how to use dblink in oracle sql

cannot access Oracle8 numeric fields and finds that ADO access Oracle8 is extremely slow. In order to solve the speed of using ASP to access Oracle8 and other technical problems, the author tries to use Oracle Object for OLE to access Oracle8, the result is completely Got the result I expected. Oracle Object for OLE is an important product that

lot of internal work: parsing SQL statements, estimating index utilization, binding variables, and reading data blocks; (5)You can reset the arraysize parameter in SQL * Plus, SQL * forms, and Pro * C to increase the retrieval data volume for each database access. The recommended value is 200. (6)Use the dec

Oracle SQL * Loader architecture 1. SQL * Loader architecture SQL * Loader controls the description of the entire load by an input control file, one or more data files are used as raw data, its detailed composition structure includes Input Datafiles --> Loader Control file, the original data File loaded to the database

Use sqlprofile to optimize slow SQL statements in goldengate and SQL statements In HP unix, a process is monitored to occupy a high cpu. Later, it was found that the statement execution plan in gg had a problem, resulting in a high cpu. Since the statements in gg cannot be changed, how can we change the execution plan of statements that cannot be changed? sqlprof

Label:Test environment Introduction 1, Oracleserver Database version:10.2.0 ip:192.168.1.5 Oracle_home:d:\oracle\product\10.2.0\db_1 2. Oracle Transparent Gateway Server version:10.2.0 ip:192.168.1.15 installation directory D:\oracle\product\10.2.0\tg_1 3. MS SQL Server SQL

Oracle uses TRACE for SQL Performance Analysis If the SQL _trace parameter is set to true, the entire instance will be tracked, including all processes: User processes and background processes, which may cause serious performance problems and must be used with caution in the production environment. 1. perform trace operations based on related transactions or

are different so its resource consumption must be different. At this point, there will be two identical SQL statistics in V$sql, and in V$sqlarea, the same 2 pointers will be merged, the number of executions, disk_reads, buffer_gets and other statistics will accumulate (sum), The Version_count will be shown as 2, which is the V$sqlarea aggregation effect.There are no statistics in v$sqltext , but the compl

Functions in oracle are divided into character functions, number functions, date functions, empty processing functions, conversion functions, and other common functions. The following are some SQL functions commonly used in ORACLE: lower () function content conversion LOWER case SQLSELECTLOWER (T_NAME) FROMtest_partitioning2; lower (T_NAME )------------ Functions

In general PL/SQL programming, SQL can be used directly in DML and transaction-controlled statements, but DDL statements and system control statements cannot be used directly in PL/SQL, and it is possible to implement DDL statements and system control statements in PL/SQL by using dynamic SQL.First, we should understan

1. Introduction This article focuses on the benefits of using SQL Server Integration Services to extract data from heterogeneous data sources and to import data into Microsoft®sql server™ for Business Intelligence (BI) analysis and reporting. Oracle database 10g data is used as the primary data source. Readers of this article include IT professionals, database

Oracle SQL statement Optimization 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 t

table is relatively small compared to the salary table. Therefore, if you separate the original SQL statement, first scan the employee table according to the driver conditions to obtain the required deptno information, the deptno is used as the filter condition to filter the salary table and obtain the final query result, which may achieve better query performance. First, we can use the deptno obtained fro

: Parsing SQL statements, estimating index utilization, binding variables, reading chunks, and so on; (5)The ArraySize parameter is reset in Sql*plus, Sql*forms, and pro*c to increase the amount of data retrieved per database access, with a recommended value of 200 (6)Use the DECODE function to reduce processing time:U

Oracle SQL * Plus is a client tool that interacts with Oracle. In SQL * Plus, you can run the SQL * Plus command and the SQL * Plus statement. The DML, DDL, and DCL statements we usually call are

1. select an appropriate ORACLE optimizer 2. Access Table 3. Share SQL statements 4. Select the most efficient table name sequence (only valid in the rule-based Optimizer) 5. The connection sequence in the WHERE clause. 6. Avoid '*' in the SELECT clause '*' 7. Reduce the number of database accesses 1. select an appropriate ORACLE optimizerThere are three optim

When we manually copy the entire database and specify a new dbname for the database by recreating the control file, we cannot assign a new dbid to the database. for the above problems, we can use the nid command to allocate When we manually copy the entire database and specify a new dbname for the database by recreating the control file, we cannot assign a new dbid to the database. for the above problems, we can u