2021/4/28 COMP9315 21T1 – Prac Exercise 01 COMP9315 21T1 Prac Exercise 01 DBMS Implementation Setting up your PostgreSQL Server Aims This exercise aims to get you to: set up your directories on the /srvr file system install a PostgreSQL database server on /srvr You ought to get it done by the middle of Week 2. […]
CS计算机代考程序代写 database file system SQL 2021/4/28 COMP9315 21T1 – Prac Exercise 01 Read More »
2021/4/28 Catalogs Catalogs Database Objects Catalogs Representing Databases Representing Tables >> COMP9315 21T1 ♢ Catalogs ♢ [0/11] cgi.cse.unsw.edu.au/~cs9315/21T1/lectures/catalogs/slides.html 1/13 2021/4/28 Catalogs ∧ >> ❖ Database Objects RDBMSs manage different kinds of objects databases, schemas, tablespaces relations/tables, attributes, tuples/records constraints, assertions views, stored procedures, triggers, rules Many objects have names (and, in PostgreSQL, some have OIDs).
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COMP9315 21T1 Exercises 01 DBMSs, PostgreSQL, Catalogs DBMS Implementation [Show with no answers] [Show with all answers] Some of these questions require you to look beyond the Week 01 lecture material for answers. Some of the questions preempt material that we’ll be looking at over the next few weeks. To answer some questions, you
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2021/4/28 Transaction Processing Transaction Processing Transaction Processing Transaction Terminology Schedules Transaction Anomalies >> COMP9315 21T1 ♢ Transaction Processing ♢ [0/12] https://cgi.cse.unsw.edu.au/~cs9315/21T1/lectures/tx-intro/slides.html 1/14 2021/4/28 Transaction Processing ❖ Transaction Processing A transaction (tx) is … a single application-level operation performed by a sequence of database operations A transaction effects a state change on the DB ∧ >>
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COMP9315 Sample Exam The University of New South Wales COMP9315 DBMS Implementation Sample Exam DBMS Implementation [Instructions] [Notes] [PostgreSQL] [C] [Q1] [Q2] [Q3] [Q4] [Q5] [Q6] [Q7] [Q8] Question 2 (10 marks) Consider the following SQL statements to create a new data type and table: create type Gender as enum (‘male’, ‘female’, ‘none of your
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COMP9315 21T1 – Exercises 01 COMP9315 21T1 Exercises 01 DBMSs, PostgreSQL, Catalogs DBMS Implementation [Show with no answers] [Show with all answers] Some of these questions require you to look beyond the Week 01 lecture material for answers. Some of the questions preempt material that we’ll be looking at over the next few weeks.
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2021/4/28 Scanning Scanning Scanning Selection via Scanning Iterators Example Query next_tuple() Function Relation Copying Scanning in PostgreSQL Scanning in other File Structures >> COMP9315 21T1 ♢ Scanning ♢ [0/16] https://cgi.cse.unsw.edu.au/~cs9315/21T1/lectures/scanning/slides.html 1/18 2021/4/28 Scanning ❖ Scanning Consider executing the query: select * from Rel; where the relation has a le structure like: This would done by
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COMP9315 21T1 Exercises 04 Implementing Sorting and Projection DBMS Implementation [Show with no answers] [Show with all answers] 1. 2. You have an unsorted heap file containing 4500 records and a select query is asked that requires the file to be sorted. The DBMS uses an external merge-sort that makes efficient use of the
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Final Examination Project Database Principle and Application Spring 2021 • Due July 16, 2021 Goal: The goal of this project is to provide a realistic experience in the conceptual design, logical design, implementation, operation, and maintenance of a relational database and associated applications. First, I shall describe the application, then the categories of requirements, and
Join ordering of SQL optimization 1.1作业背景 连接优化是数据库领域最重要的研究问题之一。给一个特定查询，连接优化任务是确定关系的连接顺序，并将其转化为物理计划，使得查询任务能够高效执行。它是关系型数据库查询优化的关键问题。 数据库传统的寻找SQL查询时的最佳连接顺序的方法有： 动态规划算法，贪婪算法，QuickPick等等… 最近有两种基于强化学习的方法，分别是： ReJOIN 和 Bao。 该项目的目的对这三种方法进行评估。 1.2 需要完成的部分 该项目共需要完成及实验评估5种方法：传统方法*3，ReJOIN*1和Bao*1。 5钟方法均已实现或找到源代码（在1.5可见），目前需要老师参照文献3中第四部分实验部分来对对这5种方法进行实验及评估。（主要是对比5种方法对JOB中不同的SQL查询语句所需要的搜索时间和执行时间）（搜索时间是指产生执行计划的时间，执行时间是指该join order执行所需的时间） （使用（文献4）中基于 IMDB (Internet Movie Database) 真实数据集 (3.6 GB, 21 个表) 的 JOB 进行测试 ，评估该优化器在PostgreSQL中的性能如何。） 1.3 需要掌握的能力 数据库 与 强化学习 最好老师也懂得数据库的连接优化问题，不过问题不大，CSDN上有不少文章很好理解。 重要：目前ReJOIN是有源代码的，Bao和DQ可以2选1进行实验，具体选哪个看觉得哪个更容易做。 1.4 文献 文献1（ReJOIN）： Deep Reinforcement Learning for Join Order Enumeration 深度强化学习，用于连接顺序枚举 https://www.cs.brandeis.edu/~olga/publications/ReJOIN_aiDM18.pdf 文献2（Bao）： Bao: Learning
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