Performance tuning

Richard Foote's picture

Question: Anything Wrong With Query Performance? (Straight To You)

I have a query that runs pretty darn efficiently, here’s the setup: So the query basically returns 1000 rows based on the CODE column and it does so using an index on CODE. The CBO has got the costings for this just about spot on. For 1000 rows returned, it does so with just 1006 […]

Uwe Hesse's picture

Why INSERT causes TX – row lock contention or TM – contention in #Oracle 600w,

Uwe Hesse's picture

Combining Resource Consumer Groups with Application Modules in #Oracle 600w,

rshamsud's picture

IOUG Collaborate 2017

I have a few presentations scheduled in IOUG Collaborate 2017, Las Vegas.

1. Session: 621: RAC Clusterware internals
**Date/time: Mon, Apr 03, 2017 (01:30 PM – 02:30 PM) : Jasmine A

2. Session: RAC cache fusion internals. ( OakTable track )
**Date/time: Wed, Apr 05, 2017 (09:45 AM – 10:45 AM) Room: South Seas C

3. Session: 479: An in-depth review of ASM and internals
**Date/time: Wed, Apr 05, 2017 (02:45 PM – 03:45 PM) : Palm B

Presentation files ( Updated after the presentations).

Thank you for coming to my presentation(s).

rshamsud's picture

RMOUG Training days 2017

I will be speaking about the following topics in Rocky Mountain Oracle User group Training days (RMOUG, Denver) February 7-9, 2017.

Come to my presentations and say Hi to me </p />
    <div class=»

Uwe Hesse's picture

Real-Time Materialized Views in #Oracle 12c

helps 600w, https://uh

Uwe Hesse's picture

How to reduce Buffer Busy Waits with Hash Partitioned Tables in #Oracle

fight_contention_2 576w, 144w" sizes="(max-width: 288px) 100vw, 288px" />

Large OLTP sites may suffer from Buffer Busy Waits. Hash Partitioning is one way to reduce it on both, Indexes and Tables. My last post demonstrated that for Indexes, now let’s see how it looks like with Tables. Initially there is a normal table that is not yet hash partitioned. If many sessions do insert now simultaneously, the problem shows:

Uwe Hesse's picture

How to reduce Buffer Busy Waits with Hash Partitioned Indexes in #Oracle

fight_contention 150w, 474w" sizes="(max-width: 300px) 100vw, 300px" />

Buffer Busy Waits can be a serious problem for large OLTP systems on both tables and indexes. If e.g. many inserts from multiple sessions occur simultaneously, they may have to compete about the same index leaf blocks like the picture below shows:

Uwe Hesse's picture

How to speed up Data Pump Import by suppressing redo generation in #Oracle 12c

With your database in archive log mode, a Data Pump Import may be severely slowed down by the writing of much redo into online logs and the the generation of many archive logs. A 12c New Feature enables you to avoid that slow down by suppressing redo generation for the import only. You can keep the database in archive log mode the whole time. Let’s see that in action!

First without the new feature:

pete.sharman's picture

Read Only Users and Database Performance

One of the questions we see being asked reasonably frequently is how to allow read only access to someone who wants to view database performance issues, using tools such as Real Time ADDM, ASH Analytics and so on. This is generally asked for someone like an application developer, who can use this information to identify performance issues in Production and then fix the root cause in their Development environments.

Well, that’s a reasonable question to ask, and indeed if you search the internet you can find different ways of doing something like this. For EM12c, one of the best write-ups I’ve seen done on this was of course by one of my colleagues, Courtney Llamas. That write-up is available here.

To prevent automated spam submissions leave this field empty.
Syndicate content