Abstract: In one aspect, a computerized method for managing tombstones in a node of a Distributed Database Base System (DDBS) includes the step of providing a rule that, for a namespace in a record of the node of the DDBS that allows expiration, mandates that a later generation's expiration time of the namespace never decreases. The computerized method includes the step of determining that an administrator of the DDBS has set an expiration time of the namespace to infinity. The computerized method includes the step of implementing a background process of the DDBS, wherein the background process scans a DDBS node's drive and flags a set of extant tombstones that are no longer covering viable namespaces or viable records. The computerized method includes the step of deleting all the flagged tombstones.

Abstract: In one aspect, a computerized method useful for operating a database management system DMBS DBMS in a strong consistency mode comprising includes the step of implementing an atomic transfer of a master node of the DMBS DBMS. The method includes the step of implementing a master node restriction, wherein the master node restriction guarantees no more than one master node is ever available. The information about a set of nodes participating in a cluster of the set node of the DMBS DBMS is maintained to allow a subset of nodes to determine that the one master node is a master of a subset of data stored in the cluster.

Abstract: In one aspect, a computerized method for managing consistency and availability tradeoffs in a real-time operational database management system (DBMS) includes the step of implementing consistency in an AP mode of the real-time operational DBMS by implementing the following steps. The method adds a set of schemes that enable a real-time operational DBMS to linearize read/write operations in all situations except a first specified situation and a second specified situation. The real-time operational DBMS is in AP mode, at least one master node for every data item is available in the database cluster of the real-time operational DBMS at all times. The method implements a CP mode of operation.

Abstract: A computer-implemented method of a distributed database system includes generating a database index. The method includes mapping a first specified number of bits of the database index to a database key. The method includes mapping a second specified number of bits to a data object associated with the database key. The method includes storing the first specified number of bits of the database key in a dram memory. The method includes storing second specified number of bits with the data object in a solid-state device (SSD) storage.

Abstract: in one aspect, a computerized method for managing consistency and availability tradeoffs in a real-time operational database management system (DBMS) includes the step of implementing consistency in an AP mode of the real-time operational DBMS by implementing the following steps. The method adds a set of schemes that enable a real-time operational DBMS to linearize read/write operations in all situations except a first specified situation and a second specified situation. The real-time operational DBMS is in AP mode, at least one master node for every data item is available in the database cluster of the real-time operational DBMS at all times. The method implements a CP mode of operation.

Abstract: In one aspect, a computerized method useful for operating a database management system DMBS in a strong consistency mode comprising includes the step of implementing an atomic transfer of a master node of the DMBS. The method includes the step of implementing a master node restriction, wherein the master node restriction guarantees no more than one master node is ever available. The information about a set of nodes participating in a cluster of the set node of the DMBS is maintained to allow a subset of nodes to determine that the one master node is a master of a subset of data stored in the cluster. The method includes the step of implementing a hybrid clock in the DBMS. The method includes the step of implementing a replication integrity policy. The replication integrity policy guarantees a strict consistency between the set of nodes and maintains replication integrity using a redo mechanism to ensure that no read operations or write operations are allowed when replicas are in an unknown state.

Abstract: In one aspect, a computerized method for managing tombstones in a node of a Distributed Database Base System (DDBS) includes the step of providing a rule that, for a namespace in a record of the node of the DDBS that allows expiration, mandates that a later generation's expiration time of the namespace never decreases. The computerized method includes the step of determining that an administrator of the DDBS has set an expiration time of the namespace to infinity. The computerized method includes the step of implementing a background process of the DDBS, wherein the background process scans a DDBS node's drive and flags a set of extant tombstones that are no longer covering viable namespaces or viable records. The computerized method includes the step of deleting all the flagged tombstones.

Abstract: In one exemplary embodiment, a method includes allocating an arena block of a shared memory of a database node server. The arena block is divided into one or more slots. The one or more slots include a discreet and constant area of memory within the arena block. Each slot is assigned a constant-memory address relative to an arena-block's shared memory address. The index is implemented as a red-black tree data structure. Each red-black tree node is mapped to a slot. Each red-black-tree node is provided a pointer to one or more neighbor nodes. The index stored in shared memory can be used during a ‘warm’ rebooting process.

Abstract: A computer-implemented method of a distributed database system includes generating a database index. The method includes mapping a first specified number of bits of the database index to a database key. The method includes mapping a second specified number of bits to a data object associated with the database key. The method includes storing the first specified number of bits of the database key in a dram memory. The method includes storing second specified number of bits with the data object in a solid-state device (SSD) storage.

Abstract: In one exemplary embodiment, a method includes allocating an arena block of a shared memory of a database node server. The arena block is divided into one or more slots. The one or more slots include a discreet and constant area of memory within the arena block. Each slot is assigned a constant-memory address relative to an arena-block's shared memory address. The index is implemented as a red-black tree data structure. Each red-black tree node is mapped to a slot. Each red-black-tree node is provided a pointer to one or more neighbor nodes. The index stored in shared memory can be used during a ‘warm’ rebooting process.