how to use dblink in oracle sql

. If the default value of profile is not changed, the database always defaults to unlimited.4>. If both parameters are set to unlimited, the database ignores them.Password_lock_time: Specify the account contraction time after the number of failed login attempts reaches, in days.Password_grace_time: specifies the number of days before the database returns a warning. If the database password is not modified in the middle, it will expire.Password_verify_function: this field allows you to pass compl

Oracle|server The T-SQL is the language engine of Plsql, while Oracle's language engine is the same. Both of these query languages extend the ANSI SQL-92 standard to provide additional support. Almost all of the applications you create use these supplemental features. This article describes the most common, non-standar

Obtain SQL statement execution plans from the most authoritative Oracle Database This document is compiled and summarized based on relevant information. It mainly describes the most authoritative and correct methods and steps for obtaining SQL statement execution plans in Oracle databases. In addition, the meanings and

similar to the execute immediate execution process, which is not described here. [NextPage] 3. dynamic SQL statement development skills According to the previous analysis, the execution of dynamic SQL is a result of a loss of system ability in exchange for its flexibility. Therefore, it is necessary to optimize it to a certain extent. Based on the actual development experience, the author provides som

In general PL/SQL programming, SQL can be directly used in DML and transaction control statements, but DDL statements and system control statements cannot be directly used in PL/SQL, to use DDL statements and system control statements in PL/SQL, you can

Original: http://blog.sina.com.cn/s/blog_614b6f210100t80r.htmlObjective:1, do not experience the wind and rain, how can see the rainbow.2, make full use of Baidu, Google and other search engines to find data and integrate analysis!3, nothing is difficult undone!The origin of this article: the author in the study of SQL Server linked to Oracle and the

UNLOCK; GRANT "CONNECT" to "user_id"; User Password setting: ALTER USER "Cmsdb" identified by "Pass_word" Table Space creation: CREATE tablespace "Table_space" LOGGING datafile ' C:\ORACLE\ORADATA\dbs\table_space.ora ' SIZE 5M ------------------------------------------------------------------------ 1. View all current objects SQL > select * from tab; 2, the construction of a table and the same empty table

)(Sid_name = MSSQL)(Program = tg4msql)))****************************** 4. Configure tnsnames. ora in the Network \ ADMIN directory of the Oracle main directory. In my example:******************************MSSQL =(Description =(Address = (Protocol = TCP) (host = 192.168.1.180) (Port = 1521 ))(CONNECT_DATA = (SID = MSSQL ))(HS = MSSQL))****************************** 5. Restart listener. 6. Use sqlplus to

When converting an Oracle query to an SQL Server, you must be careful about some issues that are not easy to notice. We know that T-SQL is the language engine of SQL Server, while Oracle's language engine is PLSQL. Both query languages have extended the ANSI SQL-92 standard

of the Web page is relatively diversified, some web developers have low security experience, the use of a large number of Web pages related.The SQL injection of Web pages is mainly to query some sensitive information by changing the SQL query logic that the Web page sends to the background database. But often the web-linked database uses a lower user rights, and

ORACLE paging Query SQL statementThe following is a very inefficient The code is as follows Copy Code SELECT * FROM (select A.*, rownum rn from (SELECT * to Ipay_rcd_fs_return ORDER BY id DESC) A) WHERE RN This is a highly efficient The code is as follows Copy Code Select A.*, RowNum RN from (SELECT * to Ipay_rcd_fs_return ORDER BY id desc

DESC) T1) T2Order by primary key ASC For example, to retrieve 10 or 20 records from the table sys_option (primary key: sys_id), the statement is as follows:Select *From (select top 20 *From (select top 29 * From sys_option order by sys_id DESC) T1) T2Order by sys_id ASC Oralce database --------------------------------------------------------------------------------Retrieve N records from the M records in the database tableSelect *From (select rownum R, T1. * from table name T1 where rownum W

Cross-Library queries are often used when we use SQL Server and Oracle to store data at the same time. To make it easier to use cross-Library queries, one of the best ways to do this is by creating a linked server. You can create a linked server for Oracle in

Document directory PL/SQL syntax % Type of Custom Data Type Record of composite data type % Rowtype of composite data type Summary of Oracle Extended Data Types PL/SQL syntax The PL/SQL program consists of three parts: Declaration, execution, and exception handling.Template: Declare/* variable Declaration */begi

Oracle optimizer and SQL query execution sequence before Oracle executes an SQL statement, it first needs to check the SQL Execution Plan and then execute the SQL statement according to the execution plan, the optimizer executes t

not be indexed, the field has only 8 values, the index value is highly repeatable, the index selectivity is significantly lower, and therefore no index is built." However, the distribution of data values on this field is very special, as shown in the following table: Range of values The 6 7 % of total data 1% 98% 1% Moreover, in the common query, the query disposalcourseflagEighth Palm