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In order to explore the mystery and greatness of Hive, we embarked on the road of learning Hive, the good and bad of this tool, let alone install Hive first... We use MySQL to store Hive's metadata Metastore, so install MySQL first. The specific ...

In Spring framework, we often use @Transactional annotation to do transactions, but transactions do not guarantee validity; The following are the problems I have encountered, which are not necessarily correct, and can be used as a reference. Ma ...

First look at a chestnut EXPLAIN select * from employees where name > 'a'; If using name index to find data needs to traverse the name field joint index tree, and then according to the traversed primary key value to the primary key index tree to find the final data, the cost is higher than the full table scan. Overlay index optimization c ...

Preface How should we investigate and analyze Mysql deadlock? There was an insert on duplicate deadlock problem on the line before. Based on this deadlock problem, this paper will share the process of investigation and analysis, hoping to be helpful to everyone. Deadlock case recovery Table structure: CREATE TABLE `song_rank` ( `id` int(11) N ...

A master once said that he knows the database he manages as well as his wife. Personally, he thinks it contains two aspects of understanding: 1. At the level of stability, more attention is paid to high-level measures such as high availability, separation of reading and writing, load balancing, disaster preparedness management and so on. 2. A ...

Catalog 1. Introduction 2. Custom Annotations 2.1 Definition 2.2 Test 2.3 Summary 3. Notes on Handwritten Transactions 3.1 maven dependence 3.2 Configure spring.xml file 3.3 Customize transaction annotations (by reflecting annotations on ...

Introduction: Openstack is an implementation of the IAAS architecture (infrastructure as a service), and OpenStack is an implementation of the IAAS architecture by NASA (National Aeronautics and Space Administration) A free software and open source project developed in collaboration with Rackspace and licensed under the Apache license.The foll ...

Case: Create database index_test, create two data tables test_table1 and test_table2 in index_test database according to the structure of the following table, and complete the basic operation of the data table according to the operation process. (1) ...

Hotel Room Management System Hotel Room Management System mysql Database Creation Statement oracle database creation statement of hotel room management system SQL Server database creation statement for hotel room management system Hotel ...

I. Detailed Framework Scrapy is a popular python event-driven network framework written by Twisted, which uses non-blocking asynchronous processing. [1] The role of internal components ** Scrapy Engine (scrapy engine): ** is used to control the ...