Database Administrator

Use trigger to call shell in MysSQL & MariaDB In Windows: Drop function if exists lib_mysqludf_sys_info;Drop function if exists sys_get;Drop function if exists sys_set;Drop function if exists sys_exec;Drop function if exists sys_eval; Create

Oracle: listener. ora, sqlnet. ora, tnsnames. ora configuration and example1. Solve the problem: TNS or the database cannot log on.The simplest and most effective method: use the tool netca provided by the Oracle System to configure (delete the

Application of Naive Bayes algorithm in spam filtering, Bayesian Spam I recently wrote a paper on Big Data Classification (SPAM: My tutor reminds me every day), so I borrowed several books on big data from the library. Today, I read spam in "New

Oracle local management comparison data dictionary management tablespace, oracle dictionary Locally vs. Dictionary Managed Tablespaces Organized from: http://www.orafaq.com/node/3. When Oracleallocates space to a segment (like a table or index), a

MySQL changes the table storage engine, MySQL storage engineMySQL provides multiple database storage engines that store and extract data from MySQL databases. Different storage engines have different features. Sometimes you may need to convert an

Today, a netizen asked PostgreSQL 9.0 how to debug functions in the group. I remember there was a plug-in named edb-debugger in 8.3 that could be used. there is no 9.0 database at hand, so I tested it and it could not be used at 9.1. The result is

ORA-24247: Network Access denied access control list (ACL), ora-24247aclZookeeper ORA-24247: Network Access denied access control list (ACL)Note: The command must be used under the system user.You must first use DBMS_NETWORK_ACL_ADMIN.CREATE_ACL to

Use MySQL Big Data Limit, mysql DATA limit Today, I am very surprised that the performance of the same function in MySQL varies by order of magnitude. First look at the unique id key index title of the ibmng (id, title, info) table. Let's take a

Centos Redis installation + Remote Access + startup, centosredis 1. Install redis 1. Download The redis installation package Go to the official website http://redis.io, you can also through the wget command cd /usr/local/soft/wget

Seven Tips for improving MySQL performance: mysql Performance Original article: 7 keys to better MySQL performanceAuthor: Peter ZaitsevTranslator: Peter Note: As the size and load increase, MySQL performance tends to decline. Remember these

How to convert Access to SQL database, and convert access to SQL database First of all, I am talking about the conversion between ACCESS2000 and SQL2000, and I have not tried any other products yet. I hope you can experiment more and there is

The learning progress is a little slow. I finally succeeded in installing the Oracle 11g R2 database on the Red Hat Enterprise Linux 5.5 system on the Virtual Machine. Here I will share my installation experience with you! Of course, the level is

Pub/Sub publish and subscribe, pubsub publish and subscribeRelated commandsPSUBSCRIBEPUBLISHPUBSUBPUNSUBSCRIBESUBSCRIBEUNSUBSCRIBEPub/SubSUBSCRIBE, UNSUBSCRIBE and PUBLISH implement the Publish/Subscribe messaging paradigm where (citing Protocol)

Learn SQLSTATE, sqlstate08001 1. What is SQLSTATE? Shell> SELECT * FROM no_such_table; ERROR 1146 (42S02): Table 'test. no_such_table 'doesn' t exist Display after an error occurs in the preceding SQL statement. 1146 is the error code defined by

SQL is required. Take notes. Chapter 2 describes advanced SQL features. SQL is required.22.1 Constraints To correctly design a relational database, you need to ensure that only valid data is inserted in the table. For example, if the Orders table

Troubleshooting of Logon failures when su switches to sqlplus in Oracle, oraclesqlplusProblem description:The oracle database in the production environment suddenly fails to log on, and the oracle database in the rlwrap production environment

SQL Server trigger and SQL Server triggerA trigger is a special type of stored procedure, which is different from the stored procedure we introduced earlier. A trigger is triggered by an event and automatically called for execution. The stored

Perhaps the most common error found in application code is a query request that uses a non-parameter special query to request data from the database instead of a prepared query or program. If you do not prepare your query or do not use the stored

As we all know, Oracle time can be directly used for addition and subtraction operations, such Select sysdate, sysdate-2 from dual"SYSDATE" "SYSDATE-2"-----------------------------------"19-5-09" "17-5-09" Obviously, sysdate-2

To ensure data consistency, Oracle uses the UNDO record to retrieve database data, oracle always enables users to only view submitted data or data at a specific time point (select statement time point), and the UNDO record will be stored in the