading extended attributes on the mount point. The MFS services all DBFSs mounted at different mount points registered to the single process of the MFS and ensures optimal resource utilization among the DBFSs in the single process while guaranteeing resource isolation.

Abstract: A manager file system (MFS), implemented using an OS process, exposes a path in the native file system as the root of its file system (e.g., mount point). The MFS informs the OS kernel that any file system operation whose path contains the mount point as its prefix, should be handed over to the process by invoking an appropriate interface method that the process implements as part of its file system implementation. The MFS manages one or more applications and leverages the authentication mechanism of the OS to provide fined-grained access control of MFS managed applications.

Abstract: A manager file system (MFS) runs as a user space file system. The MFS, implemented using an OS process, exposes a mount point as a communication endpoint to the single process. Mounting, unmounting, and changing configuration of individual database file systems (DBFSs) are done by overloading extended attributes on the mount point. The MFS services all DBFSs mounted at different mount points registered to the single process of the MFS and ensures optimal resource utilization among the DBFSs in the single process while guaranteeing resource isolation. Multiple MFSs may be created to manage sets of DBFSs.

Abstract: A shared-nothing database system is provided in which parallelism and workload balancing are increased by assigning the rows of each table to “slices”, and storing multiple copies (“duplicas”) of each slice across the persistent storage of multiple nodes of the shared-nothing database system. When the data for a table is distributed among the nodes of a shared-nothing system in this manner, requests to read data from a particular row of the table may be handled by any node that stores a duplica of the slice to which the row is assigned. For each slice, a single duplica of the slice is designated as the “primary duplica”. All DML operations (e.g. inserts, deletes, updates, etc.) that target a particular row of the table are performed by the node that has the primary duplica of the slice to which the particular row is assigned. The changes made by the DML operations are then propagated from the primary duplica to the other duplicas (“secondary duplicas”) of the same slice.

Abstract: Techniques are described for materializing computations in memory. In an embodiment, responsive to a database server instance receiving a query, the database server instance identifies a set of computations for evaluation during execution of the query. Responsive to identifying the set of computations, the database server instance evaluates at least one computation in the set of computations to obtain a first set of computation results for a first computation in the set of computations. After evaluating the at least one computation, the database server instance stores, within an in-memory unit, the first set of computation results. The database server also stores mapping data that maps a set of metadata values associated with the first computation to the first set of computation results.

Abstract: A “hybrid derived cache” stores semi-structured data or unstructured text data in an in-memory mirrored form and columns in another form, such as column-major format. The hybrid derived cache may cache scalar type columns in column-major format. The structure of the in-memory mirrored form of semi-structured data or unstructured text data enables and/or enhances access to perform path-based and/or text based query operations. A hybrid derived cache improves cache containment for executing query operations. The in-memory mirrored form is used to compute queries in a transactionally consistent manner through the use of an invalid vector that used to determine when to retrieve the transactionally consistent persistent form of semi-structured data or unstructured text data in lieu of the in-memory form.