Oracle

In When learning Oracle, we will find that many of Oracle's knowledge points are in pairs.So, in order to facilitate understanding and memory, I will make a summary of this series.The first part of this series is:Is the initialization parameter

Navicat is A. Oracle client that connects to the Oracle server through the Oracle client. There are two types of clients, one is standard Client installationProgram,:

Syntax for adding fields: alter table tablename add (column datatype [default value] [null/not null],...); Alter table tablename modify (column datatype [default value] [null/not null],...); Syntax for deleting a field: alter table tablename drop

Environment: mysql> show variables like '%storage_engine%';+----------------+--------+| Variable_name | Value |+----------------+--------+| storage_engine | InnoDB |+----------------+--------+1 row in set (0.00 sec)mysql> select version();+-------

The environment configuration for Silent Installation is the same as that for graphical installation. Key points: ① Each response file is in the downloaded software package "/database/response /" Major: Oracle software installation, Please modify

Some people say that there is no index. What can be used to guarantee the constraint? Regardless of whether this is true or false, many restrictions (except not null) are implemented by using indexes to quickly locate constraints. The unique

(1) free A common problem is: How much memory is used by my applications, servers, users, and system processes? Or How much memory is available now? If the memory used by running processes is greater than the available Ram, you need to move these

Environment: sys@ORCL> select * from v$version where rownum=1;BANNER----------------------------------------------------------------Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prodsys@ORCL> !uname -aLinux localhost.localdomain 2.6.18-

Here is an example of comparing two dictionaries: A dictionary has an index directory (dict A), and a dictionary does not (dict B) Now we need to find out the similarities and differences between all the words starting with. So how do you compare

(I) index unique Scan For exampleIf the table has a unique index, index unique scan is used to search the index column. The original index unique scan and index range scan have the same search path on B tree. Only index unique scan stops

① Configure listener. ora Reference document b14213 (net service reference)Example of static registration on page 1The first section of page 139th Case: think = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS=(PROTOCOL = tcp)(HOST= 192.168.227.128)

(I) basis of cooperation (1)/* All null Columns cannot be stored in B * tree */hr @ orcl> Create Table T (X number, y number ); HR @ orcl> Create index idx_t on T (x, y); HR @ orcl> insert into T values (1, 1); HR @ orcl> insert into T values (1,

Next to the previous article. ③ Dike DDL commit transactions DDL pseudo code display:BeginCommit;DDL-StatementCommit;ExceptionWhen othersThen rollback;End;Therefore, DDL is always submitted, even if the submission fails. DDL is submitted at the

Every RDBMS comes out of its own SQL features based on standard SQL. Oracle is no exception. Now, let's learn about Oracle SQL.Learning SQL is used by developers to achieve excellent business logic. It is used by managers to optimize

Full offline backup, also known as cold backup. In non-archive mode, only cold backup is supported. The existence of cold backup is to protect the site, so that we can start from scratch when recovery fails. We know that the data file is the disk

In the previous blog, we know that the general process of writing redo entries into log buffer is as follows: Generate redo entry-> service process in PGA to obtain redo copy latch (multiple --- cpu_count * 2)-> service process to obtain redo

1) There are two rows in the statistics that are related to performance. 15 SQL*Net roundtrips to/from client 198 rows processed The first line indicates the number of rounds from buffer cache to PGA. The second row indicates the number of rows

The previous two articles introduced how to use collection and update collection. This article will introduce how to generate a new collection and add data to it.Procedure insert_object (d in dept_array, D2 out dept_array) is Begin -- First way to

Diagnostic file (diagnostic file)1: Role of diagnostic files Diagnostic files:Contains information about major events in the background.Used to resolve problems,Used for daily log file management.2: Classification of diagnostic file logs There are

Document directory Method 1: automatically expand the tablespace Method 2: redefine the data file size in the tablespace Method 3: add data files to the tablespace. In this way, the tablespace is added. 1: important reference Wiki 2: Oracle