Oracle

1. Install Oracle client, visit Oracle site to download Oracle Database 11g Release 2 client or (direct download of Oracle 11GR2 Client)2. After downloading the extract, click Setup.exe3. Select Administrator or custom in the installation type4.

Paged Query format:SELECT * FROM(SELECT a.*, ROWNUM RNFrom (SELECT * from table_name) AWHERE ROWNUM )WHERE RN >= 21The most internal query, select * FROM table_name, represents the original query statement without paging. ROWNUM = 21 control the

Oracle "CONNECT by" usesFunction Description:The syntax structure is as follows:[]by[] conditionDescription1. Start with: Tells the system which node to use as the root node to find and construct the result set, which is the highest node in the

The maximum number of Oracle connections is set to 150, and sometimes the program runs off a little. Of course 150 may not be set enough, but usually the headache is to quickly restore the database services, the best way is to restart the database,

1. The isolation level of things: the isolation level of a thing defines the degree of isolation of a transaction.First make clear three concepts: dirty read, non-repeatable read, Phantom read.Dirty reads: When a transaction reads another

Indexing is invalidated when some operations are performed on the partitioned table.The global index is invalidated when there is a truncate/drop/exchange operation partition.The temporary table for Exchange is not indexed, orIndex, no keyword with

MySQL timed script (event), Oracle-like job I have 2 tables: Tb_push_data and Tb_push_data_log now need to back up tb_push_data eligible data to the table at intervals Tb_push_data _log www.2cto.com----------------------------------------------------

Modify the database character set to: ZHS16GBKViewing the server-side character setSQL > select * from V$nls_parametersModify:$sqlplus/nologSql>conn/as sysdba~If the database server is now started, execute SHUTDOWN IMMEDIATE firstTo close the

When creating an index, we often want to be able to estimate the size of the index to assess the impact on an existing engineering environment, and we want to create an index that minimizes the impact of the engineering environment we're running and

Practice: shell script for creating a tablespace in oracle   #! /Bin/bash # ocpyang@126.com # create tablespaceif [$ #-ne 2]; then echo "Usage: $0 TABLESPACE_NAME TABLESPACE_SIZE" exit 1fi # configure oracle env: about oracle envs, username and

The end of IT Ninja Turtles's use of oraclewithas With as syntax-For an aliasWith tmp as (select * from tb_name) -For Multiple aliasesWithTmp as (select * from tb_name ),Tmp2 as (select * from tb_name2 ),Tmp3 as (select * from tb_name3 ),...

Create a tablespace in oracle and test it with the user First, describe the table space as follows: Temporary tablespace: used for grouping operations when sorting large data volumes. Normally, these operations are completed in the memory, but

Oracle Database deletion and import methods 1. Start-run-cmd, and then input sqlplus/as sysdba to connect to the database; 2. delete a user: enter drop user eqm cascade in the dos window; 3. Delete tablespace: enter drop tablespace eqm including

Oracle data file structure Oracle data structures are divided into physical and logical structures.   Physical Structure: data block of the Operating System-> data file datafiles Logical Structure: Minimum database block --> extent -->

REGEXP_SUBSTR function (convert) and oraclesubstr function in Oracle REGEXP_SUBSTR function in Oracle Instructions for using the REGEXP_SUBSTR function in Oracle: The questions are as follows:In oracle, a statement is used to split '17, 20,23' into

Oracle Performance Analysis 7: Creating an index When creating an index, we often want to estimate the index size to evaluate the impact on the existing engineering environment. We also hope that the index creation process will minimize the impact

Oracle online extended partitions In the Partition Table operation, when a partition already has the largest partition, how can we expand the partition again? The simple method is to delete the maximum partition first, then add the required

Difference between Oraclealterindexdisable and unusable Alter index index_name disable, enable for function indexes. SQL> create table test as select * from all_objects;SQL> create index ind_t_object_id on test (object_id) nologging; SQL> exec

ORACLE10G installed on Centos6.4 Note: This installation is only limited to the installation of ORACLE10G on Centos6. for installation of other versions of the operating system, please refer to the official oracle documentation for installation. 1.

Oracle index quality introduction and analysis script sharing, oracle index script sharing The index quality has a direct impact on the overall performance of the database. Good and high-quality indexes increase the database performance by an order