Abstract: In accordance with an embodiment, described herein is a system and method for use of immutable accessors with dynamic byte arrays. In accordance with an embodiment, a database driver provides access by software applications executing at an application server to data at a database, including associating a result set cache manager with a pool of result set caches. Each result set cache can be associated with one or more immutable accessors. In response to receiving a request from an application, to access a set of data, the set of data from the database is received into a particular result set cache. In response to receiving a subsequent request for a same set of data, from a same or another application using a same or another database connection, access is provided to the immutable accessor associated with the particular result set cache, for use in accessing the data therein.

Abstract: Described herein are systems and methods for providing access to a database in a multi-tenant environment, including the use of a connection pool, and support for live addition of a tenant. When a pluggable database (PDB), for use by a tenant, is added to a multi-tenant database, it can generate an event to notify the connection pool. The connection pool environment consumes this PDB-add event, and dynamically configures a new tenant to access the shared pool. Since the new tenant addition is based on receipt of an event from the database, the connection pool does not require manual configuration for that tenant. Once a tenant is added, it can borrow connections from the pool in the same manner as existing tenants, and can also share existing pool properties, such as, for example a maximum pool size, or maximum number of connections per tenant.

Abstract: In accordance with an embodiment, described herein is a system and method for high availability and load balancing in a database environment. A transparency engine can be provided between client applications and a database, and can operate as a proxy engine for the database and as a session abstraction layer for the client applications, to enable the client applications to utilize database features provided by the connection pool without code changes to the client applications. The transparency can keep track of session states, request boundaries and cursors to efficiently reuse the database connections across the client applications. The transparency engine can use the request boundaries and indicators from the database to detect safe places to drain database connections in the event of database outages.

Abstract: Described is a system, method, and computer program product is provided that implements high-volume data ingestion in a relational database system. A middle-tier structure is provided that sits between the IoT data producers and the back-end database system. Data records are gathered together and organized at the middle tier, and groups of those records are ingested on a group-basis into the database in a manner which bypasses standard SQL engine processing.

Abstract: In accordance with an embodiment, the system enables access to a sharded database using a cache and a shard topology. A shard-aware client application connecting to a sharded database can use a connection pool (e.g., a Universal Connection Pool, UCP), to store or access connections to different shards or chunks of the sharded database within a shared pool. As new connections are created, a shard topology layer can be built at the database driver layer, which learns and caches shard key ranges to locations of shards. The shard topology layer enables subsequent connection requests from a client application to use a fast key path access to the appropriate shard or chunk.

Abstract: In accordance with an embodiment, the system enables access to a sharded database using a cache and a shard topology. A shard-aware client application connecting to a sharded database can use a connection pool (e.g., a Universal Connection Pool, UCP), to store or access connections to different shards or chunks of the sharded database within a shared pool. As new connections are created, a shard topology layer can be built at the database driver layer, which learns and caches shard key ranges to locations of shards. The shard topology layer enables subsequent connection requests from a client application to use a fast key path access to the appropriate shard or chunk.

Abstract: A system and method is described for database split generation in a massively parallel or distributed database environment including a plurality of databases and a data warehouse layer providing data summarization and querying functionality. A database table accessor of the system obtains, from an associated client application, a query for data in a table of the data warehouse layer, wherein the query includes a user preference. The system obtains table data representative of properties of the table, and determines a splits generator in accordance with one or more of the user preference or the properties of the table. The system generates, by the selected splits generator, table splits dividing the user query into a plurality of query splits, and outputs the plurality of query splits to an associated plurality of mappers for execution by the associated plurality of mappers of each of the plurality of query splits against the table.

Abstract: Techniques are provided for creating, organizing, and maintaining a sharded database. A sharded database can be created using user-defined sharding, system-managed sharding, or composite sharding. The sharded database is implemented with relational database techniques. The techniques described can be used to route database requests and process queries in a sharded database.

Abstract: Techniques are provided for creating, organizing, and maintaining a sharded database. A sharded database can be created using user-defined sharding, system-managed sharding, or composite sharding. The sharded database is implemented with relational database techniques. The techniques described can be used to route database requests and process queries in a sharded database.

Abstract: A system and method for reducing communications overhead in a distributed transaction processing environment such as an XA environment. In accordance with an embodiment communication overhead is reduced in a transaction by deferring a transaction end communication. The deferred transaction end communication is determined from a subsequent XA transaction communication thereby reducing the number of networks calls required for each transaction and enhancing system performance.

Abstract: In accordance with an embodiment, described herein is a system and method for use of a non-blocking process with a resource pool, for example a connection pool, or another type of computing environment. A generic wait-free approach can be used with a variety of different types of resource pools and pool elements. Threads which require access to a collection of resources do not have to wait for a lock on that collection of resources to become available. Although a borrowing thread may still be required to wait for a particular resource to be released, the wait-free approach allows the thread to browse through a list of available resources. The approach can be used with connection pools, or with other types of computing environments, to provide improved scalability in such systems.

Abstract: In accordance with an embodiment, described herein is a system and method for connection concentration in a database environment. A transparency engine provided between client applications and a database can include a connection pool (e.g., UCP connection pool). The transparency engine can operate as a proxy engine for the database and as a session abstraction layer for the client applications, to enable the client applications to utilize features provided by the connection pool without code changes. The transparency engine can receive application connections from the client applications, and concentrate the application connections on a smaller number of database connections maintained in the connection pool.

Abstract: In accordance with an embodiment, described herein is a system and method for high availability and load balancing in a database environment. A transparency engine can be provided between client applications and a database, and can operate as a proxy engine for the database and as a session abstraction layer for the client applications, to enable the client applications to utilize database features provided by the connection pool without code changes to the client applications. The transparency can keep track of session states, request boundaries and cursors to efficiently reuse the database connections across the client applications. The transparency engine can use the request boundaries and indicators from the database to detect safe places to drain database connections in the event of database outages.

Abstract: In accordance with an embodiment, described herein is a system and method for row buffering in a database environment. A transparency engine can be provided between client applications and a database, and can operate as a proxy engine for the database and as a session abstraction layer for the client applications, to enable the client applications to utilize database features provided by the connection pool without code changes to the client applications. The transparency engine can maintain a plurality of local row buffers to store rows fetched from a database. The local buffers can be filled by rows pre-fetched from the database. When a client application requests rows from the database, the transparency engine can first check whether the rows exist in a local buffer. If the rows are present in the local buffer, the transparency engine sends the rows to the requesting client application, without going to the database.

Abstract: A system and method is described for database split generation in a massively parallel or distributed database environment including a plurality of databases and a data warehouse layer providing data summarization and querying functionality. A database table accessor of the system obtains, from an associated client application, a query for data in a table of the data warehouse layer, wherein the query includes a user preference. The system obtains table data representative of properties of the table, and determines a splits generator in accordance with one or more of the user preference or the properties of the table. The system generates, by the selected splits generator, table splits dividing the user query into a plurality of query splits, and outputs the plurality of query splits to an associated plurality of mappers for execution by the associated plurality of mappers of each of the plurality of query splits against the table.

Abstract: In accordance with an embodiment, a system enables multidimensional search within a resource pool, to support complex borrow operations such as, for example, specifying ranges for particular connection properties. As threads access the pool, attempting to borrow connections having particular connection properties, one or more skipped pool elements can be represented as skip lists within a k-dimensional tree (KD-tree) or other data structure that enables searching across multiple dimensions. In response to receiving a request to borrow a connection having particular connection properties, a multidimensional search can be performed within the KD-tree to determine the availability of a connection having the requested properties.

Abstract: A system and method for reducing communications overhead in a distributed transaction processing environment such as an XA environment. In accordance with an embodiment communication overhead is reduced in a transaction start method by deferring a transaction start communication. The deferred transaction start communication is determined from a subsequent transaction processing communication thereby reducing the number of networks calls required for each transaction and enhancing system performance.

Abstract: Techniques are described for closing one or more connections with a database management system (DBMS) as part of a planned operation such as maintenance and load balancing. In an embodiment, a request is received for a planned operation of a database server of a DBMS that requires releasing and migrating database sessions. Over a database connection with the database server, the DBMS or a Client-Driver on the client system that interfaces with the DBMS, may receive request(s) from the client system. Based on the request(s), a safe point, for the database connection with the database server, at which the database connection of the client system with the database server can be closed without affecting the success of execution of next one or more command that the client system intended to request the DBMS to execute on the database server, is determined.

Abstract: Described herein are systems and methods for providing access to a database in a multi-tenant environment, including the use of a connection pool, and support for server-side connection pool multiple tagging. For example, the system can provide a capability to associate multiple connection properties with a particular server-side connection in, e.g., an Oracle Database Resident Connection Pooling (DRCP) environment; look up a connection with one or multiple properties; and provide information about a returned connection so that a requesting application can review the properties associated with the returned connection, in order to determine how best to “fix-up” or otherwise use that connection.

Abstract: Described herein are systems and methods for providing access to a database in a multi-tenant environment, including the use of a connection pool, and support for limiting the maximum number of connections per tenant or per database shard. For example, when a tenant is associated with a service, configuring a maximum connections per service limit on a shared connection pool indicates to the system that the shared pool should not repurpose existing connections, or create new connections for a service, if the maximum connections per service limit has been reached for that particular service. The system can also maintain a parameter that keeps track of the total number of connections created to each shard of a sharded database. The connection pool can scan the sharded database topology, to determine which shard or sharded instance can satisfy the request, without exceeding the maximum limit for that shard.