Database Administrator

MySQL fuzzy query: LIKE and REGEXP Modes MySQL fuzzy query provides two modes: LIKE mode and REGEXP mode.LIKE Mode The LIKE mode uses the LIKE or not like comparison operator to perform fuzzy queries. SELECT field FROM table WHERE field LIKE [not

Oracle deletes log files The syntax for deleting a log file is as follows:Alter database drop logfile member logfile_name;Note the following when deleting a log file:1. The log file group of the log file cannot be in the current status. You need to

Redis design and implementation-Sentinel Sentinel is a Redis high availability solution. It is composed of one or more Sentinel instances and can be used to monitor all the slave servers under any number of Master servers and master servers, after

Study database Notes 2. Database notes I Table and database and MYSQL database Server (table & database & mysqlserver )? A table consists of multiple rows and multiple columns of data (a table is created with a table header, and even if the table

Find problem in eXtremeDB, problemtremedb Class table1 { Char f1; Char f2; Uint4 f3; Uint4 f4; Double f5; Uint4 f6; Uniquetree Idx1; Tree Idx2; };   Steps: Step 1: find (Idx1 = (a, B), find the records; Step 2: put (f6, c ); Step 3: find (Idx1 =

The merge command in oracle is simple and practical, oraclemerge Merge command With this merge, You can execute the inserts and updates operations on a table in an SQL statement at the same time.You can use the meger statement to merge two specified

Sharp SQL2014: handling deadlocks, sql2014  In two or more tasks, if each task locks the resources that other tasks attempt to lock, this will cause permanent blocking of these tasks and lead to deadlocks. For example: Transaction A obtains the

Data replication between tables We can use insert between two tables to implement simple replication (the two tables have the same structure). The example is as follows: SQL> create table T (2 tid number (4 ), 3 tname varchar2 (10) default 'abc ', 4

Install and use memcache. 1 memcache depends on libevent brew install libevent 2 download memcache ＃wget http://www.memcached.org/files/memcached-1.4.22.tar.gz Then install configure; make install 3. Start: 'Sudo./memcached-p 11211-m 64-u shenyb-d

Use SQL server with the doscommand and SQL server with the doscommandIn general, we can use SQL server under the DOS command and use the DOS command to use SQL server as follows:1. Connect to the database server:The osql command can be used to input

Query and sqlitequery operations in sqliteThe query () method splits the select statement into several components and serves as the input parameter of the method:SQLiteDatabase db = databaseHelper. getWritableDatabase ();Cursor cursor = db. query

Oracle cascade operations, oracle-levelWhen you add a foreing key constraint, you can also specify the cascade operation type, which is mainly used to determine how to process the foreign key fields in the subtable When deleting a record in the (on

Ubuntu14.04LTS64-bit installation of Oracle11g and oracle11g Oracle does not officially state that it supports ubuntu installation. Therefore, the environment must be adjusted and prepared before installation can be successful. Ps, I tried multiple

13. Heman tree and Its Application1. definitions and principles of the Heman tree1. Path Length: The branches between one node in the tree and the other constitute the path between two nodes. The number of branches in the path is called the path

An error occurred in Suse: Access denied for user ''@ 'localhost' to &, susedenied I haven't used MySQL for a long time. The last time I installed Banq's forum system, when MySQL Administrator is used, the system prompts mysql error number 1045

Migrate AWR metadata or import it to other databases. We can migrate (import) AWR metadata to other databases, import lower versions to higher versions, generate AWR reports with later versions, and use some new features, such SQL ordered by

Oracle 12c 3 pdb pluggable test, 12 cpdb DECLAREl_result BOOLEAN; BEGINl_result: = partition (pdb_descr_file => '/u02/pdb/pdb3.xml', pdb_name => 'pdb3'); IF l_result THENDBMS_OUTPUT.PUT_LINE ('compuble '); ELSEDBMS_OUTPUT.PUT_LINE ('compatible ');

Use Django to clean up data in the database.Description of the data cleaning problem in the database: in my system, due to history and various reasons, the data recorded in the table in the database is problematic, there are repeated and incomplete

Solution: mysql_connect () is not supported. Check whether the mysql module is correctly loaded. Fault description: linux discuz installation error prompt: mysql_connect () does not support checking whether the mysql module is correctly loaded.

14. Search Overview and sequential search, and 14 Search Overview order1. Search Overview1. Search:That is, a data element (or record) whose keyword is equal to the given value is determined in the search table based on a given value ). If the table