[OracleDatabase12cNewFeature] In-MemoryColumn

The IMCS (columnar memory) feature is officially introduced In the latest version of Database12c, 12.1.0.2 released by Oracle. It is an option called In-MemoryDatabaseOption at the time of release. What is IMCS? Is it different from SAPHANA? IMCS is a new independent area in SGA, just like the well-known BufferCache or SharedPo

The IMCS (columnar Memory) feature is officially introduced In the latest version of Database 12c, 12.1.0.2 released by Oracle. It is the Option called In-Memory Database Option at the time of release. What is IMCS? Is it different from sap hana? IMCS is a new independent area in SGA, just like the well-known Buffer Cache or Shared Po

The IMCS (columnar Memory) feature is officially introduced In the latest version of Database 12c, 12.1.0.2 released by Oracle. It is the Option called In-Memory Database Option at the time of release.

What is IMCS? Is it different from sap hana?

IMCS is a new independent area in SGA. Like the well-known Buffer Cache or Shared Pool, IMCS is closer to the Buffer Cache, it is used to cache data in tables, table partitions, or materialized views. However, the data format cached in IMCS is not in the traditional row mode, instead, it is cached as a column. To put it simply, Oracle databases can cache row-type data or column-type data in the memory, but only one row-type data is stored on the disk, this is a distinct difference between Oracle IMCS and the sap hana, Sybase IQ, and other columnar memory databases.

Oracle always has only one row of data on the disk. You can append a column of data to the cache. Note that the term "additional" mentioned here means that all previous behaviors of the Oracle database have not changed and should be cached in the Buffer Cache (traditional row-based Cache) but if a table is set to a column-type Cache, Oracle will maintain an additional column-type data for the table, this data is stored In the new SGA region In-Memory Area. This data will only be stored in the memory. Once the database instance is restarted, the memory will be reloaded (according to different settings, it can be loaded immediately upon startup, can also be used for RELOAD ).

What Oracle needs to ensure is how to efficiently maintain updates and synchronization when a large number of DML is generated, especially in the RAC environment, oracle did not disclose