Core in-memory space and object management architecture in a traditional RDBMS supporting DW and OLTP applications

A method comprising:

• maintaining, within an area in volatile memory that is accessible to a database server, a set of in-memory objects;
• wherein each respective in-memory object within the set of in-memory objects includes a set of one or more in-memory segments;
• wherein each respective in-memory segment in the set of one or more in-memory segments includes a set of in-memory extents;
• wherein each respective in-memory extent in the set of in-memory extents is a contiguous chunk of memory from the area in volatile memory that is accessible to the database server;
• and
• maintaining a plurality of pools of in-memory extents in the area in volatile memory, including a first pool and a second pool;
• wherein, within each pool of the plurality of pools, all in-memory extents have a same fixed size;
• wherein in-memory extents of the first pool differ in size from in-memory extents of the second pool.

A method comprising:

• maintaining, within an area in volatile memory that is accessible to a database server, a set of in-memory objects;
• wherein each respective in-memory object within the set of in-memory objects:
• is a table or a partition of a table, and
• includes a set of one or more in-memory segments;
• wherein each respective in-memory segment in the set of one or more in-memory segments includes a set of in-memory extents;
• wherein each respective in-memory extent in the set of in-memory extents is a contiguous chunk of memory from the area in volatile memory that is accessible to the database server;
• and
• wherein each in-memory segment in the set of one or more in-memory segments:
• corresponds to and contains the same data as a respective on-disk segment;
• and
• stores, in a mirror format, the data that the respective on-disk segment stores in a persistent format;
• wherein the mirror format is different from the persistent format.

A method comprising:

• maintaining, within an area in volatile memory that is accessible to a database server, a set of in-memory objects;
• wherein each respective in-memory object within the set of in-memory objects includes a set of one or more in-memory segments;
• wherein each respective in-memory segment in the set of one or more in-memory segments includes a set of in-memory extents;
• wherein each respective in-memory extent in the set of in-memory extents is a contiguous chunk of memory from the area in volatile memory that is accessible to the database server;
• and
• determining that an on-disk segment that corresponds to a particular in-memory segment of the set of one or more in-memory segments has changed;
• in response to determining that the on-disk segment has changed:
• dropping the particular in-memory segment from the area in volatile memory;
• re-allocating space from the area in volatile memory to generate a new in-memory segment corresponding to the on-disk segment;
• and
• loading the new in-memory segment with data from the on-disk segment.

One or more non-transitory storage media storing instructions which, when executed by one or more processors, cause performance of:

• maintaining, within an area in volatile memory that is accessible to a database server, a set of in-memory objects;
• wherein each respective in-memory object within the set of in-memory objects includes a set of one or more in-memory segments;
• wherein each respective in-memory segment in the set of one or more in-memory segments includes a set of in-memory extents;
• wherein each respective in-memory extent in the set of in-memory extents is a contiguous chunk of memory from the area in volatile memory that is accessible to the database server;
• and
• maintaining, within the area in volatile memory that is accessible to the database server, a set of stripe lists;
• wherein each respective stripe list in the set of stripe lists includes a set of stripes;
• wherein each respective stripe in the set of stripes includes a contiguous chunk of in-memory extents.

One or more non-transitory storage media, storing instructions which, when executed by one or more processors, cause performance of:

• maintaining, within an area in volatile memory that is accessible to a database server, a set of in-memory objects;
• wherein each respective in-memory object within the set of in-memory objects includes a set of one or more in-memory segments;
• wherein each respective in-memory segment in the set of one or more in-memory segments includes a set of in-memory extents;
• wherein each respective in-memory extent in the set of in-memory extents is a contiguous chunk of memory from the area in volatile memory that is accessible to the database server;
• and
• maintaining a plurality of pools of in-memory extents in the area in volatile memory, including a first pool and a second pool;
• wherein, within each pool of the plurality of pools, all in-memory extents have a same fixed size;
• wherein in-memory extents of the first pool differ in size from in-memory extents of the second pool.

One or more non-transitory storage media storing instructions which, when executed by one or more processors, cause performance of:

• maintaining, within an area in volatile memory that is accessible to a database server, a set of in-memory objects;
• wherein each respective in-memory object within the set of in-memory objects:
• is a table or a partition of a table, and
• includes a set of one or more in-memory segments;
• wherein each respective in-memory segment in the set of one or more in-memory segments includes a set of in-memory extents;
• wherein each respective in-memory extent in the set of in-memory extents is a contiguous chunk of memory from the area in volatile memory that is accessible to the database server;
• and
• wherein each in-memory segment in the set of one or more in-memory segments:
• corresponds to and contains the same data as a respective on-disk segment;
• and
• stores, in a mirror format, the data that the respective on-disk segment stores in a persistent format;
• wherein the mirror format is different from the persistent format.

One or more non-transitory storage media storing instructions which, when executed by one or more processors, cause performance of:

• maintaining, within an area in volatile memory that is accessible to a database server, a set of in-memory objects;
• wherein each respective in-memory object within the set of in-memory objects includes a set of one or more in-memory segments;
• wherein each respective in-memory segment in the set of one or more in-memory segments includes a set of in-memory extents;
• wherein each respective in-memory extent in the set of in-memory extents is a contiguous chunk of memory from the area in volatile memory that is accessible to the database server;
• and
• determining that an on-disk segment that corresponds to a particular in-memory segment of the set of one or more in-memory segments has changed;
• in response to determining that the on-disk segment has changed:
• dropping the particular in-memory segment from the area in volatile memory;
• re-allocating space from the area in volatile memory to generate a new in-memory segment corresponding to the on-disk segment;
• and
• loading the new in-memory segment with data from the on-disk segment.