bind variables

What is an execution plan? The information on which the execution plan depends. An execution plan is a query solution made by the database based on the statistics of SQL statements and related tables. This solution is automatically generated by the

If you encounter some problems when using Java Date in the Oracle driver, do you want to understand what is confusing, the following articles mainly introduce the actual application solution of the Java Date issue in Oracle version drivers, to solve

Why is Oracle expdp faster than exp? What is the principle? First read the official oracle 10g documentation: Database Utilities Data Performance Improvements for Data Pump Export and ImportThe improved performance of the Data Pump Export and Import

Suggestions for improving SQL Execution efficiency: Try not to include subqueries in where; Do not write the Time query as follows: where to_char (dif_date, 'yyyy-mm-dd') = to_char ('2017-07-01 ', 'yyyy-mm-dd '); In the filter condition, the

Oracle AWR report analysis and OracleAWR Report Analysis * Definition: awr report is a performance collection and analysis tool provided by oracle at 10 Gb. It provides a report on the usage of system resources over a period of time. Through this

1. the length of a string is defined not as the number of bytes but as the number of characters (char, varchar) 2. the binary string stores the bytecode rather than the character (binary, varbinary fill, the fill value will not be removed during

 1. SqlDataRead and Dataset Selection Sqldataread advantages: fast data reading. If you do not need to process the returned data in large quantities, we recommend that you use SqlDataReader. Its performance is much better than that of datset.

Oracle 8i RAC database common error diagnostics highlights ORA-1652 to ORA-1655 Simply put, the ORA-165X error message means that the tablespace does not have enough space to allocate, so an error is reported. These errors include a ora-1652, A ora-1

When a user process connects to the database and creates a corresponding session, the Oracle service process sets a PGA zone for the user to store the relevant content of the user session. When the user session ends, the Database System

In Java, memory leaks and other memory-related issues are the most prominent in terms of performance and scalability. We have good reason to discuss them in detail.The Java memory model-or, more specifically, the garbage collector-has overcome a lot

1. Choose the appropriate Oracle Optimizer There are 3 Oracle optimizer types: A. Rule (rule-based) B. Cost (based on costs) c. CHOOSE (optional). Set the default optimizer to pass various declarations of optimizer_mode parameters in the Init.ora

First, XSSCross Site script attackA malicious attacker inserts malicious script code into a Web page, and when the user browses to the page, the script code embedded inside the Web is executed to achieve the intent of the malicious attacker.1.

1.ORACLE Optimizer total 3 kinds A, rule (rule-based) B, cost (based on costs) C, CHOOSE (optional) Set the default optimizer to pass various declarations of optimizer_mode parameters in the Init.ora file, such as

Oracle CBO RBO Detailed url:http://blog.163.com/love-love-l/blog/static/21078304201010175035270/ Http://blog.csdn.net/cnham/archive/2010/04/13/5482318.aspx First part What is Table analysis. Simply put, it is the information that collects tables

basic knowledge of PHPGo to the end of the metadata go to the beginning of the meta data Transmission Door [Basic knowledge] Type Variable Constant An expression Operator Process Control Programming Paradigm PHP is a flexible dynamic language that

Dynamic Content Summary: In the Pl/sql development process, the use of sql,pl/sql can achieve most of the requirements, but in some special cases, the use of standard SQL statements or DML statements in Pl/sql can not achieve their own needs, For

optimization | statement | execution 5th. Oracle's execution planbackground knowledge: To better carry out the following, we must understand some conceptual terms: 　　 Sharing SQL statementsIn order not to parse the same SQL statement repeatedly

1. SQL Injection OverviewA SQL injection vulnerability is likely to be introduced in a program that constructs an SQL statement using an unverified external input. Injection attackFor string input, if the string is to be interpreted as some

1. Select the appropriate Oracle OptimizerThere are 3 types of Oracle Optimizer:A. Rule (rule-based) B. Cost (based on costs) c. CHOOSE (selectivity)The default optimizer can be set by various declarations of the Optimizer_mode parameter in the Init.

1.oracle OptimizerThe goal of optimization is divided into 4 categories:Choose (optional)Rule (rules-based)First rows (line one)All rows (all rows)Description: Describe the execution plan for SQLObject owner: Objects SchemaObject Name: Objects