Abstract: Techniques are disclosed herein for identifying, recording and restoring the state of a database session and various aspects thereof. A session template data structure is generated that includes session attribute values describing various aspects of the session that is established between a client system and a database management system (DBMS and enables the client system to issue to the DBMS commands for execution. Based on the session attribute values, DBMS may generate a template identifier corresponding to the session template data structure. The template identifier may be stored in an association with the session state that it partially (or in whole) represents. In an embodiment, when another state of a session is captured, if the template identifier for the state is the same, then rather than storing the attribute-value pairs for the other state, the template identifier is further associated with the other state.

Abstract: Instances of a database server can be of two kinds, regular or mirage that respectively handle database requests in sessions behaving normally or abnormally, and based on changes in behavior, sessions are relocated therebetween. Behavior of sessions is evaluated based on statistics generated in processing requests in individual steps within one or more stages, such as parse stage. The evaluation may be automatically tuned by changing tests that are enabled based on priorities, changing thresholds within tests, changing whether sessions are evaluated together as a group, and changing periodicity of evaluation. Evaluation may be triggered by news of normal/abnormal activity in locations of sessions' origin. Mirage instances can be of multiple classes, execute in lower/higher capacity computers. Sessions may start in either kind of instance. Sessions may be relocated for reasons unrelated to maliciousness, such as excessive utilization of resources, excessive errors, or update of software of the database server.

Abstract: Techniques are described herein for isolating a network stack in a multitenant container DBMS. A first and second pluggable database are established within a container database. A first network stack is assigned to the first pluggable database and a second network stack is assigned to the second pluggable database. A request is received to connect to the first pluggable database and a connection is established to the first pluggable database using the first network stack. A request is received to connect to the second pluggable database and a connection is established to the second pluggable database using the second network stack.

Abstract: Techniques are described herein for intelligent pooling and management of isolated hierarchical runtimes in a multi-tenant environment. In an embodiment, an allocation of operating system resources of a container database management system (CDBMS) is allocated to each generic nest of a pool of generic nests. The allocation includes a quota of one or more processors and a quota of memory. A configuration profile for a PDB in the CDBMS is then determined. Based on the configuration profile determined for the PDB, a matching generic nest from the pool of generic nests is determined. A matching generic nest is assigned to the PDB. The matching generic nest is then configured for the PDB.

Abstract: Techniques are described herein for isolating runtime environments in a multitenant container DBMS. A CDB may contain a database dictionary that defines a plurality of pluggable databases and a respective database nest for each pluggable database. Each respective database nest of said each pluggable database is associated with different operating system privileges. When database sessions are established on a container DBMS, each database session is given access to a pluggable database by attaching the respective database nest of the pluggable database to each database session.

Abstract: Techniques are described herein for isolating runtime environments in a multitenant container DBMS. A CDB may contain a database dictionary that defines a plurality of pluggable databases and a respective database nest for each pluggable database. Each respective database nest of said each pluggable database is associated with different operating system privileges. When database sessions are established on a container DBMS, each database session is given access to a pluggable database by attaching the respective database nest of the pluggable database to each database session.

Abstract: Techniques are described herein for intelligent pooling and management of isolated hierarchical runtimes in a multi-tenant environment. In an embodiment, an allocation of operating system resources of a container database management system (CDBMS) is allocated to each generic nest of a pool of generic nests. The allocation includes a quota of one or more processors and a quota of memory. A configuration profile for a PDB in the CDBMS is then determined. Based on the configuration profile determined for the PDB, a matching generic nest from the pool of generic nests is determined. A matching generic nest is assigned to the PDB. The matching generic nest is then configured for the PDB.

Abstract: Techniques are described herein for isolating a network stack in a multitenant container DBMS. A first and second pluggable database are established within a container database. A first network stack is assigned to the first pluggable database and a second network stack is assigned to the second pluggable database. A request is received to connect to the first pluggable database and a connection is established to the first pluggable database using the first network stack. A request is received to connect to the second pluggable database and a connection is established to the second pluggable database using the second network stack.

Abstract: Techniques are disclosed herein for identifying, recording and restoring the state of a database session and various aspects thereof. A session template data structure is generated that includes session attribute values describing various aspects of the session that is established between a client system and a database management system (DBMS and enables the client system to issue to the DBMS commands for execution. Based on the session attribute values, DBMS may generate a template identifier corresponding to the session template data structure. The template identifier may be stored in an association with the session state that it partially (or in whole) represents. In an embodiment, when another state of a session is captured, if the template identifier for the state is the same, then rather than storing the attribute-value pairs for the other state, the template identifier is further associated with the other state.

Abstract: Techniques are disclosed herein for identifying, recording and restoring the state of a database session and various aspects thereof. A session template data structure is generated that includes session attribute values describing various aspects of the session that is established between a client system and a database management system (DBMS and enables the client system to issue to the DBMS commands for execution. Based on the session attribute values, DBMS may generate a template identifier corresponding to the session template data structure. The template identifier may be stored in an association with the session state that it partially (or in whole) represents. In an embodiment, when another state of a session is captured, if the template identifier for the state is the same, then rather than storing the attribute-value pairs for the other state, the template identifier is further associated with the other state.

Abstract: A method for memory quarantine comprises: in response to a memory error, determining an extent associated with the memory error, wherein the extent defines an amount of memory comprising a plurality of chunks; traversing, forward from a beginning chunk of the plurality chunks, the plurality of chunks until a first chunk is determined to be corrupt; traversing, in reverse from a last chunk of the plurality of chunks, the plurality of chunks until a second chunk is determine to be corrupt; flagging a subset of the plurality of chunks as quarantined, wherein the subset begins with the first chunk and ends with the second chunk, and wherein quarantine prevents the subset from being reallocated after being released.

Abstract: A method for memory quarantine comprises: in response to a memory error, determining an extent associated with the memory error, wherein the extent defines an amount of memory comprising a plurality of chunks; traversing, forward from a beginning chunk of the plurality chunks, the plurality of chunks until a first chunk is determined to be corrupt; traversing, in reverse from a last chunk of the plurality of chunks, the plurality of chunks until a second chunk is determine to be corrupt; flagging a subset of the plurality of chunks as quarantined, wherein the subset begins with the first chunk and ends with the second chunk, and wherein quarantine prevents the subset from being reallocated after being released.

Abstract: A server side connection pool provides pooling of server connections. Thus, client side processes do not create groups of dedicated resources. Clients are provided the capability to communicate to a server side connection broker process to GET a pooled server connection comprising connection state plus a thread of execution for doing some work, whereby requesting the work can bypass the connection broker process and go directly to the assigned pooled connection. Once the client issues a RELEASE to release the pooled connection back to the pool, a completely different client process on potentially a different client middle tier machine can reuse the same pooled connection. The server-side connection pool can be logically partitioned into sub-pools that correspond to connection classes that typically correspond to respective applications. A client process can request a pooled connection having a particular state, where a stored procedure can be executed to generate such state.

Abstract: A server side connection pool provides pooling of server connections. Thus, client side processes do not create groups of dedicated resources. Clients are provided the capability to communicate to a server side connection broker process to GET a pooled server connection comprising connection state plus a thread of execution for doing some work, whereby requesting the work can bypass the connection broker process and go directly to the assigned pooled connection. Once the client issues a RELEASE to release the pooled connection back to the pool, a completely different client process on potentially a different client middle tier machine can reuse the same pooled connection. The server-side connection pool can be logically partitioned into sub-pools that correspond to connection classes that typically correspond to respective applications. A client process can request a pooled connection having a particular state, where a stored procedure can be executed to generate such state.

Abstract: A computer system having a kernel for mapping virtual memory address space to physical memory address space. The computer system uses a method for performing an input/output operation. A physical memory buffer is registered with a subsystem, and the physical memory buffer is associated with a first virtual address, a size and a key. The physical memory buffer is dynamically associated with a second virtual address which is different from the first virtual address. As part of an application program an input/output operation is requested regarding the second virtual address. An application table is used to obtain the first virtual address, the key and the size. The first virtual address, the key and the size are supplied to the subsystem. The subsystem uses the first virtual address, the key and the size, to determine the physical memory buffer and performs an input/output operation using the physical memory buffer without intervention of the kernel.