Oracle

In Oracle SQL, union is also a common statement. Note that the Union statement of Oracle filters out duplicate data by default. That is to say, Oracle union has a distinct Statement by default. So how can we not need this attribute? We need to add

Oracle series: Image Storage I. What are basic operations for large objects?See my blog: Oracle series: Lob big object processingHttp://blog.csdn.net/qfs_v/archive/2008/05/21/2464599.aspx 2. Image Storage or binary file storage 1. Insert common data

Document directory Oracle series: Record and PL/SQL tables Oracle series: Record and PL/SQL tables 1. What are record and PL/SQL tables? Record: a temporary record object type consisting of a single row and multiple columns of scalar type.

Oracle series: connecting to Oracle servers When a user connects to a database server, it becomes the database client. The two can exist on the same machine. 1. Configure the Oracle server1. Configure the listener① The listener listens to and

Document directory Failed to call LoadLibraryEx, on ISAPI filter "C:/Windows/Microsoft. NET/Framework/v4.0.30319/aspnet_filter.dll" BadImageFormatException is thrown when you try to load the Oracle client library. This problem occurs when the 32

Tree query and connect by in OracleUsing connect by and start with to create a report similar to a tree is not difficult, as long as you follow the following basic principles:When using connect by, the order of each clause should

Oracle ref cursors Version 10.2: Stronugly Typed Note: A ref cursor that specifies a specific return type. Package Header Create or replace

The table contains 5 million records, which are not indexed: Set timing onSet autotrace traceonly SQL> select count (*), to_char (time, 'hh24') from userloginlog2 Where trunc (time) = trunc (sysdate)-13 group by to_char (time, 'hh24 ')4 order by

Oracle 9i contains the XDB feature by default when creating a database. Once the database and Listener are started, Oracle XDB starts the http service. It is easy to disable the XDB service of oracle. just remove the initialization parameters of the

Test environment: OS: XPIn ORACLE 10.1SQLSERVER2000HOSTNAME: home-30b98e1e20Both use the default TCP/IP Port 1. Install the transparent gateway OptionUse Oracle Universal Instraller to choose custom installation on the installed ORACLE_HOME, and

Convert to long: Select (FIRSTARRIVALTIME-to_date ('1970-01-01 00:00:00 ', 'yyyy-mm-dd hh24: mi: ss') * 24*60*60 from ats_plat_time_info; Select (sysdate-to_date ('1970-01-01 00:00:00 ', 'yyyy-mm-dd hh24: mi: ss') * 24*60*60 from dual; Convert

[From: http://blog.csdn.net/wzy0623/archive/2009/09/27/4599615.aspx] What operations does oracle perform when we submit an SQL statement?Oracle assigns a server process to each user process: service process (dedicated server and shared server should

Http://blog.csdn.net/rookie_one/archive/2006/11/30/1421781.aspx   When I got off work yesterday, I thought my computer name was too ugly and I changed it to something else. (It was too hasty to install the system. The installer added a lot of messy

Http://www.javaeye.com/topic/193649   1./* + ALL_ROWS */It indicates that the overhead-based optimization method is selected for the statement block, and the optimal throughput is obtained to minimize the resource consumption.For example:SELECT/* +

(1) select the most efficient table name sequence (only valid in the rule-based Optimizer ): The ORACLE parser processes the table names in the FROM clause in the order FROM right to left. The table written in the FROM clause (basic table driving

I. Question proposal At the early stage of application system development, due to the relatively small amount of data in the development database, the performance of SQL statement writing is not good for querying SQL statements and writing complex

Oracle employee Points Ranking   Create View   Select t. operate_date,T. operate_user,T. operate_dept,T. add_score +T. modify_score +T. over_score +T. delete_score +T. up_score +T. down_score +T. use_score +T. opinion_score +T. advice_score +T.

At the beginning of the function, I was asked to write an oracle stored procedure and send mail. I have done this before, and directly copy the previous code to achieve it easily. To make a record, I copied the code. The code is easy to understand

There are 16.77 million data records in a table, and 5.71 million data records are different. When not all fields have the same content, for example, 100 people with the same name and surname have different salaries, and other fields have the same

Database stress testing 1. Use orabm to test the database CPUOrabm tests the system performance by running a specified number of transactions at a specified concurrency. It mainly tests the CPU performance and memory of the database server.Orabm is