Oracle background memory Transaction Processing

Checkpoint Process: triggers the checkpoint, synchronizes data on the memory hard disk, writes the system change number to the control file and data file, and triggers the dbwr process to write the cached data to the database.

The lgwr process is released to write data in the log buffer into the log table. At the same time, the log group is switched to archive the logs.

Checkpoint triggering time: definitions of log group switchover, instance shutdown, manual issuance, and fast_start_mttr_target parameter control.

Transaction commit: When commit is used, online redo logs will be written, and the table locks and row locks occupied by the transaction will be released. The cache will separately wait for the checkpoint and write it to the hard disk.

Shared Pool function: parses SQL statements and generates execution plans (this is the characteristic of variable binding, so the execution plan does not need to be regenerated ).

Oracle Cache Policy: LRU (least recently used), which is why oracle and aix work closely together (the same cache policy ).