Database Administrator

When Oracle reads the discontinuous Buffer of memory (PGA or Buffer Cache) from multiple data files in parallel, this waiting event can be seen. This kind of wait event also occurs when the restoration operation or preprocessing buffering (instead

1. easy solution for profit calculation When the product design is defective, profit calculation will be a nightmare, because the commodity purchase price is actually changed (the prices for different purchases at different times will be different),

The following statement is enabled in SQLPLUS.Commonly used: SQL> set timing on -- control display execution time statistics. Note that set time on is displayed before the SQL prompt. SQL> SET AUTOTRACE OFF -- no AUTOTRACE report is generated.

Troubleshooting IO-related wait: Determine the true importance of IO wait events: The following two real cases illustrate why the "Wait Time" and "Service Time" sections are important for analyzing database

Agent often encounters various problems during upload. Common methods are to clean up logs or secure.A script is compiled. This script applies to the single-host and RAC environments.Configure the environment variable AGENT_HOME. #! /Bin/bash $

 2: How to view SQL Execution plans without using third-party toolsSet autotrace on If the following error occurs:SP2-0613: unable to verify PLAN_TABLE format or entitySP2-0611: An error occurred while enabling EXPLAIN reportRun oraclehome \ ora92 \

So that we can make a persuasive judgment. Description Wait for "SQL * Net message from client". The SQL * Net package that receives the statement request "parse/execute. Parse the SQL * Net package. Wait for "latch free"

Cursor definition: --- Use declare -- to define a cursor and extract all data from tab_stu. cursor c_tab_stu is select * from

Mongodb is deployed on a single node. I found an 8-core, 48 GB RAM server before the National Day and ran for a week under the pressure of more than 100 concurrent servers. No data loss or excessive server load was found. However, there are still

# For advice on how to change settings please see # Http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html # *** Do not edit this file. It's a template which will be copied to # *** Default location during install, and will be

Data is the core information asset of an enterprise. The importance of ensuring data integrity, availability, and security to the normal operation of the enterprise is self-evident, and the database is the core software that carries this important

I. Purpose When maintaining the SQL Server database, when the boss asks us to move dozens of GB of data files to other servers and requires the minimum downtime, do we have any solutions to meet these requirements? Here we assume that these two

Instances with performance impact of the cursor type. The following two cursor scripts create and execute two types of cursor: dynamic and fast forward only. Knowledge supplement: Operations in a relational database work for the entire row set. The

I have seen some posts: questions about DataReader's closure, which may seem confusing to everyone. I will explain it here: No matter what xxDataReader is, It inherits the implementation of DataReader, so there are commonalities, so the title is

Guidance:InAccess DatabaseIs embedded into a very strong database operating language-Visual Basic language, so you can use Visual Basic to write programs to implement some complex functions. The following describes how to implement encryption in the

Last year, I used DiscuzNT3.0 for secondary development and performance optimization, but I have never had the chance to write down the time relationship. Let's take a long 5.1 vacation and write an article about disruptive things. I have read the

What is Cartesian product? The implementation of cartesian products in SQL is not only Cross Join ). All join methods are converted into temporary Cartesian Product tables. Cartesian product is a concept in relational algebra, the number of rows in

Situation: multiple database servers with multiple databases on each server. The database structure is consistent and provided to different customers) 1. Manual Operation 1. Few Databases Select different databases from the drop-down list and

Skip the theory. I have introduced automatic sharding on the internet... directly go to the configuration. Please leave a message if you have any questions. Or test with million data Insert million pieces of data to a database without sharding. Data

The topics in this article are as follows: Query plan Overview Query resolution Query Optimizer Query execution Reuse of query plans Query plan Overview Most of the time, when we are using SQL server, it is very simple to do: enter an SQL