Oracle

Create or replace procedure updatetestdata is J number; dept_min_no number; dept_max_no number; begin -- Update the Department table Delete from test_dept; for I in 1 .. 10 loop insert into test_dept (dept_name, f_deleteflag) values

A database is a shared resource used by multiple users. When multiple users access data concurrently, multiple transactions can access the same data simultaneously in the database. If concurrent operations are not controlled, incorrect data may be

Since 64-bit oracle is installed on Vista x64 on the local machine, when trying to use PLSQL developer to access it, it is reported that the OCI. dll file cannot be loaded. Originally, OCI. dll was 64-bit and 32-bit.ProgramPLSQL developer cannot

Sqlserver, which is implemented using rank, and row_number, Where the equal data of rank orderby is generated with the same sequence number, When the row_number () order by field is equal, it is still a different auto-incrementing sequence number.

After several days of data synchronizationProgramIt is a waste of writing, because Oracle's database online backup function is already quite powerful. However, the key point is that our application scenario is very different from online backup.

Wmsys. wm_concat: Depends on wmsys users. It may not be used in different Oracle environments. The return type is clob. After intercepting the length of substr, to_char is converted to the character type. Listparts: A function provided by 11g2. It

14. How to Create a backup control file? Answer: Alter database backup control file to trace. 15. How many statuses does the database normally start? Answer: startup nomount-start the database instance Startup Mount-Database loading Startup

Instance description Data Table Structure (primary key in red) ==>Master table: test_part_cost_tab (item table)Part_no varchar2 (20)Part_name varchar2 (50) Slave table: test_part_cost_dt_tab (item cost table)Part_no varchar2 (10)Cost_id varchar2

Improves query efficiency by specifying an index for Oracle queries One 16 million data table-text message upstream table tbl_sms_moStructure:Create Table tbl_sms_mo(Sms_id number,Mo_id varchar2 (50 ),Mobile varchar2 (11 ),Spnumber varchar2 (20

Rowid and rownum are both virtual columns, but they have different meanings. Rowid is a physical address used to locate the physical storage location of specific data in Oracle, while rownum is the sorting of SQL output results. The differences are

Rowid and rownum are both virtual columns, but they have different meanings. Rowid is a physical address used to locate the physical storage location of specific data in Oracle, while rownum is the sorting of SQL output results. The differences are

In Oracle, sequence is the so-called serial number, which is automatically increased every time it is obtained. It is generally used in places where the sequence numbers need to be sorted.1. Create SequenceFirst, you must have the create sequence or

When the Oracle table is locked, other personnel may not be able to edit the relevant information, causing serious application crash. How to deal with table deadlock? 1. query the locked table;Select/* + rule */. sid, B. owner, object_name,

1. Open the powerdesigner -- file -- reverse engineer -- Database 2. Select the version of the database to be connected. Oracle version 11g is used here. 3. Click the red area and select the data source. 4. Select modify 5. Enter your database

What operations does Oracle perform when we submit an SQL statement?Oracle assigns a server process to each user process: service process (dedicated server and shared server should be distinguished in actual situations). When service process

(1) Oracle field addition Syntax: alter table table_name Add (column_name column_type); Comment: table_name: Table Name Column_name: field name Column_typeto field type; Example: alter table student add (age Number (5 )); (2) oracle adds non-null

This article was slightly modified by the gototop root baiyufeng article. Http://www.ncn.cn/Oracle zookeeper has the following modes:0: None1: NULL2: Row-s row sharing (RS): Shared table partition, sub share3: Row-x row percentage (RX): used for row

1./* + all_rows */ It indicates that the overhead-based optimization method is selected for the statement block, and the optimal throughput is obtained to minimize the resource consumption. For example: Select/* + all + _ rows */emp_no, emp_nam, dat_

1. delete a tablespace Drop tablespace tablespacename [including contents [and datafiles] 2. delete a user Drop user user_name Cascade 3. Notes for deleting a table When deleting all data in a table, the truncate table name must be used. Because

As we all know, generally, the operating system provides a method to regularly execute tasks. For example, the UNIX platform provides the crontab command for the system to periodically execute tasks. However, for some requirements, such as database