Database Administrator

Solutions to the increasing size of MySQL ibdata1 files I encountered a MySQL database installed in yum when installing zabbix monitoring. Later I used it for a while to find that the ibdata1 space under the data Directory was very large, on the

Usage and difference of in, exists, not in, and not exists in SQL queries 1. in and exists In connects the External table to the internal table as a hash (Dictionary set), while exists loops the External table and queries the internal table after

MyCAT reports java. lang. OutOfMemoryError: Java heap space In the morning, my colleague reported that mycat was suspended again. It was estimated that the memory was still overflow and I checked the error log. INFO | jvm 1 | 07:09:06 | java. lang.

Comparison of iOS databases: SQLite vs. Core Data vs. Realm If you want to develop a great application that can quickly run without bugs, you must carefully consider all aspects of your application. There is one thing you must solve: how to store

Mysql read/write splitting implemented by mycat and mycatmysql read/writeMycat is a middleware that can be used for mysql read/write splitting, data sharding, table sharding, and disaster tolerance backup. It can also be used for multi-tenant

MyBatis DAO Layer Development-Mapper dynamic proxy method, mybatismapper SqlMapConfig. xml Mapper. xml select * from user where id =#{ id} select * from user where username like '% $ {value} %' select

How to convert a json data key-value pair into a dictionary without quotation marks? json quotation marks Zookeeper recently met a website, and the returned data is disgusting. It is very troublesome to use regular expressions or other methods to

PostgreSQL database in the year, MySQL score dropped sharply, postgresqlmysql To determine the DBMS for the year 2017, DB-Engines deducts the score for the year January 2018 from the latest score for the year January 2017 to get the score

In-depth understanding of MySQL 5.7 GTID series (1) and mysqlgtid Author:Gao Peng (Eight monsters in Chongqing) Original article address: Http://www.jianshu.com/p/87f66cdeb49c A total of 10 articles will be published this time. The source code

One thousand reasons for not using Null, Null Hong Kong, Null seems to be a headache everywhere. For example, NullPointerException, which is a headache in Java, in order to avoid the unexpected Null pointer exception, for thousands of years,

Server: Redhat Linux Enterprise 4.0 + Progress restart SP9Client: Windows XP Professional SP2First download the Merant ODBC 3.7 For Progress connector, which is the ODBC driver of Progress, after the installation is complete, you can see the MERANT 3

When I receive a credit card bill every month, I am always surprised and confused. How did I spend so much money last month? Looking at every bill, I couldn't remember where the money was spent. Think twice and take action. I want to keep an account.

Stored procedures are very powerful. To some extent, they can even replace the business logic layer. Next, we will illustrate using stored procedures to insert or update statements.1. Database Table Structure The database used is SQL Server2008.2.

1. Exp Optimization 1. Use the DIRECT and RECORDLENGTH options The DIRECT parameter defines whether to use DIRECT path (DIRECT = Y) or conventional path (DIRECT = N) for export ). Conventional path export uses the SQL SELECT statement to extract

1. select an appropriate Oracle optimizer There are three optimizer types in Oracle: A. RULE (based on Rules) B. COST (COST-based) C. CHOOSE (optional) Set the default optimizer. You can declare the OPTIMIZER_MODE parameter in the init. ora file, as

Access data through views has obvious advantages. For example, data is kept confidential, data logic independence is ensured, and query operations are simplified. However, in other words, the views in the SQL Server database are not omnipotent, and

Data backup is almost a task that every system administrator has to do every day. However, this is very tedious-if the system automatically backs up data at a fixed time every day, that would be nice! Next, I will talk about how to implement

This article is from DBAnotes. Original article title: DRBD and Pacemaker If someone asks you if a PC server can reach 99.99% high availability, what should you do? Maybe no machine can "Make sure" to achieve this availability. Of course, there may

NetApp FilersIt is certified by Oracle, Sybase, DB2, and other large database vendors and has been widely used by Fortune 1000 companies to enhance and simplify data storage and read performance. NetApp Filers complies with the standard hardware and

Exception Handling in programming is very important. Of course, exception handling in Stored Procedures in SQL statements is also very important. explicit exception prompts can quickly find the root cause of the problem, saving a lot of time. Next,