1. What is IMU? What is the main role of IMU, that is, to solve the problem?
IMU--->in Memory undo,10g new features, the database will open up separate memory areas in shared pool to store the Undo information.
Each new transaction is assigned a IMU buffer (private), a buffer with many node, one node equivalent to a
IMU technology and redoprivatestrand Technology in Oracle
Oracle030
IMU technology and redo private strand Technology in oracle030Oracle
3. Explain the Oracle IMU Mechanism
Select * from v $ sysstat where name like "% IMU % ';
STATISTIC #, NAME, CLASS, VALUE, STAT_ID312
possibly generate a large number of read I/O operations, which are resource-intensive operations. If you can reduce the Redo and Undo writes of Undo in these processes, it can obviously greatly improve database performance and reduce resource consumption and usage.
Oracle introduced the In Memory Undo (IMU) technology In the database starting from Oracle10g. With this technology, the database will be In the Shared Memory (Shared Pool) the independen
IMU technology and redo private strand Technology in Oracle, imustrand
Oracle030
IMU technology and redo private strand Technology in oracle030Oracle
3. Explain the Oracle IMU Mechanism
Select * from v $ sysstat where name like '% IMU % ';
STATISTIC #, NAME, CLASS, VALUE, STAT_ID312
First look at a phenomenon:
19:33:31 HR @ orcl (^ ω ^) Select name, value19: 33: 59 2 from V $ mystat A, V $ statname B19: 33: 59 3 where. statistic # = B. statistic #19:33:59 4 and B. name = 'redo size' 19: 33: 59 5/name value ---------- redo size 108419: 34: 01 HR @ orcl (^ ω ^) insert into T1 values (112, 'aoqinqin'); 1 line has been created. 19:36:54 HR @ orcl (^ ω ^) Select name, value19: 37: 08 2 from V $ mystat A, V $ statname B19: 37: 08 3 where. statistic # = B. statistic #19:37:08 4
Tags: Format verify loopback 4.0 SID fail for 11g 11.2.0.4[20180823] IMU and DB Link.txt--//when using DB link to view remote tables, a small log is actually generated.--//when combined with the IMU, it can cause the IMU to fail.1. Environment:[Email protected]> @ ver1Port_string VERSION BANNER------------------------------ -------------- ------------------------
Experiment content: The Redo Log Content format of the DML statement produced in the non-IMU mode is interpreted, the database version: 11.2.0.4
The most detailed explanation is update.
Experimental environment Preparation
The IMU feature is turned on by default in 11G, and this feature needs to be turned off for this experiment.
Alter system set "_in_memory_undo" =FALSE;
Alter system set "_in_memory_u
! [GY-85] (http://images.cnblogs.com/cnblogs_com/hangxin1940/466697/o_gy85.jpg "GY-85 ")
9-axis IMU sensor (GY-85 module) can also be seen as three modules 'itg3205 Three-Axis Gyroscope sensor ''' adxl345 three-axis accelerator tilt sensor ''' hmc5883l Electronic Compass'
The GY-85 Module Interface is I2C and can be easily linked to the Arduino/Raspberry Pi.
# PreparationsMake sure the system has installed the quick2wire library, if not, move here to
In the work contact with the gyroscope, and this Chinese expression in English there are many distinctions, such as MEMS, Gyro, IMU and so on.
Reference article:"1" Baidu know: Gyro, compass, IMU, MEMS four differencesPrinciple of "2" Csdn:imu
From the beginning, the Gyro has two properties: the axis and the precession, thus invented the gyroscope.The gyroscope itself measures the single-axis angular devi
Cartographer_rosEntry file: node_main.ccThe entry function is main, as shown below:Initialize node: cartographer_node;The Run function loads the configuration file loadoptions () and processes the subscribed topic according to the configuration file. such as Imu
note whether the cartographer accepts IMU data, depending on the conditions of the If judgment, which are configured in "Backpack_2d.lua". It
Tags: Test port linux C TPS Tutorial define device average TomReference: Https://github.com/Razor-AHRS/razor-9dof-ahrs/wiki/Tutorial#sensor-calibrationThe hardware used in the link is SparkFun "9DOF Razor IMU", This article uses the GY-951, the same applies.Hardware Connection method:GY-951 module + Mini FT232RL (USB to serial port module)Setup software:Download
This topic is discussed in ITPUB. Link: www.itpub.netthread-1838538-1-1.html 1. What is IMU? What is the main role of IMU, that is, to solve what problems? IMU --- InMemoryUndo, new 10g feature, the database will open up an independent memory area in the sharedpool to store Undo information, each new transaction will
This topic is discussed in ITPUB. Link: http:/
of the four-rotor aircraft, and the position control is based on the perfect attitude control. As already mentioned, it is unreliable to obtain the angle value only by gyroscope integral, because of the inherent drift of the gyroscope, the error caused by the integral becomes more and more large, and the accelerometer is susceptible to noise and vibration disturbance. Therefore, the two kinds of data are fused using various algorithms to obtain the ideal attitude data. The more common fusion al
a large amount of I/O. Undo is also expensive.
New 10g feature: IMU Mechanism
IMU allocates an IMU pool in the shared pool to cache rollback blocks. Each new transaction is allocated an IMU buffer (private). A buffer contains many nodes, and a node is equivalent to a block (rollback block ). There are roughly two adva
files if it is not in the data buffer. Second, all undo changes must also record the redo, it is written into the redo log when the transaction is committed. Oracle introduces the new in-memory undo feature, which stores the Undo information in the memory structure to ease the overhead of traditional undo management.IMU allocates a piece of memory space (IMU pool) in the Shared Pool. Each new transaction will allocate an
This post is translated from the IMU (accelerometer and Gyroscope devices) guide used in embedded applications.This article mainly introduces the mathematical models and basic algorithms of accelerometers and gyroscopes, and how to fuse the two, focusing on the discussion of algorithms and ideas.IntroducedThe purpose of this guide is to introduce inertial MEMS sensors, especially accelerometers and gyroscopes, and other integrated
Source Address: http://www.geek-workshop.com/thread-1695-1-1.htmlThis post is translated from the IMU (accelerometer and Gyroscope devices) guide used in embedded applications.This article mainly introduces the mathematical models and basic algorithms of accelerometers and gyroscopes, and how to fuse the two, focusing on the discussion of algorithms and ideas.IntroductionThe purpose of this guide is to introduce inertial MEMS sensors, especially accel
. The header of the data block to be modifiedthings TroughPosition, find a thing slot and write the information about things.3.IMU mechanismThe traditional undo,oracle treats the undo table space as equal to the normal table space. Now, with the IMU technology, after the start of the thing, the need to rollback the block is no longer required to be transferred from the disk, directly in the shared pool in t
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.