[ODI] chapter1 When Update statement is executed, How does oracle undo work?EXEM
When an update statement is executed in Oracle, the undo mechanism works as follows:
1. Oracle generates a new change undo (CU) block in the buffer cache to track the before image of the updated row.
2. The original data block is copied to the new CU block, and the original block is marked as a change redo (CR) block.
3. Oracle allocates memory and assigns a transaction ID (XID) to the transaction in the V$TRANSACTION view, tracking the undo information for the update.
This document discusses transaction slot before-image chaining in Oracle databases. It begins with questions about cleanout, undo storage, and commit SCNs. It then describes the architecture of before-image chaining, where commit SCNs and other metadata are stored in undo blocks and transaction control blocks to link a transaction's multiple before-images together. Diagrams show how before-images are chained across multiple undo blocks using these references.
[ODI] chapter2 what is "undo record chaining"?EXEM
- Undo record chaining allows Oracle to rollback multiple transactions by linking undo records together in a chain.
- When an update is made, an undo record is generated and added to the undo block. A new record contains the before image of the update.
- Undo records for a transaction are chained together by transaction ID and sequence number. This allows Oracle to efficiently rollback a whole transaction by traversing the undo record chain.
The document describes the Oracle undo segment and how it tracks changes to data in transactions.
1) It shows the initial state when a value of "A" is entered into a table column.
2) It then shows an update transaction that changes the value from "A" to "B", with the undo segment recording the before image of "A".
3) A second update transaction is shown, changing the value from "B" to "C", with the undo segment recording the before images of "B" and "A".
[ODI] chapter3 What is Max CR DBA(Max length)? EXEM
The document discusses how Oracle's buffer cache allocates consistent read (CR) blocks and current (CU) blocks when updating a single column value in a table multiple times with commits. It finds that with the parameter _db_block_max_cr_dba set to 6, Oracle allocates a new CU block for each update while reusing the first 6 CR blocks, allocating a new one for the 7th update. Screenshots from an internal tool show the state of blocks in the buffer cache after each update.
1. The document describes how Oracle allocates CU blocks and CR blocks in the buffer cache when updating column values from A to I through consecutive commits.
2. It shows the expected outcome of 6 CR blocks being allocated for the 6 updates before a new CU block is needed.
3. An analysis using ODI Analyzer on an Oracle database shows this expected behavior occurring, with CR blocks 1-6 being allocated and reused for each update before a new CU block is created on the 7th update.
This document summarizes several myths about database redo, undo, commit, and rollback operations. It presents test cases and analysis to debunk the myths. The author is an experienced Oracle DBA who specializes in performance tuning and internals. Sample redo records are displayed and analyzed to explain how operations like rollback do generate redo. The document aims to clarify misunderstandings about the internal workings of Oracle's transaction and redo logging.
[ODI] chapter1 When Update statement is executed, How does oracle undo work?EXEM
When an update statement is executed in Oracle, the undo mechanism works as follows:
1. Oracle generates a new change undo (CU) block in the buffer cache to track the before image of the updated row.
2. The original data block is copied to the new CU block, and the original block is marked as a change redo (CR) block.
3. Oracle allocates memory and assigns a transaction ID (XID) to the transaction in the V$TRANSACTION view, tracking the undo information for the update.
This document discusses transaction slot before-image chaining in Oracle databases. It begins with questions about cleanout, undo storage, and commit SCNs. It then describes the architecture of before-image chaining, where commit SCNs and other metadata are stored in undo blocks and transaction control blocks to link a transaction's multiple before-images together. Diagrams show how before-images are chained across multiple undo blocks using these references.
[ODI] chapter2 what is "undo record chaining"?EXEM
- Undo record chaining allows Oracle to rollback multiple transactions by linking undo records together in a chain.
- When an update is made, an undo record is generated and added to the undo block. A new record contains the before image of the update.
- Undo records for a transaction are chained together by transaction ID and sequence number. This allows Oracle to efficiently rollback a whole transaction by traversing the undo record chain.
The document describes the Oracle undo segment and how it tracks changes to data in transactions.
1) It shows the initial state when a value of "A" is entered into a table column.
2) It then shows an update transaction that changes the value from "A" to "B", with the undo segment recording the before image of "A".
3) A second update transaction is shown, changing the value from "B" to "C", with the undo segment recording the before images of "B" and "A".
[ODI] chapter3 What is Max CR DBA(Max length)? EXEM
The document discusses how Oracle's buffer cache allocates consistent read (CR) blocks and current (CU) blocks when updating a single column value in a table multiple times with commits. It finds that with the parameter _db_block_max_cr_dba set to 6, Oracle allocates a new CU block for each update while reusing the first 6 CR blocks, allocating a new one for the 7th update. Screenshots from an internal tool show the state of blocks in the buffer cache after each update.
1. The document describes how Oracle allocates CU blocks and CR blocks in the buffer cache when updating column values from A to I through consecutive commits.
2. It shows the expected outcome of 6 CR blocks being allocated for the 6 updates before a new CU block is needed.
3. An analysis using ODI Analyzer on an Oracle database shows this expected behavior occurring, with CR blocks 1-6 being allocated and reused for each update before a new CU block is created on the 7th update.
This document summarizes several myths about database redo, undo, commit, and rollback operations. It presents test cases and analysis to debunk the myths. The author is an experienced Oracle DBA who specializes in performance tuning and internals. Sample redo records are displayed and analyzed to explain how operations like rollback do generate redo. The document aims to clarify misunderstandings about the internal workings of Oracle's transaction and redo logging.
Compiling Imperative and Object-Oriented Languages - Garbage CollectionGuido Wachsmuth
The document discusses garbage collection techniques. It describes mark and sweep garbage collection, which involves two steps: 1) marking all reachable records from program roots like variables; and 2) sweeping through and deleting any unmarked records. Reference counting is also covered, where records with a reference count of 0 are deleted. Copy collection and generational garbage collection are briefly mentioned.
Dbms plan - A swiss army knife for performance engineersRiyaj Shamsudeen
This document discusses dbms_xplan, a tool for performance engineers to analyze execution plans. It provides options for displaying plans from the plan table, shared SQL area in memory, and AWR history. Dbms_xplan provides more detailed information than traditional tools like tkprof, including predicates, notes, bind values, and plan history. It requires privileges to access dictionary views for displaying plans from memory and AWR. The document also demonstrates usage examples and output formats for dbms_xplan.analyze.
1. The COBOLBinaryHelper loads COBOL data from SequenceFiles and parses the bytes into a structured record based on the provided COPYBOOK.
2. The record contains the raw COBOL field values as bytearrays as well as parsed versions as strings and arrays.
3. Pig UDFs can then operate directly on the parsed fields to analyze and transform the COBOL data.
The document describes the steps to build a mechanically scanned LED clock called "The Propeller Clock". It uses a DC motor to spin a circuit board with LED digits. The motor's armature is used to power the circuit board. A PIC microcontroller is programmed to control the LED display and keep time. Modifications are suggested to adapt it to different motors.
The Ring programming language version 1.9 book - Part 68 of 210Mahmoud Samir Fayed
This code defines a GraphicsApp class that uses RingOpenGL and RingAllegro to render multiple textured cubes. The class loads bitmap textures, sets up the OpenGL viewport and projection matrix, and draws cubes with different textures applied. It rotates the cubes over time and handles user input and redraw events to animate the scene.
The document contains SQL commands that create tables, insert data, and perform queries on the tables. The tables created are studies, software, and programmer. Data is inserted and various queries are run to retrieve, aggregate, and analyze the data. Key information summarized includes:
- Tables were created to store student studies data, software project data, and programmer details.
- Data was inserted into the tables and various queries were run to retrieve, calculate statistics on, and analyze the data across the tables.
- Queries included finding averages, minimums, maximums, counts, sums, and using functions like trunc, round, and to_char to manipulate dates and strings.
This document provides an overview of memory management in the kernel, including:
1. The bootmem allocator is used initially by the kernel to manage memory, using a bitmap to track free/reserved pages.
2. Later, the buddy system is used to manage memory, tracking more complex page statuses using struct page.
3. Memory is divided into zones like Normal and Highmem, with boundaries defined differently on x86 and ARM architectures.
MySQLinsanity! This document provides an overview of Stanley Huang's MySQL performance tuning experience and expertise. It begins with introductions and background on Stanley Huang. It then discusses the typical phases of MySQL performance tuning projects, including SQL tuning and RDBMS tuning. Specific tips are provided around topics like slow query logging, index usage, partitioning, and server configuration. The document concludes with an invitation for questions.
This document contains assembly code for initializing an LCD display and related hardware on a microcontroller. It defines constants for LCD cursor positioning and characters for displaying volume levels and note lengths. It includes functions for resetting the LCD cursor, moving the cursor left and right, and setting the cursor position. It handles a complication where position 64 wraps to 84, to ensure proper cursor positioning.
This document provides an introduction to cost based optimization. It discusses key concepts like selectivity, cardinality, histograms, and correlation issues. The author is Riyaj Shamsudeen, an Oracle expert with 18 years of experience. Sample code and examples are provided to illustrate how to calculate selectivity and cardinality accurately to improve query optimization. Extended statistics are highlighted as a way to address correlation between column predicates in Oracle 11g and above.
The Ring programming language version 1.5.3 book - Part 68 of 184Mahmoud Samir Fayed
This document describes code for rendering multiple textured cubes in 3D using RingOpenGL and RingAllegro. It defines a GraphicsApp class that initializes OpenGL and Allegro, loads three bitmap textures, and contains functions to draw the scene with multiple cubes, apply rotations, and handle events. The cubes are drawn by binding each texture and rendering the six faces of each cube with texture coordinates. Rotations are applied around the X, Y and Z axes each frame to animate the scene.
The document discusses IO subsystem architecture in Linux. It contains 3 layers: block layer, DM layer and request queue/elevator. The block layer handles generic block IO requests and completion events. The DM layer consists of components like LVM2 and EVMS. The request queue schedules requests using algorithms like deadline and anticipatory. It also contains probes and tracepoints to monitor IO events.
This document provides information on advanced root cause analysis techniques for VMware ESX environments. It discusses log file locations and purposes, how to increase logging levels for specific drivers to provide more debug information, listing and setting loadable module parameters, setting up serial logging and remote syslog, and forcing crashes to collect memory dumps. The document aims to equip support engineers with tools and techniques for thorough troubleshooting when initial logs are insufficient.
VMware’s Nathan Small who works as a Staff Engineer at Global Support Services has put together a great presentation about Advanced Root Cause Analysis. The presentation was designed to give you more insight into how a VMware Technical Support Engineer reviews logs, gathers data and performs in-depth analysis. Nathan is hoping to show you the skills they’re using every day to help determine the root cause for an issue in your environment. With this core knowledge, you will become more self-sufficient within your own environment and be able to diagnose an issue as it occurs rather than after the damage has been done.
OSDC 2017 - Werner Fischer - Linux performance profiling and monitoringNETWAYS
Nowadays system administrators have great choices when it comes down to Linux performance profiling and monitoring. The challenge is to pick the appropriate tools and interpret their results correctly.
This talk is a chance to take a tour through various performance profiling and benchmarking tools, focusing on their benefit for every sysadmin.
More than 25 different tools are presented. Ranging from well known tools like strace, iostat, tcpdump or vmstat to new features like Linux tracepoints or perf_events. You will also learn which tools can be monitored by Icinga and which monitoring plugins are already available for that.
At the end the goal is to gather reference points to look at, whenever you are faced with performance problems.
Take the chance to close your knowledge gaps and learn how to get the most out of your system.
This presentation discusses new features and changes introduced in Oracle Database 11g. It provides snippets of SQL code demonstrating features such as error logging, transaction safety settings, hashing functions, and list aggregation. It also covers real-time SQL monitoring and optimization.
Secrets of building a debuggable runtime: Learn how language implementors sol...Dev_Events
Bjørn Vårdal, J9VM Software Developer, IBM, @bvaardal
New language runtimes appear all the time, but most of them die young. Failure can be attributed to
different reasons, but an important factor is that lack of support can limit the community’s and
industry’s willingness to adopt the new language.
Quicker development and improved serviceability allows emerging languages to overcome this obstacle.
By building on the proven technology available in Eclipse OMR, language developers can get more than
performance and stability; you also get tools that help you quickly debug your language runtime,
allowing you to provide competitive serviceability.
From this presentation, you will learn how to enable Eclipse OMR’s mature debugging features in your
language runtime, and also how Eclipse OMR can assist with development and debugging
1. The document describes various Moshell commands used for managing RBS nodes.
2. The acc 0 manualrestart command is used to restart the RBS node, while the pol 5 5 command polls the node every 5 seconds to check when the MO service is ready after restart.
3. Other commands described are for checking CV configuration (cvcu, cvls), managing CVs (cvset, cvmk, cvrm), and accessing measurement data (st mme, ue print).
The document discusses exploring the x64 architecture, covering topics such as the x64 application binary interface, memory layout differences between x86 and x64, API hooking and code injection techniques for x64, and differences in system calls between x86 and x64. It provides an overview of key technical details and concepts for developers working with x64 platforms.
The document discusses Oracle database logging and redo operations. It describes how Oracle uses physiological logging to generate redo records from change vectors. Change vectors transition database blocks between versions. Redo records group change vectors and transition the overall database state. The document provides an example redo record for an INSERT statement, showing the change vectors for both the table and undo segments involved in the transaction.
1. The document describes how Oracle allocates CU blocks and CR blocks in the buffer cache when updating column values from A to I through consecutive commits.
2. It shows the expected outcome of 6 CR blocks being allocated for the 6 updates before a new CU block is needed.
3. Using a tool to view the internal Oracle buffer cache, it demonstrates this expected behavior, showing the CR blocks and CU blocks allocated for updates from A to I.
Compiling Imperative and Object-Oriented Languages - Garbage CollectionGuido Wachsmuth
The document discusses garbage collection techniques. It describes mark and sweep garbage collection, which involves two steps: 1) marking all reachable records from program roots like variables; and 2) sweeping through and deleting any unmarked records. Reference counting is also covered, where records with a reference count of 0 are deleted. Copy collection and generational garbage collection are briefly mentioned.
Dbms plan - A swiss army knife for performance engineersRiyaj Shamsudeen
This document discusses dbms_xplan, a tool for performance engineers to analyze execution plans. It provides options for displaying plans from the plan table, shared SQL area in memory, and AWR history. Dbms_xplan provides more detailed information than traditional tools like tkprof, including predicates, notes, bind values, and plan history. It requires privileges to access dictionary views for displaying plans from memory and AWR. The document also demonstrates usage examples and output formats for dbms_xplan.analyze.
1. The COBOLBinaryHelper loads COBOL data from SequenceFiles and parses the bytes into a structured record based on the provided COPYBOOK.
2. The record contains the raw COBOL field values as bytearrays as well as parsed versions as strings and arrays.
3. Pig UDFs can then operate directly on the parsed fields to analyze and transform the COBOL data.
The document describes the steps to build a mechanically scanned LED clock called "The Propeller Clock". It uses a DC motor to spin a circuit board with LED digits. The motor's armature is used to power the circuit board. A PIC microcontroller is programmed to control the LED display and keep time. Modifications are suggested to adapt it to different motors.
The Ring programming language version 1.9 book - Part 68 of 210Mahmoud Samir Fayed
This code defines a GraphicsApp class that uses RingOpenGL and RingAllegro to render multiple textured cubes. The class loads bitmap textures, sets up the OpenGL viewport and projection matrix, and draws cubes with different textures applied. It rotates the cubes over time and handles user input and redraw events to animate the scene.
The document contains SQL commands that create tables, insert data, and perform queries on the tables. The tables created are studies, software, and programmer. Data is inserted and various queries are run to retrieve, aggregate, and analyze the data. Key information summarized includes:
- Tables were created to store student studies data, software project data, and programmer details.
- Data was inserted into the tables and various queries were run to retrieve, calculate statistics on, and analyze the data across the tables.
- Queries included finding averages, minimums, maximums, counts, sums, and using functions like trunc, round, and to_char to manipulate dates and strings.
This document provides an overview of memory management in the kernel, including:
1. The bootmem allocator is used initially by the kernel to manage memory, using a bitmap to track free/reserved pages.
2. Later, the buddy system is used to manage memory, tracking more complex page statuses using struct page.
3. Memory is divided into zones like Normal and Highmem, with boundaries defined differently on x86 and ARM architectures.
MySQLinsanity! This document provides an overview of Stanley Huang's MySQL performance tuning experience and expertise. It begins with introductions and background on Stanley Huang. It then discusses the typical phases of MySQL performance tuning projects, including SQL tuning and RDBMS tuning. Specific tips are provided around topics like slow query logging, index usage, partitioning, and server configuration. The document concludes with an invitation for questions.
This document contains assembly code for initializing an LCD display and related hardware on a microcontroller. It defines constants for LCD cursor positioning and characters for displaying volume levels and note lengths. It includes functions for resetting the LCD cursor, moving the cursor left and right, and setting the cursor position. It handles a complication where position 64 wraps to 84, to ensure proper cursor positioning.
This document provides an introduction to cost based optimization. It discusses key concepts like selectivity, cardinality, histograms, and correlation issues. The author is Riyaj Shamsudeen, an Oracle expert with 18 years of experience. Sample code and examples are provided to illustrate how to calculate selectivity and cardinality accurately to improve query optimization. Extended statistics are highlighted as a way to address correlation between column predicates in Oracle 11g and above.
The Ring programming language version 1.5.3 book - Part 68 of 184Mahmoud Samir Fayed
This document describes code for rendering multiple textured cubes in 3D using RingOpenGL and RingAllegro. It defines a GraphicsApp class that initializes OpenGL and Allegro, loads three bitmap textures, and contains functions to draw the scene with multiple cubes, apply rotations, and handle events. The cubes are drawn by binding each texture and rendering the six faces of each cube with texture coordinates. Rotations are applied around the X, Y and Z axes each frame to animate the scene.
The document discusses IO subsystem architecture in Linux. It contains 3 layers: block layer, DM layer and request queue/elevator. The block layer handles generic block IO requests and completion events. The DM layer consists of components like LVM2 and EVMS. The request queue schedules requests using algorithms like deadline and anticipatory. It also contains probes and tracepoints to monitor IO events.
This document provides information on advanced root cause analysis techniques for VMware ESX environments. It discusses log file locations and purposes, how to increase logging levels for specific drivers to provide more debug information, listing and setting loadable module parameters, setting up serial logging and remote syslog, and forcing crashes to collect memory dumps. The document aims to equip support engineers with tools and techniques for thorough troubleshooting when initial logs are insufficient.
VMware’s Nathan Small who works as a Staff Engineer at Global Support Services has put together a great presentation about Advanced Root Cause Analysis. The presentation was designed to give you more insight into how a VMware Technical Support Engineer reviews logs, gathers data and performs in-depth analysis. Nathan is hoping to show you the skills they’re using every day to help determine the root cause for an issue in your environment. With this core knowledge, you will become more self-sufficient within your own environment and be able to diagnose an issue as it occurs rather than after the damage has been done.
OSDC 2017 - Werner Fischer - Linux performance profiling and monitoringNETWAYS
Nowadays system administrators have great choices when it comes down to Linux performance profiling and monitoring. The challenge is to pick the appropriate tools and interpret their results correctly.
This talk is a chance to take a tour through various performance profiling and benchmarking tools, focusing on their benefit for every sysadmin.
More than 25 different tools are presented. Ranging from well known tools like strace, iostat, tcpdump or vmstat to new features like Linux tracepoints or perf_events. You will also learn which tools can be monitored by Icinga and which monitoring plugins are already available for that.
At the end the goal is to gather reference points to look at, whenever you are faced with performance problems.
Take the chance to close your knowledge gaps and learn how to get the most out of your system.
This presentation discusses new features and changes introduced in Oracle Database 11g. It provides snippets of SQL code demonstrating features such as error logging, transaction safety settings, hashing functions, and list aggregation. It also covers real-time SQL monitoring and optimization.
Secrets of building a debuggable runtime: Learn how language implementors sol...Dev_Events
Bjørn Vårdal, J9VM Software Developer, IBM, @bvaardal
New language runtimes appear all the time, but most of them die young. Failure can be attributed to
different reasons, but an important factor is that lack of support can limit the community’s and
industry’s willingness to adopt the new language.
Quicker development and improved serviceability allows emerging languages to overcome this obstacle.
By building on the proven technology available in Eclipse OMR, language developers can get more than
performance and stability; you also get tools that help you quickly debug your language runtime,
allowing you to provide competitive serviceability.
From this presentation, you will learn how to enable Eclipse OMR’s mature debugging features in your
language runtime, and also how Eclipse OMR can assist with development and debugging
1. The document describes various Moshell commands used for managing RBS nodes.
2. The acc 0 manualrestart command is used to restart the RBS node, while the pol 5 5 command polls the node every 5 seconds to check when the MO service is ready after restart.
3. Other commands described are for checking CV configuration (cvcu, cvls), managing CVs (cvset, cvmk, cvrm), and accessing measurement data (st mme, ue print).
The document discusses exploring the x64 architecture, covering topics such as the x64 application binary interface, memory layout differences between x86 and x64, API hooking and code injection techniques for x64, and differences in system calls between x86 and x64. It provides an overview of key technical details and concepts for developers working with x64 platforms.
The document discusses Oracle database logging and redo operations. It describes how Oracle uses physiological logging to generate redo records from change vectors. Change vectors transition database blocks between versions. Redo records group change vectors and transition the overall database state. The document provides an example redo record for an INSERT statement, showing the change vectors for both the table and undo segments involved in the transaction.
1. The document describes how Oracle allocates CU blocks and CR blocks in the buffer cache when updating column values from A to I through consecutive commits.
2. It shows the expected outcome of 6 CR blocks being allocated for the 6 updates before a new CU block is needed.
3. Using a tool to view the internal Oracle buffer cache, it demonstrates this expected behavior, showing the CR blocks and CU blocks allocated for updates from A to I.
The document discusses cracking pay TV systems by analyzing the Digicipher 2 conditional access system used in satellite and cable networks. It provides details on the MPEG transport stream, encryption methods, and service information tables used by Digicipher 2 to control access. Methods discussed include capturing signals with USB tuners, decoding service information tables in the transport stream, analyzing encryption keys and algorithms by disassembling firmware from the access control processor.
Kernel Recipes 2013 - Deciphering OopsiesAnne Nicolas
The Linux kernel is a very complex beast living in millions of households and data centers around the world. Normally, you’re not supposed to notice its presence but when it gets cranky because of something not suiting it, it spits crazy messages called colloquially
oopses and panics.
In this talk, we’re going to try to understand how to read those messages in order to be able to address its complaints so that it can get back to work for us.
This document provides an overview of the 8051 microcontroller including its memory architecture, registers, ports, timers, and interrupts. It describes the 8-bit data width and 8-bit addresses of the 8051. It outlines the different memory types including program memory, internal data memory, and external data memory accessed via the DPTR register. It details the specialized function registers and how to access specific bits via sfr and sbit. It explains timer operation using TMOD and TCON registers and how to write interrupt service routines in C. It also covers interrupt priorities, re-entrant functions, and using external interrupts.
This document provides configuration steps for distributing BFS in-band data over a Gigabit Ethernet network using a Scientific Atlanta DCM 9900 digital content manager. Key steps include configuring the DCM 9900 to output each BFS source as an individual SPTS with a unique multicast IP address. On the DNCS, a multicast session is defined for each BFS source using the GQAM and configured IP address. Routers are configured for IP multicast routing and IGMP. Testing verified guide, PPV, and application data but image downloads failed due to a known defect when using OSM automux across multiple frequencies.
1. The document discusses Oracle RAC Cluster Synchronization Services (CSS) and how it handles split-brain situations when network failures occur.
2. CSS uses services like Group Management and Node Monitoring to manage cluster membership and detect node failures. It relies on voting disks to resolve split-brain situations when nodes cannot communicate over the network.
3. During a split-brain, the CSS reconfiguration process attempts to keep the largest surviving subcluster alive by exiling nodes from the smaller competing subclusters. It does this by checking network and disk heartbeats as well as voting information stored on voting disks.
This document provides instructions for configuring Jumbo Frames on various Cisco and VMware networking devices. It discusses setting the MTU on Nexus switches, ACI fabrics, UCS Fabric Interconnects, and VMware vSwitches. It also provides examples of checking the MTU configuration and performing jumbo frame tests to validate the end-to-end network configuration supports larger frame sizes.
The document discusses optimization of Real Application Clusters (RAC) in Oracle 12c. It provides background on the author and outlines common root causes of RAC performance issues such as CPU/memory starvation, network issues, and excessive dynamic remastering. The document then presents golden rules for RAC diagnostics including avoiding focusing only on top wait events, eliminating infrastructure issues, identifying problem instances, examining both send and receive side metrics, and using histograms. Specific techniques are described for analyzing wait events like gc buffer busy.
The word comes from the combination micro and processor.
Processor means a device that processes whatever. In this context processor means a device that processes numbers, specifically binary numbers, 0’s and 1’s.
To process means to manipulate. It is a general term that describes all manipulation. Again in this content, it means to perform certain operations on the numbers that depend on the microprocessor’s design.
This document describes the system startup process for Cortex-M series processors. Upon reset, the processor will fetch the main stack pointer (MSP) and reset handler address from the vector table located at address 0x0. The reset handler will then execute in privileged thread mode. Interrupts are initially disabled. The MPU is also disabled initially, allowing access to all memory regions. The document then discusses setting up the vector table and performing additional initialization steps like MPU configuration in the reset handler.
The Intel 8085 is an 8-bit microprocessor that can address 64KB of memory using an 8-bit address bus and 8-bit bi-directional data bus. It has 40 pins grouped into address, data, control, power and I/O buses. The lower 8 address bits are multiplexed with the data bus. The ALE signal separates the address and data phases. Memory access involves placing the address on the bus, asserting the RD/WR signal to read or write data, and transferring data during the last clock cycle. Interrupts are handled through dedicated pins that trigger interrupt service routines at specific memory locations.
The document provides an overview of the 8051 microcontroller architecture. It discusses the 8051 memory architecture including program memory, internal data memory, and external data memory. It describes the 8051 registers including ports, timers, interrupts, and special function registers. It provides examples of using timers and interrupts for tasks like measuring pulse widths and frequencies. It also discusses designing interfaces for sensors like accelerometers using the 8051 capabilities.
The document provides an overview of the hardware architecture of the 8051 microcontroller, including:
- The basic versions of the 8051 with varying memory sizes.
- A block diagram showing the CPU, memory blocks, ports, and peripherals.
- Memory maps and addresses of interrupt vectors and special function registers.
- Pinouts and connections for external memory and I/O devices.
WinDbg is a low-level debugger for Windows that provides features like usermode debugging, kernel debugging, post-mortem debugging, and support for debugging extensions. It can be used to debug crashes, analyze memory leaks, find deadlocks, and investigate other issues when the higher-level Visual Studio debugger is not sufficient. The document provides examples of using WinDbg commands and extensions like SOS to debug memory leaks, analyze crashes based on offset or dump files, and investigate .NET deadlocks.
Lec5 Computer Architecture by Hsien-Hsin Sean Lee Georgia Tech -- Branch Pred...Hsien-Hsin Sean Lee, Ph.D.
This document discusses branch prediction in computer architecture. It begins by explaining what information is predicted for branches - the direction and target. It then categorizes different types of branches and discusses the costs of branch misprediction. Various branch prediction techniques are presented, starting with simple 1-bit and 2-bit predictors, and progressing to more advanced correlating and global history predictors. The goal of branch prediction is to reduce penalties from mispredicted branches by speculatively executing the predicted path.
Similar to [KOR] ODI no.004 analysis of oracle performance degradation caused by inefficient block cleanout (20)
The document provides information about Amazon Aurora including:
- An overview of Amazon Aurora describing its high performance, scalability, availability and security features compared to other databases.
- Details on Amazon Aurora's architecture which uses a multi-tenant storage layer and integrates with other AWS services for backups, replication and high availability across Availability Zones.
- Descriptions of new Aurora capabilities like Multi-Master which allows applications to read and write to multiple database instances for increased availability without downtime.
This technical report discusses configuration of the Performance Schema in MySQL 5.6. It describes configuration tables for setting monitoring targets, consumers, instruments, and objects. It shows commands for checking default settings and updating configurations. Benchmarks with different Performance Schema settings show throughput decreased when instruments were enabled but wait events only configuration had less impact than fully enabling instruments.
The document outlines the agenda for the 8th demand seminar held by EXEM, including presentations on PostgreSQL Vacuum and MySQL locks. The PostgreSQL presentation covers the details of Vacuum including its behavior during updates, deletes, and different Vacuum commands. The MySQL presentation covers different types of locks in MySQL including global read locks, table locks, and string locks.
This document summarizes the results of comparing standard Vacuum and Vacuum Full operations in PostgreSQL. Standard Vacuum deletes just deleted tuple identifiers, while Vacuum Full rewrites the entire table. The summary describes how inserting, deleting, and vacuuming data affects the table size and contents as seen in the data files.
엑셈 편집부, 『그림으로 명쾌하게 풀어쓴 Practical OWI in Oracle 10g』, 엑셈(2007)
실제 Practical OWI 세미나에서 사용됐던 다양하고 상세한 그림을 그대로 사용하면서 시각적인 효과를 높이고, 상세한 설명을 통해 최대한 그림에 대한 이해를 돕도록 했습니다.
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EXEM
- 네이버 블로그: http://blog.naver.com/playexem
- Youtube 엑셈 tv: https://www.youtube.com/channel/UC5wKR_-A0eL_Pn_EMzoauJg
- Maxgauge facebook: https://www.facebook.com/yourmaxgauge/
The Building Blocks of QuestDB, a Time Series Databasejavier ramirez
Talk Delivered at Valencia Codes Meetup 2024-06.
Traditionally, databases have treated timestamps just as another data type. However, when performing real-time analytics, timestamps should be first class citizens and we need rich time semantics to get the most out of our data. We also need to deal with ever growing datasets while keeping performant, which is as fun as it sounds.
It is no wonder time-series databases are now more popular than ever before. Join me in this session to learn about the internal architecture and building blocks of QuestDB, an open source time-series database designed for speed. We will also review a history of some of the changes we have gone over the past two years to deal with late and unordered data, non-blocking writes, read-replicas, or faster batch ingestion.
The Ipsos - AI - Monitor 2024 Report.pdfSocial Samosa
According to Ipsos AI Monitor's 2024 report, 65% Indians said that products and services using AI have profoundly changed their daily life in the past 3-5 years.
06-04-2024 - NYC Tech Week - Discussion on Vector Databases, Unstructured Data and AI
Round table discussion of vector databases, unstructured data, ai, big data, real-time, robots and Milvus.
A lively discussion with NJ Gen AI Meetup Lead, Prasad and Procure.FYI's Co-Found
06-04-2024 - NYC Tech Week - Discussion on Vector Databases, Unstructured Data and AI
Discussion on Vector Databases, Unstructured Data and AI
https://www.meetup.com/unstructured-data-meetup-new-york/
This meetup is for people working in unstructured data. Speakers will come present about related topics such as vector databases, LLMs, and managing data at scale. The intended audience of this group includes roles like machine learning engineers, data scientists, data engineers, software engineers, and PMs.This meetup was formerly Milvus Meetup, and is sponsored by Zilliz maintainers of Milvus.
Beyond the Basics of A/B Tests: Highly Innovative Experimentation Tactics You...Aggregage
This webinar will explore cutting-edge, less familiar but powerful experimentation methodologies which address well-known limitations of standard A/B Testing. Designed for data and product leaders, this session aims to inspire the embrace of innovative approaches and provide insights into the frontiers of experimentation!
End-to-end pipeline agility - Berlin Buzzwords 2024Lars Albertsson
We describe how we achieve high change agility in data engineering by eliminating the fear of breaking downstream data pipelines through end-to-end pipeline testing, and by using schema metaprogramming to safely eliminate boilerplate involved in changes that affect whole pipelines.
A quick poll on agility in changing pipelines from end to end indicated a huge span in capabilities. For the question "How long time does it take for all downstream pipelines to be adapted to an upstream change," the median response was 6 months, but some respondents could do it in less than a day. When quantitative data engineering differences between the best and worst are measured, the span is often 100x-1000x, sometimes even more.
A long time ago, we suffered at Spotify from fear of changing pipelines due to not knowing what the impact might be downstream. We made plans for a technical solution to test pipelines end-to-end to mitigate that fear, but the effort failed for cultural reasons. We eventually solved this challenge, but in a different context. In this presentation we will describe how we test full pipelines effectively by manipulating workflow orchestration, which enables us to make changes in pipelines without fear of breaking downstream.
Making schema changes that affect many jobs also involves a lot of toil and boilerplate. Using schema-on-read mitigates some of it, but has drawbacks since it makes it more difficult to detect errors early. We will describe how we have rejected this tradeoff by applying schema metaprogramming, eliminating boilerplate but keeping the protection of static typing, thereby further improving agility to quickly modify data pipelines without fear.