Oracle Memory Management Interview Preparation Guide

Oracle Memory Management Interview Questions and Answers will guide us that Oracle Memory management is the act of managing computer memory. This involves providing ways to allocate partions of memory to programs at their request, and freeing it for reuse when no longer needed. The management of main memory is critical to the computer system. So learn the basics and advance level Oracle Memory Management with the help of this Oracle Memory Management Interview Questions with Answers guide

61 Memory Management Questions and Answers:

1 :: What is the significance of having storage clause?

We can plan the storage for a table as how much initial extents are required, how much can be extended next, how much % should leave free for managing row updations etc.

2 :: What is the functionality of SYSTEM table space?

To manage the database level transactions such as modifications of the data dictionary table that record information about the free space usage.

3 :: How does Space allocation table place within a block?

Each block contains entries as follows
Fixed block header
Variable block header
Row Header,row date (multiple rows may exists)
PCTEREE (% of free space for row updation in future).

4 :: What is the role of PCTFREE parameter is storage clause?

This is used to reserve certain amount of space in a block for expansion of rows.

5 :: What is the OPTIMAL parameter?

To avoid the space wastage we use OPTIMAL parameter.

6 :: What is a shared pool?

The Shared Pool environment contains both fixed and variable structures. The Fixed structures remain relatively the same size, whereas the variable structures grow and shrink based on user and program requirements.

Used To Store
Most Recently Executed SQL Statements
Most Recently used Data definitions
It Consists of two Key performance - related memory structures
Library Cache & Data Dictionary Cache

Shared Pool is sized by SHARED_POOL_SIZE

7 :: What is mean by Program Global Area (PGA)?

It is area in memory that is used by a Single Oracle User Process.

8 :: What is a data segment?

Data segment are the physical areas within a database block in which the data associated with tables and clusters are stored.

9 :: What are the factors causing the reparsing of SQL statements in SGA?

Due to insufficient Shared SQL pool size.

Monitor the ratio of the reloads takes place while executing SQL statements. If the ratio is greater than 1 then increase the SHARED_POOL_SIZE.

LOGICAL & PHYSICAL ARCHITECTURE OF DATABASE.

10 :: What is Database Buffers?

Database buffers are cache in the SGA used to hold the data blocks that are read from the data segments in the database such as tables, indexes and clusters DB_BLOCK_BUFFERS parameter in INIT.ORA decides the size.