Oracle

You can use indexes to accelerate data retrieval and create indexes for fields that frequently need to be queried.Oracle indexes are divided into three types:Normal: repeated data, common indexUnique: The data cannot be duplicated. It is a unique

1) The following chart represents the difference of duration for different data provider with three different row count, the odp.net take the shortest time, And bdp.net take the longest time. 2) all of three providers are based on ADO. net,

A new photo of a new person.According to the requirements of the supervisor recently, the dynamic forum should be placed on the internal website, and the for access should be changed to for Oracle. I didn't answer oracle in the past, but I thought I

Oracle, DB2, and ms SQL Server all have QueryHint, which seems to have only one. Their forms in different databases are as follows: Oracle:SELECT/* + FIRST_ROWS */* from t where (F1> 5) Ms SQL ServerSELECT * from t where (F1> 5) OPTION (FAST 10)

This article also serves as a reference for using. NET Framework. First, in JDBC:Oracle JDBC does not support executing multiple statements at a time. One solution is as follows: String str = "BEGIN ";Str + = "OPEN? For select * from emp ;";Str + =

1: Give the time, for example, "2011-7-23". query the day of the week; Select to_char (to_date ('1970-7-23 ', 'yyyy-mm-dd'), 'day', 'nls _ DATE_LANGUAGE = American') from dual; Result: Saturday Select to_char (to_date ('1970-7-23 ', 'yyyy-mm-dd'),

Map 3D and MapGuide use the FDO (Feature Data Object) technology to access a variety of Data formats without conversion, including SDF, SHP, raster Data, and SQL Server Spatial, MySql, PostgreSQL, and Oracle.   I installed Oracle 11g R1 on my

  1. CREATE PACKAGE   Create or replace package demo_mail IS ----------------------- Customizable Section ----------------------- -- Customize the SMTP host, port and your domain name below.Smtp_host VARCHAR2 (256

Comparison of some simple commands in Oracle and mysql   Oracle Mysql Comparison version Personal

The previous article Bing Maps development extension 1: Spatial Data Rendering of Oracle Spatial describes how to render Spatial data in Oracle databases, the spatial data in Oracle can be rendered in a basic graphical interface. We can also perform

The Oracle 9i server and the Oracle 10g client. Question 1:The Driver configured for NHibernate is nhib.pdf. Driver. OracleClientDriver, which is stored in the Clob and NClob fields. If the value is large, an error is returned. error messageChinese:

PGA: The Global Area of the program, the memory area used by the server process, including the data and control information of the specific server process, such as the operating system resources used. UGA: Global zone of the user, memory area used

Table, Field:Create Table TABLE_NAME ( COL1 Integer Default 4 Not Null, Constraint PK_NAME Primary Key (COL1 )); Alter Table TABLE_NAME Add ( COL2 Decimal Default 0 Null, COL3 Varchar2 (20) Default ''Null, COL4 Integer Not Null ); Alter Table

In the oracle SQL statement in clause (where id in (1, 2,..., 1000,100 1), if the clause contains more than 1000 items, an error is returned.This is mainly because of oracle's restrictions on performance. If you want to solve the problem, you can

-- Create a user and grant corresponding PermissionsCreate user test identified by "test ";Grant dba to test;Grant unlimited tablespace to test;Grant create any table to test;-- Create a tablespaceCreate tablespace SM10001Logging datafile 'd: \

Single-record functions in SQL1. ASCIIReturns the decimal number corresponding to the specified character (Note: it is a character rather than a string );SQL> select ascii ('A') A, ascii ('A') A, ascii ('0') zero, ascii ('') space from dual;A ZERO

I. Multi-table joint QueryYou can create a multi-Table query through a connection. The data queried from multiple tables can come from multiple tables, but appropriate connection conditions must exist between tables. To query multiple tables, you

ORACLE has a high-speed buffer concept. This high-speed buffer is used to store the executed SQL statements. Therefore, oracle has to do a lot of work when executing SQL statements, such as parsing SQL statements and estimating index utilization,

1. syntax structure of the stored procedure: Create or replace procedure process name Declaration statement segment; BEGIN Execution statement segment; EXCEPTION Exception Handling statement segment; END; 2. SELECT INTO STATEMENT Save the SELECT

1. To improve the robustness of the stored procedure and avoid running errors, An Exception Handling Section should be included when a stored procedure is created.2. Exceptions are PL/SQL identifiers, including predefined exceptions, non-predefined