Oracle cpu_count intel hyperthreading incorrect Oracle Tips by Burleson Consulting Mike Ault - April 14, 2005 On Oracle servers with hyper-threaded processors (i.e. Intel servers on Windows and Linux) Oracle doubles the value for cpu_count. This can be an issue when: • You have turned-on CPU-based optimizer costing - For Oracle and 10g database where the CBO has been set to create execution plans based on CPU costs. Note:153761.1 on MOSC describes the system statistics collection process to turn on CPU costing. Note that according to Bug 2820066 CPU cost is always computed regardless of optimizer mode when optimizer_index_cost_adj is set in Oracle versions less than 10.1.0.2.

However, CPU cost is not used unless the undocumented parameter '_optimizer_cost_model' is set to 'cpu' for example: alter session set '_optimizer_cost_model'=cpu; This parameter defaults to CHOOSE. (from MOSC Note:276877.1) • You are using automatic parallelism (Oracleand earlier) - If cpu_count is doubled and the parallel_automatic_tuning is set to 'true', the CBO will believe that full-table scans are less expensive based on doing them in parallel using a default degree of cpu_count x parallel_threads_per_cpu, and influence the optimizer to choose a full-table scan. As long as there are memory waits for the hyper-threading technology to take advantage of, and the table is spread over multiple disks or is partitioned, this can be a performance boost, however on machines where there are no memory waits, the system is IO constrained or the table is not partitioned then it can reduce performance. • If you are using Oracle parallel query - The number of processors is an important factor in determining the optimal degree of parallelism for a parallel full-table scan as shown in the previous point. How does cpu_count get set? The oracle kernel will determine the number of CPUs on a system during startup. However, some new processors (i.e.

Licensing Cost Metrics. Oracle provides a summary of. With respect to Processor Licensing Factor for. Of the Oracle licensing scheme and a. 1 Oracle Database Appliance Licensing. CPUs and Core Count. Each Oracle Database. Contain 2 CPUs and each CPU has 12 cores. When you deploy Oracle Database.

Intel) have dual cores, where we have two CPU's on one chip, and they appear as two processors when they only occupy one slot, while this is good for software performance it can be hazardous to your license, Oracle has stated that they will charge a CPU license fee for the extra cores in multiple core CPUs. Intel Hyper-threading chips are an example of a single chip that appears to be two CPU's to the Oracle kernel. On Intel-based Oracle servers running Linux or Windows, the cpu_count is set to double the number of physical CPUs when using the hyper-threading setting of the OS or BIOS. Why is cpu_count important? The Oracle cpu_count is determined when you start Oracle.

The cpu_count affects the Oracle cost-based optimizer through many calculated parameters that use cpu_count as their basis and are considered every time that Oracle creates an execution plan for a SQL statement. A doubled setting for cpu_count can result in changes to your explain plans when moving from a single to multiple CPUs or when you increase the number of CPUs in your system. The cpu_count is used to determine the settings for several important init.ora parameters:? Fast_start_parallel_rollback - The default value is 2 times the number of CPU of your system, but some DBAs recommend setting this value to 4 times the c pu_count. • db_block_lru_latches – This defaults to the following formula: (CPU_COUNT x 6) or (DB_BLOCK_BUFFERS/50), whichever is less. In earlier releases it defaulted to CPU_COUNT/2. If you set DB_BLOCK_LRU_LATCHES higher than this max value on systems where it is available (1) and redo allocation latches.

This tip has caused great confusion and debate (again, my apologies), yet this appears to be an issue because the final conclusions are still not completely clear. The questions seem to hinge around: • Does Oracle recommend using hyperthreading on processors with this capability? • Does the doubling of the cpu_count adversely affect parallel query operations?

(Maybe, could be good or bad) • Does the cpu_count affect your Oracle license costs? (Answer: cpu_count no, physical cores, yes. A single-core hyperthreading CPU counts as one CPU for licensing, a dual-core CPU counts as 2) So, let us know, do you use hyper-threading or multiple cores? • If you use hyper-threading, have you had any problems? • If you had to stop using hyper-threading, why?

• If you are using dual-core CPUs, have you had any problems? Here are some comments and notes from MOSC: From Mike Ault: 1. Oracle will set cpu_count at each startup based on the perceived number of CPUs, this should be the same as shown in the top, vmstat and other commands on UNIX and Linux. A hyper-threaded or dual core shows as 2 CPUs for each CPU.

A hyper-threaded CPU is considered a single CPU for licensing, a dual-core CPU is considered 2 CPUs for licensing. Oracle may use multiple lgwr_io_slaves if they are configured by setting dbwr_io_slaves to >0, but their use is not tied to the number of CPUs. Notes from MOSC: Gina Thunder (Oracle employee - MOSC) Oracle will work just fine on any OS that is running and recognizes a hyper-threading enabled system and will take advantage of the logical CPUs to their fullest extent.

Since no additional code was added on the Oracle end to take advantage of hyper-threading, this information is relevant to all Oracle versions and is considered a supported configuration. When Oracle asks the OS how many CPUs are in the system, the OS just reports the total number of logical CPUs.

This is transparent to Oracle as it doesn't know the difference. Unfortunately, I am not sure how this affects licensing. From Note: 205089.1: Oracle and Hyperthreading (Note from Author: When asked pointedly about various comments on use/non-use of hyperthreading, the only answer I got from MOSC analyst was the pointer to this note.) Oracle will work just fine on any O/S that is running and recognizes a hyper-threading enabled system. In addition, it will take advantage of the logical CPUs to their fullest extent (assuming the O/S reports that it recognizes that hyper-threading is enabled). It is also a supported configuration.any issues should be logged as bugs.

All Oracle versions can take advantage of hyper-threading, since no support code has been added for it, all the changes were in the O/S, the bios and the hardware. When Oracle asks the O/S how many CPUs are in the system, the O/S just reports the total number of logical CPUs and Oracle doesn't know the difference. The only bugs reported on Hyper-threading are: Bug: 4202437 The agent, when started, consumes 100% CPU immediately, all targets show as a pending status excepting for database targets which have metric collection errors. When trying to configure a database target with the dbsnmp Customer is using Red Hat Enterprise Linux ES with dual cpu's which had been setup as a multi-processor server with 4 virtual CPUs (hyper threading in place). If the machine is started in multi-processor mode using the smp kernel(2.4.21-27.0.1.ELsmp), the agent goes into a CPU spin as soon as it is started. All the metrics fail with errors.

The same does not occur if the machine is run in single CPU running vanilla kernel. Bug: 1507768 CPUID detection for Intel? 4 processor system: Intel has identified that applications which use the Symantec Just in Time Compiler library file ('symcjit.dll' for Microsoft Windows* operating system and 'symc_jlt.nlm' for Novell Netware* 5.1) may not run properly on Pentium?

4 processor systems because the library does not properly identify the processor. The failure typically is that the affected application simply terminates. Under Microsoft Windows*, the properties of the DLL are: 'Symantec Java! JustInTime Compiler Version 3.10.107 for JDK 1.2 Copyright (C) will also not work. To confirm the version you are using, select the DLL, right click on the selected DLL and select Properties, and then the Version tab. Intel encourages all Software developers to do the following immediately: • Check if your application(s) uses the Symantec Just in Time Library file Request an updated library file from your provider • Test your application with the new library file on Pentium?

4 processor system • Ensure you have plans in place to provide application updates and address customer concerns This will be a huge impact to support. I am not sure how often this CPUID detection is performed with our software but apparently it is done at installation time. 4184876 When setting CPU_COUNT larger than 48 and REDO_BUFFER smaller than 18M (18874368), ORA-7304 is returned and we can't startup database. If setting CPU_COUNT as 47, ORA-7304 is not returned.

I can confirm the reproducibility as below. CPU_COUNT REDO_BUFFER REP? --------- ------------- -------------- 47 1M( 1048576) NO (no error) 47 18M(18874368) NO (no error) 48 1M( 1048576) YES (ORA-7304) 48 16M(16777216) YES (ORA-7304) 48 17M(17825792) YES (ORA-7304) 48 18M(18874368) NO (no error) This problem occurs only on R10g(10.1.0.2 and 10.1.0.3), and doesn't reproduce on R9.2 (9.2.0.6).

On 9.2.0.6, when setting CPU_COUNT=48 and REDO_BUFFER=1M, there is no error and we can startup database. If you like Oracle tuning, see the book ', with 950 pages of tuning tips and scripts. You can buy it direct from the publisher for 30%-off and get instant access to the code depot of Oracle tuning scripts. �� Burleson is the American Team Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.

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We must have been involved in only technical activities and issues on Oracle database every day, but most of the DBA’s must have a limited or no knowledge on how Oracle charges customers with their license models. Most of us might know that Oracle database is free for learning, testing and for any non-profit applications or firms. When I have asked few of my colleagues about the commercial license, they just say that Oracle database licensing is based on a number of cores in your processor. Hope you might be one of them too 🙂. To the professionals who do not know, there are two models from Oracle in purchasing database licenses for commercial purposes. Let us check the licensing terms and their prices for the most widely used features in database enterprise edition.

These license details are gathered from Oracle as on 21-Jan-2016 and might change any time. Type of licenses: Oracle has two types of database licenses and one for software update and meta-link that you can choose from. User based (Named User Plus). Licensed based on a number of users accessing the database whether programmatically or end user. This sort of licensing is very much suitable for a fixed intranet application where users are fixed and no major scalability.

But Oracle sells a minimum of 25 users for Enterprise Edition per CPU. Cons: Even though your application have only 10 users, you will need to pay for 25. Rise Of The Tomb Raider Keygen Free Download. Processor based.

From the name, though we understand it per processor with respect to Oracle this is different to multi-core processors. Today, every server is running on multi-core processors. Oracle calculates the number of processors on the server as “(number of cores) * (multi-core factor)”. Each make of processor has their respective multi-core factor.

Few examples: • 0.5 for Intel/AMD. • 0.25 for UltraSPARC. • 1.00 for IBM Power systems. Cost for Enterprise edition: 1. For User-based: Price per user: 950 $ Software update and support price: 209 $ 2. For Processor based: Processor license: 47,500 $ Software update and support price: 10,450 $ It will be interesting to know how much would few of EE options like RAC, Partitioning etc would cost. Let us see that.

Option Per user license Support license Processor license Support license Diagnostic pack 150 $ 33 $ 7500 $ 1650 $ Tuning pack 100 $ 22 $ 5000 $ 1100 $ 12c Multitenancy 350 $ 77 $ 17500 $ 3850 $ Partitioning 230 $ 50 $ 11500 $ 2530 $ Compression 230 $ 50 $ 11500 $ 2530 $ RAC 460 $ 101 $ 23,000 $ 5060 $ Active dataguard 230 $ 50 $ 11500 $ 2530 $ These prices are additional on top of enterprise license that is purchased. Case study: Hope the numbers that are projected are scattered to get a clear picture of total costs incurred in the database. Let us take a scenario and calculate the licensing costs. Requirement – Calculate license for Oracle database EE with Diagnostic pack, Partitioning and tuning pack including support on Intel quad-core processor for unlimited users. Calculation – • It falls under processor based licensing as the requirement is for unlimited users. • Number of processors (P) = (Quad Core)*(multi-core factor) = 4*0.5 = 2.

• EE Oracle database cost (DB) = 47500 $. • EE options cost (OP) = Diagnostic + Tuning + Partitioning = 7500 $ + 5000 $ + 11500 $ = 24000 $.

• Support license cost (SP) = EE + Diagnostic pack + Tuning + Partitioning = 10450 $ + 1650 $ + 1100 $ + 2530 $ = 15730 $ Total cost is now calculated as = Number of processors*(EE Oracle database cost + EE options cost) + Support license cost = P*(DB+OP) + SP = 2*(0) $ + 15730 $ = 158730 $ It’s 158730 $, that’s very huge isn’t it? You must be now thinking what will be the validity of this license 🙂, right?

That’s another tricky one from Oracle, they have licenses without any term validities and also with 5 or 4 or 3 or 2 or 1 years of term validity. It’s only my perception that the total price we calculated in our case study is valid until you seek for termination. For further details on licensing please refer – Bullet-ins: • Not just production systems, Oracle licenses are applicable to your non-production systems as well. • Oracle may track your “Named User Plus” licenses based on results from the v$license.

• Oracle may track your “Processor” licenses from any of your AWR reports that you upload to meta-link. Was this useful? Like it and share it. Leave your comments! Feel free to give additional information in the comments, that I can validate and include in blog posts or update this as well. Consider i have a web application where i cant predict number of users getting connected.

This web application in the backend connected to oracle server. I have one socket and quad core processor in it. How to calculate licencing cost? Am completly new to oracle.

Does a bussiness less than 1000 users required oracle EE? Cant i have oracle standard edition? Do i need Diagnostic,Tuning,Partitioning options?

Could you please provide me some point of contact in oracle were i get these pricing details based on diffrent senarios? Any ways thanks for your post. Very much informative.