Identifying Oracle Database Hot Blocks using Oracle Table v$system_event: A Comprehensive Guide

Purpose

Understanding Hot Blocks

In an Oracle database, a "hot block" refers to a data block in the buffer cache that experiences a disproportionately high volume of concurrent requests. This contention can lead …

Oracle "Data Block" Waits using Oracle table v$waitstat to identify disk Contention

Purpose

In Oracle databases, waiting for "data blocks" signifies contention for specific data blocks in memory. This contention can lead to performance bottlenecks and slowdowns. Understanding the root cause of …

Unmasking Buffer Busy Waits in Oracle: A Deep Dive with v$session_wait

Purpose

"Buffer busy waits" are a common performance bottleneck in Oracle databases, occurring when multiple sessions try to access the same data block concurrently. Identifying the specific blocks and understanding the reasons behind …

Oracle Database: Understanding Lock Conflicts with dba_lock and Column Formatting

Purpose

This Oracle SQL query is designed to investigate and understand lock conflicts within your database, particularly those causing performance bottlenecks. It leverages the dba_lock view to expose critical lock information in a …

Oracle Database: Uncover Blocking Sessions with a Powerful SQL Query using v$lock

Purpose

Identify and resolve performance bottlenecks in your Oracle database by detecting blocking sessions using this powerful SQL query. Gain insights into the query's mechanics and learn how to optimize your database for smoother …

Oracle Database: Identifying Parent Tables for Repair or Re-import using dba_constraints

Purpose

When working with Oracle databases, ensuring data integrity is paramount. Foreign key constraints play a crucial role in maintaining relationships between tables, but disabled constraints can signal potential issues that …

Oracle SQL: Finding Missing Foreign Key Values (ORA-02298)

Purpose

This Oracle SQL query is designed to help identify missing foreign key values within your database. This is particularly useful when troubleshooting the ORA-02298: cannot validate (constraint_name) - parent keys not found error, which indicates a …

Enabling Disabled Foreign Key Constraints in Oracle Database using dba_constraints

Purpose

This SQL query generates a list of SQL statements that can be executed to enable all disabled foreign key constraints in an Oracle database.

Sample SQL Command

1set lines 100 pages 999
2select	'alter table '||owner|| …

Oracle Undo: A Deep Dive into DBA_UNDO_EXTENTS

Unlock the secrets of Oracle's undo mechanism with this in-depth guide to the DBA_UNDO_EXTENTS view. Learn how to analyze undo tablespace usage, interpret extent statuses (ACTIVE, UNEXPIRED, EXPIRED), and gain valuable insights for proactive database management. Avoid …

Real-Time Oracle Rollback Detection: Is Your Database Undoing Changes?

This SQL query monitors real-time rollbacks in Oracle databases. It identifies which sessions are actively undoing changes and tracks their progress by observing the used_ublk value (the number of undo blocks in use). When used_ublk reaches zero, …