Oracle

A partitioned index (or index partition) is primarily for a partitioned table.As the amount of data grows, the normal heap table needs to be converted to the partition table, and its index is converted to the partition index accordingly.The

Today do not know how, whim, put the machine out of the domain, and then ready to oracle11g control to deal withAt the beginning, did not have any intentions, the Internet casually find a bit of information, and then dry, and then nothing to dry,

Two forms of judgment for Oracle's SQL statements Determine the current column and change the current column Determine if a situation changes other values A kind of case in detail: the realization is that when the value of NUM

To bring Excel to the Oracle database, I now know that one way is to:1. Save Excel as a CSV file2. In PL/SQL developer, the contents of CSV file are directed into OracleExpand Next Step 2:1. Open PL/SQL Developer, log in to database2. Tools-Text

Oracle the user security management mainly has permissions and RolesWhen the user was just created. The user does not have any rights or permissions and cannot run whatever action.Assuming that you want to run a specific database operation, you

SQL statement ClassificationSelect query statement??DML statement (Data manipulation language) Insert, Update, Delete, Merge??DDL statements (data definition language) Create, Alter, Drop, Truncate??DCL Statement (Data Control Language) Grant,

Usage examples:--Select columns for the entire table1. Select* fromEMP;--Select the contents of the specified columnSelectJob fromEMP;SelectEname,sal fromEMP;--Conditional JudgmentSelectSal fromEMPwhereSal= -;--between and methodsSelect*

To create a table:1 --To Delete a table:2 --Delete the existing table with the same name before creating the table, ensuring that you can create a success. 3 --but this is a very dangerous operation and it can be very bad to delete a table that

Commonly used Oracle database operation statements, the following is for reference only:First, query1. Query the number of all data bars for a database table that is greater than a certain dateSelect COUNT (*) from Alarm_log t where

--Create a data fileCreateTablespace--Create a table space and create a data file at the same timeCreate TemporaryTablespace--Create a temporary data file while creating a temporary table spaceAlterTablespace ...AddDataFile--to add a data file to a

Summary of date functions: System time Date operation First, the system timeSysdate: Or Western format, we generally need to_char (date, ' Yyyy-mm-dd hh24:mi:ss ')Next_day: The date of the next week of the current dateExample: the date of

Oracle built-in functions are divided into four main categories: numeric functions Character functions Date function Conversion functions This analytical numerical function:First, rounding roundRound (DOUBLE,M)Double: we want to

Statement:TableName Oldcname Newcname; --Modify field namestableNameModify (cloumnname data type ); --Modifying data typesFor example:1. Create a table:CREATE TABLE Student (ID VARCHAR2 (+) primary key,NameVARCHAR2 (8) NOT NULL,Age Number);2. Modify

Category: OracleIf you want to modify the order of the fields, you can generally use the following steps:--(1) Backing up the target table dataCREATE TABLE Temp table as SELECT * from target table;--(2) Drop target tabledrop table target table;--(3)

A one-to-many relationship in development is often used, and yesterday a customer problem was asked to organize the information for all feedback tasks into a single line to show and export Excel.My database correspondence: The feedback task task

1. Benefits of Automatic data file expansion1) does not appear because there is no remaining space available to the data cannot be written2) Minimize man-made maintenance3) can be used in databases where important levels are not very large, such as

Paradigm: A rule for designing a database definition,Three paradigms, flexible use, human thought is livingA paradigm1, there is no redundant dataRecords in the same table cannot have duplicate----so the primary key (must have)2, each field must be

First, when establishing the table, pay attention to the role of pctfree parametersPCTFREE: The percentage of space reserved for a block, indicating when the data block can be insert, the default is 10, indicating that when the free space of the

1. Create userCreate user KD identified by 123456;2. Grant permission to connect to the databaseGrant connect to KD;3, the Scott User's EMP table is authorized to KD can be queriedGrant SELECT on Scott.emp to KD;Grant CREATE table to KD;4. Reclaim

Summary of merge into usage in Oracle (Source: http://www.cnblogs.com/dongsheng/p/4384754.html)causes :Some time ago, because it involves a table of big data operations, to make additions and deletions at the same time, I and master think a lot of