Oracle

Oracle Archive mode and non-archive mode settingsOracle 's log archiving mode effectively prevents instance and disk failures and is essential in database failure recovery due to the non-archival mode of Oracle 's initial installation mode, So you

Database large segment (CLOB, BLOB) is not suitable for storing more than 1MB of dataTypically, the database provides a large segment type such as Clob,blob,text,long to hold more than 4K of data, however this does not mean that large fields should

The large file tablespace is a new table space type introduced by oracle10g and later versions, primarily for troubleshooting large files. Unlike normal table spaces, a large file table space can only correspond to a single data file or temporary

There is currently a database has a system user Sysuser have all the permissions of the table, another system wants to access a table in my database, I do not want him to control all the tables of my database, all I have a new user, control this

GROUP BY Cube Take a look at the first statement:Select Deptno, Job, sum (SAL) Sal from EMPGroup BY Cube (DEPTNO, Job)Order BY Sal;This output can be seen, there are deptno empty, there is job is empty, there are empty, of course, there are

Oracle Database helps Shanghai Free Trade Zone build a powerful Information System Platform On June 23, October 31, 2014, China Shanghai) Pilot Free Trade Zone (hereinafter referred to as "Shanghai Free Trade Zone") announced the adoption of Oracle

Temporary tables, external tables, and partition tables in OracleTemporary tables, external tables, and partition tables in OracleTemporary table In Oracle, a temporary table is "static". It only needs to be created once like a common data table.

Invalid ale Data Processing and constraintsOther DML statements for data processing: INSERT① Insert into table [(column [, column…])]VALUES (value [, value…]);With this syntax, only one data entry can be inserted into the table at a time. You cannot

Oracle subquery, create, and manage tablesSummarySubquery: Single Row subquery: returns a single rowUse Single Row comparison OperatorsMulti-row subquery: multi-row subquery returns multiple rowsMultiline operators:IN, ANY, ALLIf the query result of

Oracleexp appears & quot; ORA-00302: must describe the SET_NO_OUTLINES component & quot; Solution1. Problem Description Using the oracle exp tool, oracle 11g is installed on my client, and oracle 9i is installed on the server. The following error

Oracle basics-Index 1. What is indexing? A: indexes are used in databases to improve query efficiency. Supplement: too many indexes can greatly reduce the efficiency of DML statements. The indexing principle is to create fields that are frequently

[Oracle] Sequence object usage Sequence: oracle can generate primary keys through sequences.1. Create a sequence Create table Foo (foo_id number (11), foo_value varchar2 (50), constraint FOO_PK primary key (foo_id )) Create sequence DDL Create

Oracle: Other Data Objects (sequences, indexes, synonyms)1. sequence) Sequence: A set of database objects that can be used by multiple users to generate unique values.Unique value automatically providedShared objectIt is mainly used for primary key

Oracle: view) View Concept: Extracts logical data sets from a table.View related concepts:1. A view is a type of continuous table.2. A view is built on an existing table. The tables on which a view is created are called base tables.3. The statement

Oracle Storage Structure1. A data file can belong to only one tablespace at the same time2. segments can be cross-Origin data files. However, the table space cannot be crossed. Partition tables can span tablespaces, and heap tables cannot span

Tomconrefused solution for tomcat7 connection to oracle The server. xml configuration of tomcat is as follows:   The error message is as follows:     java.sql.SQLException: Io exception: Connection refused(DESCRIPTION=(TMP=)(VSNNUM=169870592)

How to install Oracle12c on WIN7 Environment: WIN7 64-bit + Oracle 12c (12.1.0.2.0)Method: Graphical Installation Log on to the system as an administrator:1. Double-click setup.exe under the databasedirectory Remove the "receive Security Updates"

Query OracleCPU usage -- The SQL statements that run a large number of PARSEselect SQL _text, parse_cils, executions from v $ sqlarea order by parse_cils desc; -- select name of the total PARSE of SYS, value from v $ sysstat where name like 'parse

Implicit Oracle ConversionsIt is said that Oracle has implicit conversions of the NUMBER and VARCHAR2 types, which must be avoided in a strict sense, but why should we avoid them? We will verify it from the following experiment.1. Create test tables

Oracle views the properties of a tablespace and modifies the tablespace status.The status attributes of a tablespace mainly include online, offline, read only, and read write, the read-only and read/write statuses are special online situations. By