Oracle

 Invisible ColumnsThis column is not visible using SELECT * FROM, DESC, etc. DROP TABLEtab1 PURGE;CREATE TABLEtab1 (ID Number, DescriptionVARCHAR2( -) INVISIBLE);DESCTab1; NameNull? Type----------------------------------------- -------- ---------

Take advantage of the system global area SGA:The SGA is the heart of the Oracle database. The user's process sends transactions to this memory area and reads the hit data here as a cache for acceleration purposes. The correct SGA size is critical to

Oracle implements MySQL-like find_in_set sorting, function decode:by default7#zbphp.comRefer to Cdsn's post: http://topic.csdn.net/t/20060124/08/4532718.htmlQuestions:-----------------------------------------------------------------------------------

when you add a record, HWM slowly moves up, but when you delete a record, HWM does not move down. Therefore, deleting large amounts of data with the delete from command can cause performance problems caused by HWM. The most straightforward way to

Oracle gives the feeling is very backward, the use is very inconvenient, Toad this software is stupid and dull, PL/SQL is, the 90 's interface style, speed still stuck to death. and Oracle does not support limit. by default7#zbphp.comUpdate tb_news

Byte[] Xx=encoding.default.getbytes ("12121232");Insert DatabaseString sqlstr = "Update Sys_tab t set T.big_logo =:big_logo,t.small_logo=:small_logo where Id=:id";Oracleparameter[] ParameterValue = {New OracleParameter (": Big_logo", Oracletype.blob)

/** * Value by page number (starting from Current_page page, page_size per page) * @param key * @param params * @param current_page * @param page_size * @retur n */public pagination getpaginationbypage (String key, Object params,int

The Oracle garbled problem is usually caused by inconsistencies in the Oracle character set settings and operating system character set settings, which have to mention two operating system environment variables, LANG and Nls_langLang is a set of

Stored procedures within Oracle are returned by a cursor to the result setDataTable dt =NewDataTable (); Oracleparameter[] Paras=Neworacleparameter[5]; paras[0] =NewOracleParameter ("P_starttime", Oracletype.char); paras[0]. Value =StartTime; paras[1

Select Sys_guid () from dual;-->78ae331adb2b4ce7ab598b1317b39d58But the function has the following problem: 1 . The return type is raw 2 . No- (dash) delimiter 3 . Capitalization of letters returnedTo make the resulting UUID conform to the RFC

The SRVCTL command can control Instance,listener and services in the RAC database. Typically SRVCTL is executed under Oracle user. Let's introduce the SRVCTL command. 1, through the SRVCTL command to Start/stop/check all instances: $ srvctl

1. Parse tables and indexes (analyze does not rebuild the index )Analyze table TableName COMPUTE statisticsEquivalent to analyze table TableName compute statistics for table for all indexes for all columnsStatistics for table exist in views:

Install Oracle 10g (redhat 4) and oracleredhat in Linux -- Note: This article only installs Oracle and does not create a database.1. Install a readhat 4 System in the Virtual Machine. 2. Configure the IP address. The configured IP address is as

Fix the index with status unusable and statusunusable Log On with the DBA permission and execute the following script. Declare-- Cursor pointing to the index of all UNUSABLE statesCursor c isSelect index_name, ownerFrom dba_indexesWhere status =

Oracle download and installation, oracle download and InstallationOracle download and Installation1. Official Address: Beijing. Win 32-bit operating system:

Start Oracle11g Service When running oracle, It is very resource-consuming and affects the speed of the machine. Therefore, I usually stop its services when I don't need oracle, but what services do we need to start and what do we do? The following

Oracle group summary statistics function grouping Two days ago, a colleague asked an oracle database to use grouping to complete a statistical report function. This function is pretty cool. The development grouping report can be done simply with an

ORA-24247: Network Access denied access control list (ACL)Zookeeper ORA-24247: Network Access denied access control list (ACL)Note: The command must be used under the system user.You must first use DBMS_NETWORK_ACL_ADMIN.CREATE_ACL to create an

Clear the high watermark line of an Oracle tableWhen a new record is added, HWM moves up slowly, but HWM does not move down after the record is deleted. Therefore, when you use the delete from command to delete a large amount of data, the HWM may

An error occurred while inserting a datagram string into the CLOB attribute of the Oracle database. Insert an article (1000 ~ 2000. Stream processing is not used on the Internet. This is like a Bug. You only need to extend the inserted data to