Log Writer

Log Writer — The Oracle background process responsible for flushing redo entries from the redo log buffer to online redo log files.

Oracle Runtime Context

LGWR flushes redo entries from the redo log buffer to online redo log files. Commit latency is therefore closely tied to the durability path for redo, and storage tail latency or intense redo generation can increase waits associated with synchronous commit.

Process Boundary

LGWR is not the database writer process that writes changed data blocks to datafiles. Redo persistence and data-block writeback serve different recovery roles.

Related Oracle Concepts

• Redo Log Buffer
• Redo Log
• Log Switch
• Durability

Source

• https://docs.oracle.com/en/database/oracle/oracle-database/19/admin/managing-the-redo-log.html