Oracle

1. How Execution plan management works1.1 Controlling the stability of the execution plan Before 11g, you can use the storage outline (stored outline) and SQL profile to pin the execution plan of an SQL statement to prevent performance

When you count a field with a null value, you find that count (1) is different from the record that is obtained by count (field).Conclusion: 1.count (1) is consistent with the result of Count (*) and contains a null value.2.count (field) does not

It is well known that several result set collection operations commands, tested today in detail, found some problems and recorded the preparation.Suppose we have a table student that includes the following fields and data:drop table student;CREATE

In Oracle 12c, you can use sequences of and NEXTVALCURRVAL的值作为默认值，来实现列自增！One, the use of the sequence ofNEXTVALandCURRVAL的值作为默认值Create a sequenceCREATE SEQUENCE T1_seq;Build tableCREATE TABLE numberDEFAULT VARCHAR2 (());Inserting dataINSERT intoT1

One, restore the non-current log group[Email protected] primarydb]$ RM-RF redo01*[Email Protected]:~>startupORACLE instance started.Total System Global area 285212672 bytesFixed SIZE 1218992 bytesVariable SIZE 96470608 bytesDATABASE buffers 184549376

After reading this blog post, Oracle, MYSQL, SQL Server data paging query, in accordance with the company's Regionres table madePaging query statements for SQL Server:SELECT DISTINCT TOP -rr.id asID, Rr.strname asname, Rr.ntype asRes_type,

So easy! Oracle installation Configuration series six on LinuxIn the previous few, we installed the Oracle database software, created a database configuration monitoring, this is the last article of this system, Oracle Enterprise Manager

Method One,Just define the "ordinal" as a formula, and set the formula to: Get_block_property (' Block_name ', Current_record) can be implemented, or put this line of statements into the "When-create-record" trigger.Disadvantage: The line number

Oracle uses the rowid data type to store row addresses , rowID can be divided into two types, respectively, suitable for differentphysical rowids: storage ordinary table,clustered table,table partition and Subpartition,indexe,index partition and

Oracle Data Import Export IMP/EXPFunction: Oracle data import and export imp/exp is comparable with Oracle data restore and backup.In most cases, the data can be backed up and restored with Oracle data import and export (no loss of data).Oracle has

Creating Oracle Connection servers in SQL ServerThe first type: interface operation(1) Expand Server Objects-- linked Servers-- right-click on "new linked server " (2) Enter the IP of the linked server(3) After the link is successfulSecond type:

Because of Oracle's commercial copyright issues, maven cannot download the jar package directly from the central repository, and if you want to use a jar package, you need to handle it manually. The first step: Put Ojdbc14.jar in the user directory,

1. Randomly take records from the tableSELECT * FROM (SELECT * from the staff Order by Dbms_random.random) where RowNum To randomly fetch 3 records from the staff table2. Generate Random NumbersSELECT Dbms_random.          RANDOM from DUAL; produce

In the same LAN, the client can not access the remote server, and after the personal summary of the online data, the following settings are required(1) The exception must be set on the Oracle server servers:Control Panel->windows Firewall, advanced

--Oracle CLOB Operations--Created on 2015/4/8 by TianpingDeclare --Local variables hereV_clob1 Clob; V_CLOB2 Clob; V_amountInt;--lengthV_offsetInt;--Offset Amount Str varchar2( -);Begin --initial or empty CLOB

VARCHAR2 (size) variable length character type (maximum character)NVARCHAR2 (size) variable length unicode character type (maximum character)char (size) Word length character type (maximum character)Number (p,s) numeric (p is the maximum length, s

Cause of the problem:Plsql developer cannot connect to 64-bit Oracle server because Plsql is 32-bit, there is no 64-bit version, and Oracle is 64-bit incompatible.Configuration method:1, download 64-bit Oracle, extract two files, unzip the

to modify the Oracle 10g RAC Listener Port number 1523OneModify the Listener.ora to change the 1521 to 1523. Make a backup of the file in advance for quick recoveryTwoModify the Tnsnames.ora, change the remote_listener corresponding value in the

Environment descriptionOperating system: redhat6.4 64-bitOracle version: 11.2.0.4 RAC (two node)Disk array: Macro bin 3300eProblem descriptionWhen implementing a RAC cluster years ago, there is only one set of paths in the operating system where the

Install Oracle 11gR2 (11.2.0.1) and basic configuration (1) on CentOS6.0, and centos6.011gr2First install CentOS6.0. Install it. The only thing to note is the Checking the Software Requirements section in the Oracle 11G Installation guide, which