Friday Oct 02, 2015

Questions you asked: What happens if a column is not In-Memory?

When we're talking to customers or giving presentations questions often get asked that seem simple, but could have an answer that is worth showing with an example rather than just saying, "yes, it works this way". So I'm going to start a series of posts that will address those questions. I will continue the series as I come across what I think are interesting questions.

This first post in the series of "Questions You Asked" will be "What happens if a column is not In-Memory?"

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Saturday Sep 12, 2015

Oracle Open World 2015 Time to plan your schedule!

There are only 6 weeks to go until Oracle Open World, the largest gathering of Oracle customers, partners, developers, and technology enthusiasts, which begins on October 25th in San Francisco.

Of course the In-Memory development group will be there and you will have multiple opportunities to meet up with us, in one of our technical sessions, our hands-on-labs or at the Oracle demogrounds.

This year the In-Memory team has 4 technical sessions and there are also 5 excellent customer sessions you shouldn't miss.

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Monday Sep 07, 2015

Star Schema Challenge - Part 4

In my previous post Star Schema Challenge - Part 3, I reported the first of the in-memory performance results with 25 users querying the star schema in the In-Memory column store (IM column store). In Star Schema Challenge - Part 3.1 I did the same for the de-normalized fact table in the IM column store.  This serves as a comparison between the row format in-memory (buffer cache) and IM column store. For this comparison I stopped at 25 users because it became clear this was enough users for the row store table.  Now it is time to start working towards 100 concurrent users.

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Wednesday Aug 05, 2015

New White Paper on using Database In-Memory with the E-Business Suite Released!

We would like to draw your attention to a new white paper has just been released titled "Using Oracle Database In-Memory with Oracle E-Business Suite".

The white paper details how Database In-Memory works, what the requirements are to use it with the E-Business Suite and works through some use cases and examples.  More details can be found in the My Oracle Support (MOS) Note 2025309.1.

The EBS team worked on hard on this paper and we think it's a great source of information for E-Business customers who want to take advantage of Oracle Database In-Memory. Enjoy the read!

Tuesday Aug 04, 2015

Oracle Database In-Memory on RAC - Part 4

Setting Up Independent In-Memory Column Stores

In previous posts we've talked about how to use RAC services to enable the IM column store to be run on a subset of nodes in a RAC environment. We also mentioned that it is possible, using RAC services and the DUPLICATE sub-clause on engineered systems, to enable rolling patches and upgrades when running the IM column store on a subset of nodes.

In this article we're going to talk about how to set up independent IM column stores on a RAC cluster using services and some database initialization parameters.

But first let's ask and answer the question, why would you want to do this? This might be a good idea if you are trying to enforce application affinity at the node level and don't want to allow inter-instance parallelism.

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Tuesday Jul 21, 2015

Oracle Database In-Memory Bundle Patch 10 Released

The latest Bundle Patch for Database In-Memory has been released. The Bundle Patch is 21188742 or Bundle Patch 10 for Engineered Systems and DB In-Memory (July2015)). This Bundle Patch improves the performance of mixed workload environments (OLTP & DW workloads), as well as enhancing the performance of analytic queries with aggregation. More information on the latest Bundle Patch can be found in the MOS note 21188742.8 or in the Mos note: Bundle Patches for Engineered Systems and DB In-Memory (Doc ID 1937782.1).

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Friday Jul 10, 2015

Star Schema Challenge - Part 2.1

In Star Schema Challenge – Part 2 I revealed baseline results for my query workload running on a 500 million row star schema with all tables marked NO INMEMORY and In-Memory Aggregation prevented using the NO_VECTOR_TRANSFORM hint. With a median of 16.9 seconds per query (allowing for an average think time between queries of 5 seconds), I decided that 25 users were enough for a baseline.

After my first post in this series someone suggested that the best implementation might be a de-normalized table. I decided to satisfy this user’s curiosity and test a de-normalized table also, starting with NO INMEMORY test. (Vector Transform is not applicable to the de-normalized table because it does not join to another table.)

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Friday May 08, 2015

Getting started with Oracle Database In-Memory Part V - Controlling Access

I’m finally going to make good on a promise I made way back in part 3 of our getting started with In-Memory series, to explain how you could control which queries use the In-Memory column store (IM column store) and which don't.

As with all new query performances enhancing features in the Oracle Database, a number of initialization parameters and hints have been introduce that enable you to control when and how the IM column store will be used. This post provides information on the initialization parameter, while the details on the Optimizer hint that control the use of the IM column store can be found on the Optimizer blog.

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Thursday Apr 30, 2015

When to use Oracle Database In-Memory?

At this stage you've probably heard a lot about how Oracle Database In-Memory is an unprecedented breakthrough in Oracle database performance, offering incredible performance gains for a wide range of workloads. What you might not know is when and where it would be best to take advantage of this exciting new technology.

So, we've put together a new whitepaper to share some of the high-level use cases, and explain the scenarios under which Database In-Memory provides a performance benefit. The purpose of this paper is to give you some general guidelines so that you can determine whether your use case is a good match.

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Friday Apr 24, 2015

In-Memory Priority

I'd like to thank everyone who attended our two Hands On Lab sessions at Collaborate last week. We had a great time presenting them and we received some really good feedback. One of the questions that came up, and gets asked periodically, is how does In-Memory priority really work?

Many times people have the misconception that the In-Memory priority attribute affects more than just the order of population but that’s not the case. The only thing the priority affects is the order of population at database startup. We discussed population briefly some time ago, but I think it's worth a quick review.

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Friday Apr 17, 2015

CPU Efficient Query Processing with Database In-Memory

In my last post I talked about In-Memory Aggregation and mentioned that the vector transformation plan is more CPU efficient than alternative plans. In this post I’ll provide a few examples to illustrate just how effective a vector transformation plan can be.

Let’s consider a star schema, with one fact table and 9 dimension tables (time, customer, product, channel and demographic attributes such as age and income).

9 Dimensional Star

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Thursday Apr 09, 2015

Push-Down: Part 2

In our previous post we introduced the concept of push down. The ability to push predicates, aggregations and group-bys down into the scan of a column or columns, allowing Oracle to take full advantage of all the scan performance features of the In-Memory column store. We also illustrated how you could monitor the benefits of push down via session level statistics (v$mystat). What you might not have realized is that we can also see what where clause predicates get push via the execution plan.

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Tuesday Mar 31, 2015

Push-Down: Making Queries Fast!

In our previous posts we discussed the basic architecture of the In-Memory column store (IM column store) and now we want to drill down into some of the unique performance enhancing features. Push-down is one of the optimizations that makes scanning columns in the IM column store very efficient. Oracle Database In-Memory has the ability to push predicates, aggregations and group-bys down into the scan of a column or columns.  This ability to push-down allows us to take advantage of other performance enhancing features of Database In-Memory like SIMD vector processing and storage indexes.

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Monday Feb 16, 2015

Getting started with Oracle Database In-Memory Part V - Aggregation

When most people think about Oracle Database In-Memory (Database In-Memory), the first thing that comes to mind is super fast scanning and filtering operations. But what you may not know is Database In-Memory also includes many SQL optimizations designed to accelerate star and snowflake type queries. We refer to this collection of SQL optimizations as In-Memory Aggregation (IMA). IMA is typically 3-10x faster than ‘conventional’ plans, and that’s in addition to the improvements provided by scanning and filtering the data via the In-Memory column store (IM column store).

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Tuesday Jul 22, 2014

It's here! Oracle Database In-Memory is officially released

Oracle Database was officially release today and is now available for download, which mean Oracle Database In-Memory is officially here!

Along with the software release comes a whole new set of collateral that explains in detail how all of the new Oracle Database In-Memory functionality works. The In-Memory page on has all of the juicy details including the official whitepaper.

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The Oracle Database In-Memory blog is written by the Oracle product management team and sheds light on all things In-Memory.


« October 2015