Oracle DB Tuning & Troubleshooting - Interpret an AWR Report

Assess performance-focused design decisions, from data model and physical design to constraints, optimizer-driven execution plans, and parallelism, balancing integrity, redundancy, and materialized view strategies.

Explore how upfront design choices—data types, column order, indexing, and buffer cache—drive database performance, with practical labs on using bind variables and functions to optimize queries.

In session 5, learn how connection management and connection pools impact scalability, comparing single-connection vs repeated connections and outlining best practices for using pools and leaving connections open until shutdown.

Analyze SQL response time by breaking the elapsed time into CPU time and wait time, identify why waits occur, and apply tuning to reduce CPU usage or waiting delays.

Define database time as the sum of CPU and wait time reflecting the database's work. The lecture uses scenarios to show how CPU and wait time determine DB time.

Evaluate when hardware upgrades improve performance versus tuning the root cause. Measure user, application, and database response times to set non-functional requirements guiding efficient tuning.

Understand db time as the sum of active time in the database, excluding idle time, and use wait events to spot bottlenecks such as buffer busy waits and latch contention.

Explore wait events caused by shared pool and dictionary cache contention, and learn to reduce IO by using indexing, partitioning, and table reorganization to keep data in memory.

Explain how sequential read and scattered read i/o waits occur in Oracle queries, contrasting index lookups with full table scans, and show how block reads and buffer cache affect performance.

Understand space management in Oracle databases: dictionary-managed vs locally managed table spaces, manual vs automatic segment management, high watermark, free lists, and how block migration and rotation optimize performance.

Determine the optimal Oracle block size by workload, choosing between transaction processing and querying. Benchmark five sizes: two, four, eight, sixteen, and thirty-two kilobytes, to maximize concurrency and minimize waits.

Explore how to read awr metrics and memory statistics to diagnose wait events, analyze physical reads vs buffer gets, and understand block size and execution plan choices.

Explore block size strategies and space management in Oracle, comparing manual and automatic segment space management and settings like BCB free, BC2, BC3, free lists, and high watermarks.

Explore alternate storage techniques for Oracle databases, including heap and partitioned tables, cluster tables, and materialized views. Understand how local and global indexes, partition pruning, and sharding affect performance.

Explore how storage performance affects Oracle database tuning, using IOPS, MBBS, and RPM; learn about volume managers, tiered storage, compression, heat maps, and AWR-based troubleshooting.

Identify root causes of database slowdowns using diagnostic data from AWR snapshots, dynamic performance views, and the automatic workload repository to obtain a holistic view of activity over time.

Learn how to interpret an AWR report by selecting two close snapshots to reveal the database's performance in a chosen time window, identify waits, top queries, and issues.

Interpret AWR reports by comparing hourly snapshots to reveal top SQL executions and their wait times, and assess database health through sessions, logins, and CPU versus wait metrics.

Learn to interpret an AWR report, create baselines from snapshots, and analyze top waits, CPU, IO, and SQL queries to drive performance tuning.

Learn to interpret an AWR report to identify the queries and objects driving IO and CPU waits, analyze elapsed time and top offenders, and pinpoint root causes for tuning.

Learn to read an AWR report by focusing on the relevant sections, using snapshots and elapsed time to pinpoint bottlenecks, CPU, waits, and service statistics.

Learn how to create an AWR report between beginning and end snapshots and why an instance restart between them prevents aggregation.

Tune the buffer cache by sizing memory, using multiple buffer pools (keep, recycle, default), and leveraging flash cache to improve hit ratio and reduce disk i/o.

Explore the Oracle shared pool, its library cache and dictionary caches, and how locks, serialization, and result cache influence performance, invalidations, and reloads in query execution.

Master PGA tuning and memory advisories in Oracle AWR to optimize buffer cache, temporary tablespace, and joins, with actionable guidance from advisory reports.

Identify i/o hotspots from the AWR report by analyzing read/write rates, latency, and file types, then optimize with indexing, partitioning, views, and memory caching to reduce disk bottlenecks.

Compare ASH and AWR to diagnose bad SQL by examining active session history, which samples activity every second for the last 60 minutes, complementing AWR snapshots that show top SQL.

Uncover how SQL profiles affect the Oracle optimizer decisions by comparing explained plans with actual execution statistics, and learn when to refresh profiles after changing object statistics.

Learn how huge pages enlarge memory pages to exceed the default partition limit, enabling Oracle to manage larger memory and improve utilization.