• The secret of Greenplum distributed database kernel (Part 2)


    Click to view the secrets of Greenplum distributed database kernel (Part 1) 1. Distributed actuator Now that we have the distributed data storage mechanism, we have also generated the distributed query plan. The next step is how to execute the distributed plan in the cluster and finally return the result to the user. Related concepts […]

  • [12C] database flashback and data guard


    In the data guard environment, the standby database can be opened in read-write mode by using the flashback feature of the database, which is used to perform some kind of test work on the primary database. After the test, the database can be flashed back to the previous state as a backup to continue to […]

  • [12C] switch between snapshot database and physical backup database (cloud control mode)


    This article demonstrates how to experiment with cloud control to switch between snapshot database and physical backup database. 1 switch from physical backup database to snapshot database 1) Switch to physical backup library orcldg 2) Click Convert in the standby database column 3) Click to continue 4) To confirm the conversion of the database, click […]

  • Analysis of flip 1.11 unaligned checkpoint


    As the most basic and critical fault-tolerant mechanism of Flink, checkpoint snapshot mechanism ensures the data accuracy of Flink application after recovery from abnormal state. At the same time, checkpoint related metrics are also the most important indicators to diagnose the health status of Flink application. A successful and time-consuming checkpoint indicates that the job […]

  • Common configuration of redis service (2)


    In the last blog, we talked about the configuration and description of redis’s include, network and general configuration sections. Please refer to:https://www.cnblogs.com/qiuhom-1874/p/13383166.htmlToday, we will continue to talk about the configuration and description of redis’s other configuration sections; Snapshot related configuration Save: this instruction is used to specify at least how many write operations occur in […]

  • Common basic commands of KVM management tool virsh of virtualization technology (1)


    In the last blog, we learned about KVM infrastructure and deployment, as well as the process of installing virtual machine with virt manager, a graphics management tool. Please refer to https://www.cnblogs.com/qiuhom-1874/p/13499801.html Today, let’s talk about the command-line tool virsh of KVM. Virsh has rich functions, which can manage KVM in its whole life cycle, such […]

  • Arts Week 14 | leetcode 683k empty flowerpots | redis persistence | MySQL index failure


    ARTS Arts is an activity launched by Chen Hao in the geek time column. The purpose is to keep learning through sharing. Each person writes an arts every week: algorithm is an algorithm problem, review is to read an English article, technology / tips is to share a small technology, share is to share a […]

  • Common configuration of redis service (3)


    In the last blog, we talked about the configuration of RDB persistence, secure connection and resource restriction of redis. For review, please refer to:https://www.cnblogs.com/qiuhom-1874/p/13394411.htmlToday, let’s talk about the configuration of redis master-slave replication, AOF persistence, cluster and slow log; Configuration related to replication   slaveof : this instruction is used to specify the IP address and […]

  • Business practice of JD app adapting to IOS dark mode


    The following article comes from Jingdong retail technology, the author of the research and development platform Yao Qi What is Diablo mode? IOS 13 Apple has launched dark mode, which can better protect eyesight at night and save app power consumption. However, the dark mode provided by apple only supports IOS 13. In order to […]

  • Read optimistic lock and pessimistic lock and mvcc in database


    preface In the actual use of the database, we often encounter situations in which we do not want the data to be written or read at the same time. For example, in the second kill scenario, two requests read to the system at the same time, and there is one inventory in the system, and […]

  • Sixth update of Python interview


    1. What is redis Redis is a “key value” in memory, non relational database, which belongs to NoSQL. Redis has a very fast reading and writing speed, which is especially suitable for frequent reading and writing scenarios. Redis supports master-slave replication and data persistence. 2. Do you know the common data types of redis String […]