Write operations

With data sharing, Db2 usually writes changed data to the group buffer pool before writing that changed data to disk.

How the GBPCACHE option affects write operations
You can use several options in a CREATE TABLESPACE statement to tell Db2 how you want data to be handled through the group buffer pool.
How Db2 writes to the group buffer pool
With data sharing, Db2 still performs deferred writes for Db2 table spaces, indexes or partitions. However, when an update is to a page set that has inter-Db2 read/write interest, Db2 forces the updated pages to the group buffer pool before or when the transaction commits.
How Db2 writes from the group buffer pool to disk
The process of writing pages from the group buffer pool to disk is called castout.
Group buffer pool checkpoint
When a group buffer pool is damaged, all changed data that belong to GBP-dependent page sets must be recovered to the page sets from the Db2 logs.

Parent topic: Tuning group buffer pools