Oracle

Create a table1 Create TableVacationsday2 (3Fldid Number( A) not NULL,4Fldnamevarchar2( $),5 fldbegindata Date,6 fldenddata Date,7Fldselectid Number(Ten)8);Create sequence self-increment 1 create SEQUENCE vacationsday_sequence 2 INCREMENT by 1

Here is an example of my own test environment:1. The tablespace's block_size is 8192 bytes, or 8KBytes. From the data dictionary, the max_size is 2147483645, which is about 15.9TBytes.2. When creating a tablespace, you can choose Bigfile or

To build a table statement:CREATE TABLE table1 (IDD VARCHAR2 (10),Val Varchar2 (20));CREATE TABLE Table2 (IDD VARCHAR2 (10),Val Varchar2 (20));Insert data:INSERT INTO table1 values (' 01 ', ' 1111 ');INSERT INTO table1 values (' 02 ', ' 222

Alter session set nls_date_format= ' Yyyymmdd hh24:mi:ss ';Select Sysdate from dual;Conn dbauser/123456; Just a single user, and then delete one of the tables for testing.drop table test;Rman target/startup Mount;Restore database; Restoring a data

If we need to display the results of the two SELECT statements as a whole, we need to use the union or UNION ALL keyword.Union (or union) is the function of merging multiple results together to display them.The difference between Union and union all

Log on as a system user to find the user who needs to be deleted:--Find UsersSELECT * from dba_users;--Find the path to the workspaceSELECT * from dba_data_files;--Delete UserDrop user name cascade;--Delete Table spaceDrop tablespace tablespace name

There are a lot of solutions on the net, but I do not understand, do not know what the ghost of the Thing, why a word can solve the matter, have to long-winded said the principle is what, see a face Meng ForcedMy solution into the

Keyword "purge"The drop table is not completely deleted, but is stored in the Recycle Bin.If you want to manually clear the table in the Recycle Bin, you need to use the keyword "purge". Clears the specified table: Purge table table_name;Clear the

Set val = (exists (where tab1.id = tab2.id) In this way, the TAB2 part will not be updated to TAB1, but if the TAB2 is not the value of the part, TAB1 should be empty, then the last sentence removed, changed toSet val = (where tab1.id =

This is a review of Oracle's approach to accessing table data, in an Oracle database, to access the data stored in the database,To go through the following steps in turn:Pending SQL----> Parsing----> Optimizer processing----> Generating execution

1. It is best not to correlate more than 3 table examples:Salary Table A provident Fund form b Medicare watch CIf a in the Payroll table has employee number 12365, and no 12365 data in table BIf the association condition is a. Work number =b. The

Explain the Oracle RAC time synchronization (NTP/CTSS) instance, ntpctss 1. RAC-related time synchronization (time synchronization) Oracle Grid can synchronize time in two ways 1) OS-based NTP 2) Cluster Time Synchronization Service (CTSS) based on

The new features of Oracle 12C R2 are described as many tenants and support local UNDO mode and 12 cundo In MySQL 12.1, all PDB instances can only share the same UNDO tablespace. In 12.2, they all have their own undo tablespace. This new management

(Les05 ASM Instance) [1, 20180208], les0520180208Learning objectives description use the benefits of ASM to manage the creation and deletion of ASM instances extended ASM disk groups use various utilities to retrieve the benefits of ASM metadata for

Oracle Database Synonyms I. Definition A synonym is an alias for a database solution object. The database solution objects here refer to tables, views, sequences, stored procedures, packages, and so on. 2. Benefits of synonyms 1. No memory space

(Les03 DB_DBCA) [20180206], les0320180206Objective: To Use Database Configuration Assistant (DBCA) create a database use DBCA to generate a database creation script use DBCA to manage the database design template use DBCA to execute other tasks to

Oracle: Summary of common plsql functions and oracleplsql 1. Implement Chinese-English character set conversion under SQLPLUS alter session set nls_language='AMERICAN';alter session set nls_language='SIMPLIFIED CHINESE'; 2. Operators Arithmetic

Oracle statement for batch update or database insertion 1. oracle batch update or database insertion statement: UPDATE orderWarehouse SET shippingCompanyid = # {orderWarehousePo. shippingCompanyId}, CUSTOMERSHIPPINGACC =#{ orderWarehousePo.

Explain the oracle database DML statements and explain the oracledml statements INSERT The INSERT command can INSERT a row or a set of rows created by the SELECT statement. If you do not specify the value to insert to a column, the position

How Does oracle achieve full-width and half-width switching ?, Oracle full angle Since numbers and numbers in Japanese are in full-width format, oracle may fail to process these full-width strings. Let's take a look at the conversion functions