“The In-Memory Column Store (IM column store) is an optional portion of the system global area (SGA) that stores copies of tables, table partitions, and other database objects. In the IM column store, data is populated by column rather than row as it is in other parts of the SGA, and data is optimized for rapid scans. The IM column store is included with the Oracle Database In-Memory option.”
- Configure the database to use IM Column Store; (https://www.techdatabasket.com/enabling-oracle-database-in-memory-database-in-memory-option-in-oracle-database-12c-release-1/)
- Setup some tables to use the IM Column Store; (https://www.techdatabasket.com/enabling-and-disabling-table-for-the-im-column-store-in-oracle-12c/)
- Datapump from one database to another in order to use IM Column Store. (https://www.techdatabasket.com/using-datapump-utility-to-import-tables-with-in-memory-column-store-in-oracle-12c/)
VIEWS and SQL key statements:
- V$IM_SEGMENTS
- USER_TABLES
- DBA_DIRECTORIES
- SELECT OWNER, SEGMENT_NAME, INMEMORY_PRIORITY, INMEMORY_COMPRESSION
FROM V$IM_SEGMENTS; - “In-Memory FastStart (IM FastStart) reduces the time to populate data into the IM column store when a database instance restarts.”
- “You can import database objects that are enabled for the IM column store using the TRANSFORM=INMEMORY:y option of the impdp command. “
Automatic Big Table Caching
“In Oracle Real Application Clusters (Oracle RAC) environments, this feature is supported only with parallel queries. In single instance environments, this feature is supported with both parallel and serial queries.”
“The DB_BIG_TABLE_CACHE_PERCENT_TARGET parameter determines the percentage of the buffer cache size used for scans. “
“The DB_BIG_TABLE_CACHE_PERCENT_TARGET parameter is only enabled in an Oracle RAC environment if PARALLEL_DEGREE_POLICY is set to AUTO or ADAPTIVE. “
Views:
- V$BT_SCAN_CACHE
- V$BT_SCAN_OBJ_TEMPS
Data Warehousing and Business Intelligence -> Database VLDB and Partitioning Guide -> Automatic Big Table Caching
Oracle Database Administrator’s Guide -> Managing Memory -> 6.7 Using the In-Memory Column Store
Database SQL Language Reference -> CREATE DIRECTORY
*The views expressed here are my own and do not represent those of my employer.*
Hello, I’m Bruno — a dual citizen of Brazil and Sweden. I bring a global perspective shaped by experiences in both South America and Europe, with a strong focus on collaboration and innovation across cultures. I am a Computer Scientist, PhD Candidate in Information and Communication Technologies, focusing on Data Science and Artificial Intelligence, and hold dual Master’s degrees in Data Science and Cybersecurity. With over fifteen years of international experience spanning Brazil, Hungary, and Sweden, I have collaborated with global organizations such as IBM, Playtech, and Oracle, as well as contributed remotely to projects across multiple regions. My professional interests include Databases, Cybersecurity, Cloud Computing, Data Science, Data Engineering, Big Data, Artificial Intelligence, Programming, and Software Engineering, all driven by a deep passion for transforming data into strategic business value.