US 2014/0279849 A1 · HIERARCHICAL TABLESPACE SPACE MANAGEMENT

Abstract

A method, apparatus, and system for hierarchical organization of tablespace free space metadata in a database are provided. The hierarchy is divided into at least two levels: level 1 or L1 bitmap blocks are stored as a shared data structure and map free space in a tablespace, whereas level 2 or L2 bitmap blocks are stored as separate local copies at each database instance and map to the L1 bitmap blocks. This hierarchical organization provides a mechanism for finer grained concurrency control, enabling highly parallel tablespace metadata processing to accommodate the performance requirements of large tablespaces with big data sets. By integrating the hierarchical organization as part of the tablespace stack layer in a database management system (DBMS), implementations can be provided transparently to database end users without demanding any additional administrative, maintenance, or development burdens.

Claims20

Dependent claims

A method, comprising steps of:

storing tablespace metadata describing a tablespace of a database;
receiving, at a first instance of a plurality of database server instances for the database, a request to perform an operation on the tablespace;
updating the tablespace metadata according to the operation;
wherein the tablespace metadata is organized by a hierarchy comprising:
a level 1 (L1) bitmap block level comprising a plurality of L1 bitmap blocks mapping free space of a plurality of allocation units in the tablespace, wherein each of the plurality of L1 bitmap blocks indicates an ownership affinity with one of the plurality of database server instances, and wherein the L1 bitmap block level is stored as a single copy shared by the plurality of database server instances;
a level 2 (L2) bitmap block level comprising a plurality of L2 bitmap blocks mapping to the L1 bitmap block level, wherein each of the plurality of database server instances is assigned to store one of the plurality of L2 bitmap blocks;
wherein the method is performed by one or more computing devices.

4 more elements

A non-transitory computer-readable medium storing one or more sequences of instructions which, when executed by one or more processors, cause performing of:

storing tablespace metadata describing a tablespace of a database;
receiving, at a first instance of a plurality of database server instances for the database, a request to perform an operation on the tablespace;
updating the tablespace metadata according to the operation;
wherein the tablespace metadata is organized by a hierarchy comprising:
a level 1 (L1) bitmap block level comprising a plurality of L1 bitmap blocks mapping free space of a plurality of allocation units in the tablespace, wherein each of the plurality of L1 bitmap blocks indicates an ownership affinity with one of the plurality of database server instances, and wherein the L1 bitmap block level is stored as a single copy shared by the plurality of database server instances;
a level 2 (L2) bitmap block level comprising a plurality of L2 bitmap blocks mapping to the L1 bitmap block level, wherein each of the plurality of database server instances is assigned to store one of the plurality of L2 bitmap blocks.

3 more elements

A database management system comprising one or more computing devices configured to:

store tablespace metadata describing a tablespace of a database;
receive, at a first instance of a plurality of database server instances for the database, a request to perform an operation on the tablespace;
update, by a tablespace stack layer, the tablespace metadata according to the operation;
wherein the tablespace metadata is organized by a hierarchy comprising:
a level 1 (L1) bitmap block level comprising a plurality of L1 bitmap blocks mapping free space of a plurality of allocation units in the tablespace, wherein each of the plurality of L1 bitmap blocks indicates an ownership affinity with one of the plurality of database server instances, and wherein the L1 bitmap block level is stored as a single copy shared by the plurality of database server instances;
a level 2 (L2) bitmap block level comprising a plurality of L2 bitmap blocks mapping to the L1 bitmap block level, wherein each of the plurality of database server instances is assigned to store one of the plurality of L2 bitmap blocks.

3 more elements

Dependencies are inferred from the claim text.

Hierarchical tablespace space management

Life of this patent

Hierarchical tablespace space management

Life of this patent

Abstract

Claims20