Database Administrator

Six things that MySQL should learn Because of its small size and efficient operations, MySQL is increasingly used in database applications. As an important part of LAMP or WAMP development, MySQL deserves the attention and earnest learning of PHP

Summary of Oracle hotspot table Optimization 1. Optimize the SQL related to the hotspot table. If the SQL Execution takes too long, it will hold latch for a long time. For statements with a small number of returned results, check whether indexes

Common InnoDB Parameter Parsing Common InnoDB Parameter Parsing 1. Files (data files and log files) 1. related parameters: Innodb_data_home_dir Innodb_data_file_path = file_name: file_size [: autoextend [: max: max_file_size] Note: A. The value of

Python for MySQL CRUD Python is full of operations on various databases. However, I still like this style and it involves other operations, but it focuses on database operations. Python for MySQL First, I am used to writing configuration information

MySQL error: master and slave have equal MySQL server UUIDs The MySQL error message is as follows: Last_IO_Errno: 1593 Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be

Use PL/SQL without installing the Oracle client To connect to Oracle, you often need to install an ORACLE client of hundreds of megabytes, which is very troublesome. This section describes how to connect to the oracle database by using a thin client

Guide on installing MongoDB databases in Linux Guide on installing MongoDB databases in Linux 1. Create an installer N/ Note: We generally create a mongodb user. This allows O & M to help create 2. Upload mongodb data software. N/ Annotation: Using

Use Python to send MySQL slow log emails Requirement 1Because development performs Stability Construction for a system, it is necessary to audit the slow logs of the database system and check and optimize the system. Communicate with developers by

An example of setting MySQL auto-start fault in Ubuntu Run the following command to solve MySQL self-startup in Ubuntu: # Chkconfig -- listThe program 'chkconfig' is currently not installed. You can install it by typing:Apt-get install chkconfig If

C # connect to the SQL Server database For different. NET data providers, ADO. NET uses different Connection objects to connect to the database. These Connection objects shield us from specific implementation details and provide a unified

Space occupied by Oracle computing tables In Oracle databases, how does one calculate the storage space occupied by a table? You can view the space occupied by a table in the System View DBA_SEGMENTS, USER_SEGMETNS, and DBA_TABLES, as shown

EXP-00091: Exporting questionable statistics troubleshooting When using EXP tool to export backup or migrate data, sometimes a lot of "EXP-00091: Exporting questionable statistics" error will be reported, the specific phenomenon and solution please

Status values related to MySQL query statement statistics and query Cache The status values Com_select, Queries, Questions, Qcache_hits, Qcache_inserts, and Qcache_not_cached output by 'show global status' in MySQL have been somewhat confused, now

MongoDB query timeout exception SocketTimeoutException Aggregate a collection of more than one million records. DBObject match = (DBObject) JSON. parse ("{$ match: {logType: {'$ in': [5, 9] }}}");DBObject group = (DBObject) JSON. parse ("{$ group: {'

Oracle inversion Function Oracle provides a reverse inversion function, reverse, but this function cannot be used for grouping inversion. This article provides a function that can be used for grouping inversion, as shown below: Create or replace

The content in the MySQL DATA table is case-sensitive.By default, MYSQL queries are case-insensitive, for example :? 1234567 mysql>createtable t1( ->namevarchar(10));Query OK, 0 rowsaffected (0.09 sec)  mysql>insertinto t1 values('you'),(

047-q1,Zookeeper QUESTION 1You need to load information about new MERs from the NEW_CUST table into the tables CUST and CUST_SPECIAL. if a new customer has acredit limit greater than 10,000, then the details have to be inserted into

Merge into and mergeinto Today, we have A strange demand: system A is the main system, and the terminal PDA uploads data to system. If there is A document id that can be found in system A's id, update Status; if the Document id is not found in

Mongodb error: 10061 unable to connect because the target computer is actively rejected, mongodb10061 When connecting mongodb, mongod.exestart is used first, and mongo.exe is used to connect to the database. However, the following error occurs

Causes and solutions for MongoDB query timeout exceptions Aggregate a collection of more than one million records. DBObject match=(DBObject)JSON.parse("{$match:{logType:{'$in':[5,9]}}}");  DBObject group=(DBObject)JSON.parse("{$group:{'_id':'