Tuning the Redo Log Buffer

Objectives

		After completing this lesson, you should be able to
		do the following:
		Determine if processes are waiting for space in the redo log buffer
		Size the redo log buffer appropriately
		Reduce redo operations

The Redo Log Buffer

Sizing the Redo Log Buffer

		LOG_BUFFER parameter
		Default value: OS-specific, generally four times the maximum block size

Tuning the Redo Log Buffer

Diagnostic Tools for Tuning the Redo Log Buffer

		V$SESSION_WAIT
		Log Buffer Space event

Guidelines

	The Redo Buffer Allocation Retries value should be near 0; the number should be less than 1% of Redo Entries.

Guidelines

Reducing Redo Operations

	Fewer redo operations require fewer redo entries and thus less redo log buffer space.
	Some ways of reducing the redo entries are:
		Direct Path loading without archiving
		Direct Path loading with archiving using NOLOGGING mode
		Direct Load INSERT in NOLOGGING mode
		Using NOLOGGING mode in SQL statements

Summary

		In this lesson, you should have learned how to:
		Tune log buffer space
		Redo buffer allocation retries
		Size the redo log buffer appropriately
		Reduce redo operations with the NOLOGGING attribute