how to use dblink in oracle sql

Book DescriptionPro Oracle SQLUnlocks the power of SQL in the Oracle database-one of the most potent SQL implementations on the market today. to master it requires a three-pronged approach: learn the language features, learn the supporting features that Oracle provides to he

Label:1, what is ODF. NE,? Oracle data Provider is specifically written for. NET (odp.net), one for the Oracle Access API for Microsoft. NET environments. Detailed explanation http://www.oracle.com/technetwork/cn/testcontent/o23odp-084525-zhs.html for the official code, no longer exists! Odp. NET you do not need to install Oracle, do not need to configure the Ora

by the business logic. Iii. Implementation Step 1 involves specific business logic, which is omitted here. Step 2: Use the BCP command of ms SQL Server to export data from ms SQL Server and use batch processing to export multiple tables (only one table is listed here). For details, see: Step 2

Oracle 10 Gb later optimizer supports two modes: Normal Mode and tuning mode. In most cases, the optimizer is in normal mode. The CBO-based Normal Mode only takes into account a small part of the Execution Plan set to select which execution plan, because it needs to be as short as possible, it is usually several seconds or milliseconds to parse the current SQL statement and generate an execution plan. There

support Oracle 9i Error: text. The table or view does not exist. Select owner, program_name from all_scheduler_programs. Some similar errors. Oralce9i does not support the method of creating a new job by right-clicking "new" in PL/SQL developer 8.0 jobs. 　　　　　　 The following text comes from the network information: PL/SQL developer 8.0 only supports new jobs cre

How to use Oracle External tables to import data from text files, oracle Text Files Recently, colleagues are busy with Data Consistency comparison. They need to compare the data in different text files. Some files are large and have many records. If they are opened in a common text editor, it is obvious that, it will be very difficult, or even cannot be opened. B

comparison (full table scan), which is determined by the database optimizer. This is the meaning of non-procedural, that is, data retrieval is determined by the optimizer, rather than by programming. When processing SQL select, update, insert, or delete statements, Oracle must access the data involved in the statement. The Oracle optimizer is used to determine t

write your own SQL tools to solve the problem:SELECT executions, disk_reads, Buffer_gets, ROUND ((buffer_gets-disk_reads)/buffer_gets,2) Hit_radio, ROUND (DISK_ reads/executions,2) Reads_per_run,Sql_text from V$sqlarea WHERE executions>0 and buffer_gets > 0 and (buffer_gets-disk_reads)/buffer_gets (17) Use Index to improve efficiency:An index is a conceptual part of a table used to improve the efficiency o

dictionary, which means more time is spent(4)Reduce access to the database: Oracle has done a lot of work internally: Parsing SQL statements, estimating index utilization, binding variables, reading data blocks, and more;(5)The ArraySize parameter is reset in Sql*plus, Sql*forms, and pro*c to increase the amount of da

,dept_name from DEPT D WHERE EXISTS (select ' X 'From EMP E WHERE e.dept_no = d.dept_no);(+)SQL statements are capitalized, because Oracle always parses the SQL statements first, converting lowercase letters to uppercase and then executing()Use the connector "+" connection string sparingly in Java code!(+)avoid using n

):Select Dept_no,dept_name from DEPT D WHERE EXISTS (select ' X 'From EMP E WHERE e.dept_no = d.dept_no); (+)SQL statements are capitalized, because Oracle always parses the SQL statements first, converting lowercase letters to uppercase and then executing ()Use the connector "+" connection string sparingly in Java cod

MySQL, MariaDB, SQL Server, SQLite, Oracle, and PostgreSQL databases in a single program. The official website is: Http://www.navicat.com.cn/products/navicat-premium. Since this machine is a 64-bit operating system, download the latest 11.1.10 64-bit version. 3, Pl\sql Developer 10.0.5.1710 PL/SQL Developer is an inte

SQL * Plus is an environment provided by Oracle for users to use SQL statements and its procedural language PL/SQL to interact with the database. It is installed with the Oracle database system. In this environment, you can

. These datatypes are not supported ed in this article. In practice, you may encounter other numeric types, such as float, integer, and decimal. These are subtypes of the four core numeric types in the preceding list. Now let's take a closer look at number and pls_integer. The number datatype. the number data-type is by far the most common numeric datatype you'll encounter in the world of Oracle and PL/SQL

Single-record functions in SQL 1. ASCIIReturns the decimal number corresponding to the specified character; SQL> select ASCII ('A') A, ASCII ('A') A, ASCII ('0') zero, ASCII ('') space from dual; A A zero space ------------------------------------ 65 97 48 32 2. CHRReturns the corresponding characters; SQL> select CHR (54740) Zhao, CHR (65) chr65 from dual; Zh C

Be particularly careful about issues that are not easy to notice when converting Oracle queries to SQL Server. T-SQL, as we know, is the language engine of Plsql, and Oracle's language engine is. Both of these query languages extend the ANSI SQL-92 standard to provide additional support. Almost all of the applications

assign permissions, if you have 100 tables you have to use 100 SQL to give permission. and SQL There are two concepts in server that are completely detached from the user and schema, and you can put those tables under a schema and then let a user have access to the schema. When you start with Oracle, you must first cr

The ORACLE tutorial is as follows: Oracle PL/SQL getting started. I. Objective of PL/SQL Structured Query Language (SQL) is a common Language used to access relational databases. It is a fourth-generation Language (4GL) and its execution features are non-procedural, that is,

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 some development skills, it should be noted that many experiences here are not limited to dynamic SQL, but also some are sui

Oracle SQL statement optimization, oraclesql statement Although orm ing is used in the project, the optimization of the Oracle system is very valuable. Here we will summarize the commonly used statements from the perspective of SQL statements. 1. Optimization in the from field:Oracle installs table data from the right