Database Administrator

A scenario of database index failure: Analysis of the Problem ideas and strategies, index analysis problems This is a problem about database index failure discovered by the company's R & D team. Our engineers analyzed and solved the problem and

What are the Mysql data types? As a DBA, when learning any database, in addition to understanding the operating principles of the database, the most basic is the data type defined by him: Oracle data type. If I am not familiar with it, I will

[MySQL Notes] MySQL index use scenarios and the SQL types that actually use indexes, mysqlsqlThis note mainly records the MySQL index content, which can be used as a reference for SQL Optimization in actual work. 1. Why are indexes used?Without an

Oracle cold backup and oracle backup Prerequisites for cold backup:The operating system is the same. You can execute scripts from Win32 to Win64 and from Win32 to Win64.Procedure:A. view the control files, data files, and log files of the two

Functions of different Oracle Patchset files, In the Patchset of Oracle 10g version, only one file Disk1. the size of the Patchset in Oracle 11.2.0.2 and 11.2.0.3 is greatly increased. The Patchset of 11.2.0.2 and 11.2.0.3 is 5 GB. These 5 GB files

[Oracle] export ledba29 The backup wocould be marked as obsolete., obsolete You defined the rediscovery Manager (RMAN) retention policy to rediscovery Window of 7 days by executing the following command: RMAN> configure retention policy to recovery

Oracle deletes all objects (tables, views, triggers, stored procedures, and functions) of the current user.Zookeeper  DECLARE TYPE name_list is table of VARCHAR2 (40 ); TYPE type_list is table of VARCHAR2 (20 ); Tab_name name_list: = name_list

Install mysql in windows and windowsmysql1. First, we need to download a mysql instance. Find the official elasticsearch download page and click the link to open it. Then we can find several types of data:MySQL Enterprise Edition,MySQL Cluster

05. Linear table (4) chain storage structure. Static linked list, linear chainChain Storage Structure-static linked listI. Static linked list1. Static linked list Storage StructureA single-chain table is implemented through pointers, but we can also

Analysis on Redis implementing lock mutex resource access and redislock mutexRedis is a popular open-source key-value database. At present, ruisi's background architecture adopts a combination of Redis and MySQL on the database layer. Redis is

Oracle learning-dmp file (table) Import and Export, oracledmpPreface   We still use a lot of dmp files, which are used as the file format for oracle Import and Export tables. Today we will learn how to export and import dmp files.  Dmp File Export  

[Non-critical data file loss (data file loss can be performed offline)-restore-1], key offlineNon-critical data file loss (loss of offline data files ):Run {SQL 'alter database datafile <> offline ';Restore datafile <>;Recover datafile <>;Slq 'alter

Compile and install dbproxy altas and compile dbproxyaltas Preface: there are already many mysql middle layers, such as dbproxy of baidu, tddl of taobao, corba of 126 and alibaba, altas of 360, mysql-proxy, oneproxy of Lou fangxin, and dbproxy of

Database: Table Structure and Data Replication instance, copying instanceSolution 11.1Copy the entire table (including data without primary key index): old_table ---> new_tableCreate table new_table SELECT * FROM old_table;1.2Copy the entire table

MySQL (Part 5) and mysql (Part 5)Common operators 1. Arithmetic Operators Operator Function + Addition operation - Subtraction * Multiplication / Division % Remainder operation

Database Course Design recontinued, database Course DesignThe coffee sales management system adds a table bill2 to solve the problem that a user corresponds to multiple products. However, after writing the table, several redundant items are found,

Mysql JDBC interface programming and mysqlJDBC Interface ProgrammingThe relationship between the JDBC interface driver package version of mysql and the mysql version can be found on the official website. For specific examples, see the following.

Import fixed format txt text data to the SQL Server database, servertxt When the amount of text data is large, it is basically impossible to input a single piece of data. It is also very troublesome to write a program to transfer it. Fortunately,

SQL statements Delete primary keys, change primary keys, delete duplicate columns (Multi-column combination), and SQL multi-Column-- Alter table HistoryData drop constraint PK_HistoryDataAlter table HistoryData add constraint PK_HistoryData primary

Upda set select, mysqlupda In oracle and other databases, you can use the update wwm2 set wwm2.town = (select wwm5.town from wwm5 where wwm5.id = wwm2.id) format to update the database. However, I recently used mysql to find that it cannot be used