- Lock-based and timestamp-based protocols are two main approaches for concurrency control in database systems to achieve atomicity, consistency, isolation, and durability (ACID) properties of transactions.
- Lock-based protocols use locking mechanisms to control concurrent access to data and can cause deadlocks between transactions waiting for locks. Timestamp-based protocols assign timestamps to transactions and check for conflicts based on timestamp ordering to guarantee serializability without waits but lack recoverability.
- Deadlocks are addressed through prevention, detection using wait-for graphs, and resolution by rolling back the minimum number of transactions to break cycles while avoiding starvation.
The document discusses different types of indexing and hashing techniques used in databases. It covers ordered indices like B-trees and B+ trees, which store search keys in order. It also covers hashing techniques like static hashing and dynamic hashing using extendable hash structures. The document provides examples of how these indexing structures work and compares the performance and characteristics of ordered indexing versus hashing. Bitmap indices are also introduced as an efficient technique for multi-attribute queries.
- Lock-based and timestamp-based protocols are two main approaches for concurrency control in database systems to achieve atomicity, consistency, isolation, and durability (ACID) properties of transactions.
- Lock-based protocols use locking mechanisms to control concurrent access to data and can cause deadlocks between transactions waiting for locks. Timestamp-based protocols assign timestamps to transactions and check for conflicts based on timestamp ordering to guarantee serializability without waits but lack recoverability.
- Deadlocks are addressed through prevention, detection using wait-for graphs, and resolution by rolling back the minimum number of transactions to break cycles while avoiding starvation.
The document discusses different types of indexing and hashing techniques used in databases. It covers ordered indices like B-trees and B+ trees, which store search keys in order. It also covers hashing techniques like static hashing and dynamic hashing using extendable hash structures. The document provides examples of how these indexing structures work and compares the performance and characteristics of ordered indexing versus hashing. Bitmap indices are also introduced as an efficient technique for multi-attribute queries.
This document discusses multilayer perceptrons (MLPs), also known as neural networks. It covers the architecture of MLPs including fully connected layers and commonly used activation functions. It also discusses error functions like mean squared error and cross-entropy that are used in MLPs to optimize weights during training. Gradient descent is introduced as an algorithm to apply to MLPs for optimizing weights to minimize the error function.
Coursera Machine Learning으로 기계학습 배우기 : week1Kwangsik Lee
필자가 코세라 강의를 정주행 하였는데 학습과정에서 한글로 정리한 슬라이드를 공유할까 합니다. 목적은 영어로 강의하는 코세라 강의를 보실 때 참고하시거나 강의를 따로 안보시더라도 슬라이드 내용만으로도 참고하시면 좋을듯 합니다.
온라인 발행물로는 아래 링크 참고하시면 됩니다.
http://www.kwangsiklee.com/2017/07/corsera-machine-learning-week1-%EC%A0%95%EB%A6%AC/
This document discusses multilayer perceptrons (MLPs), also known as neural networks. It covers the architecture of MLPs including fully connected layers and commonly used activation functions. It also discusses error functions like mean squared error and cross-entropy that are used in MLPs to optimize weights during training. Gradient descent is introduced as an algorithm to apply to MLPs for optimizing weights to minimize the error function.
Coursera Machine Learning으로 기계학습 배우기 : week1Kwangsik Lee
필자가 코세라 강의를 정주행 하였는데 학습과정에서 한글로 정리한 슬라이드를 공유할까 합니다. 목적은 영어로 강의하는 코세라 강의를 보실 때 참고하시거나 강의를 따로 안보시더라도 슬라이드 내용만으로도 참고하시면 좋을듯 합니다.
온라인 발행물로는 아래 링크 참고하시면 됩니다.
http://www.kwangsiklee.com/2017/07/corsera-machine-learning-week1-%EC%A0%95%EB%A6%AC/