Guidelines

Why is my Oracle Database slow?

by Rhyley Bryan

Why is my Oracle Database slow?

The most common causes of slow performance are as follows: Excessive round-trips from the application server to the database. Ideally, each UI operation should require exactly one round-trip to the database. Sometimes, the framework will require additional round-trips to retrieve and make session data persistent.

Why is my database slow?

Missing indexes, an inadequate storage I/O subsystem, or a slow network are only some of the possible reasons why a SQL Server database engine might slow down, which is why finding the true cause of a performance bottleneck is vital. Missing indexes. Poor index design. Poorly designed database schema.

How do I make my Oracle query run faster?

Partitioning your data and creating local partitioned indexes can improve your query performance. On a partitioned table, each partition has its own set of index tables. Effectively, there are multiple indexes, but the results from each are combined as necessary to produce the final result set.

How would you troubleshoot a slow running query in Oracle?

Step by Step: How to troubleshoot a slow running query in Oracle

  1. Step 1 – Find the SQL_ID of the slow running query.
  2. Step 2 – Run the SQL Tuning advisor for that SQL_ID.
  3. Step 3 – Check the sql plan hash value and pin the good plan:

How do I know if Oracle is running slow?

Do You Know If Your Database Is Slow?

  1. SQL> select to_char(begin_time,’hh24:mi’) time, round( value * 10, 2) “Response Time (ms)”
  2. from v$sysmetric.
  3. where metric_name=’SQL Service Response Time’
  4. TIME Response Time (ms)
  5. ————— ——————
  6. 07:20 .32.

How do I troubleshoot Oracle performance issues?

There are six best practices DBAs should follow when conducting Oracle database performance tuning:

  1. Improving SQL execution efficiency.
  2. Increasing availability.
  3. Managing operating system resources.
  4. Optimizing storage performance.
  5. Using the query optimizer.
  6. Using and configuring memory.

How do I know if my database is slow?

If the whole database is not slow, your checklist is complete. Check if all the nodes are UP….Alternatives are:

  1. Adjust general pool to use less than 95%.
  2. Create an additional Pool of size of the difference needed to accommodate catalog.
  3. Adjust the METADATA resource pool to free memory for the catalog.

How do I make my database slow?

Top 5 Ways To Improve Your Database Performance

  1. Optimize Queries. In most cases, performance issues are caused by poor SQL queries performance.
  2. Create optimal indexes.
  3. Get a stronger CPU.
  4. Allocate more memory.
  5. Data defragmentation.
  6. Disk Types.
  7. Database version.

What is Oracle hint?

Hints let you make decisions usually made by the optimizer. As an application designer, you might know information about your data that the optimizer does not know. Hints provide a mechanism to direct the optimizer to choose a certain query execution plan based on the specific criteria.

How do you optimize a query?

It’s vital you optimize your queries for minimum impact on database performance.

  1. Define business requirements first.
  2. SELECT fields instead of using SELECT *
  3. Avoid SELECT DISTINCT.
  4. Create joins with INNER JOIN (not WHERE)
  5. Use WHERE instead of HAVING to define filters.
  6. Use wildcards at the end of a phrase only.

How do you troubleshoot a slow query?

Troubleshoot Slow-Running Queries In SQL Server

  1. Using SQL Server Profiler. SQL Server Profiler is a separate application that lets you view the queries being run on the SQL Server database engine in real time as they complete.
  2. Using Extended Events.
  3. Find the Problem.
  4. Over Executing NonClustered Indexes.
  5. Scans into Seeks.

How do you troubleshoot a slow running query?

In this article

  1. Introduction.
  2. Verify the Existence of the Correct Indexes.
  3. Remove All Query, Table, and Join Hints.
  4. Examine the Execution Plan.
  5. Examine the Showplan Output.

What should I do if my Oracle database is slow?

The most thorough way to approach an Oracle performance problem is to do an extended SQL trace of one or more of the slow sessions, profile them, and see where they’re actually spending their time.

What’s the best way to solve an oracle performance problem?

The most thorough way to approach an Oracle performance problem is to do an extended SQL trace of one or more of the slow sessions, profile them, and see where they’re actually spending their time. An excellent source of info on doing this is Cary Millsap’s book which you can see the first chapter of here.

Are there any useful tools for Oracle Database?

If yes, you have access to couple of useful tools: ADDM (Automatic Diagnostic Monitor) and AWR (Automatic Workload repository). The AWR reports may be difficult to understand at first, but they can give invaluable information on what is really happening in the database.

What does DB control do in Oracle 11g?

You’re on the 11g, this means you can start the “DB Control”, it is a limited version of Enterprise Manager (Or maybe you have fully licensed Enterprise manager). The DB Control provides web interface, it lets you see performance-related information among other things, it collects a lot of useful information.