11g new feature _ visible and invisible index, and 11g new feature index visible When you want to evaluate the impact of an index on your SQL query statement, when your database is 11 GB, you can quickly set the index to VISIBLE or INVISIBLE. In
SQL server calculates the value of a field in the database, removes duplicate data, and SQL server Sometimes, some duplicate data exists in the database, but we want to calculate the value of a field, and we need to remove the duplicate data ,: In
In Atitit. Hibernate, Criteria uses summary and join queries and queries o9o and hibernatecriteria by sub-objects. In Atitit. Hibernate, Criteria uses summary and association query and queries o9o by sub-Object 1. Criteria, Criterion, 13. Criteria
Hibernate query method Use HQL to query data Hibernate provides the following query methods: 1. OID Query Method You can use the get () and load () methods provided by the session to load the specified OID object. You can only query by Object id. 2.
Clob is saved as a local xml file. After modification, it is uploaded. clobxml I wrote a small program with my friends over the past two days. The functions are as follows: First, save the database clob as a local xml file, modify the xml file, and
Create a table synchronization trigger for each site for data synchronization and a data synchronization trigger As mentioned in the previous blog, when data synchronization is performed, you need to create a trigger for each operation table on each
New MySQL users and Database Access authorization, new mysql # Mysql-u root-p # Allow local IP addresses to access localhost, 127.0.0.1 # insert into mysql. user (Host, User, Password) values ('localhost', 'zhouz', password ('000000'); # allow
Why Does Oracle Rac opatch auto fail to hit Rac database home?First explain the environment: OS: AIX 7.1Oracle version: Oracle Rac 126.96.36.199 before the release of the 188.8.131.52.9 Patch Set, Rac is not officially used, so simply hit the latest 184.108.40.206.
Installing 220.127.116.11 or 18.104.22.168 db sofrware on rhel6 reports a lack of "elfutils-libelf-devel-0.97" And "pdksh-5.2.14 ", Installing 22.214.171.124 Or 126.96.36.199 (32-bit (x86) or 64-bit (x86-64) On RHEL6 Reports That Packages "elfutils-libelf-devel-0.97" And
Oracle to_date error caused by different language Environments I wrote a stored procedure and used a function in it. The function contains a to_date (dateFrom, 'yyyy/mm/dd'). After running the function, I found that the data was inserted incorrectly,
When the mysql PRIMARY key is set to auto_increment, the PRIMARY key repeat Duplicate entry 'xxx' for key 'Primary ', duplicateentry occurs during the concurrent performance test. When the mysql PRIMARY key is set to auto_increment, the PRIMARY key
ORA-27090 fault case and ora-27090 fault case The recent alert Log encountered an error message for the ORA-27090 with the error prompt Unable to reserve kernel resources for asynchronous disk I/O. According to this prompt, It is a kernel parameter
Relationship Pattern Design Theory and Pattern Design Theory Normalization: A low-level paradigm can be transformed into a relational model of several advanced paradigms through Mode Decomposition, that is, normalization. Paradigm: Currently,
MySQL character encoding problem, Incorrect string value, mysqlincorrectAn error is reported when inserting Chinese Characters in MySQL. For details, refer to the analysis below.Incorrect string value: '\ xD0 \ xC2 \ xC8A \ xbew' for column 'ctnr'
Oracle listener lsnrctl, listenerlsnrctl Lsnrctl (Listener Control) is an SQL * Net tool used to Control the listener database. This tool provides commands to Control the start and stop of listener and view the status of listener, changes the
Common orcle statements and orcle statements -- 1. create temporary tablespace AUTOMONITORV5_temptempfile 'd: \ ORACLE \ KARL \ ORADATA \ ORCL \ automonitorv5_temp.dbf' size 50 m autoextend on next 50 m maxsize 10240 m extent management local; -- 2.
Add and read comments and ORACLE comments to tables and columns in oracle Add and read comments to tables and columns in ORACLE1. Add a comment to the table: SQL> comment on table name is 'table comment "; 2. Add a comment to the column: SQL>
Use Oracle DBLink to access objects between databases. Oracle comes with the DBLink function. It is used to logically think of multiple oracle databases as one database, that is, one database can operate on objects in another database, for example,
Database Design-semi-structured storage and database structured storage Business scenario: the user fills in some documents, reports them, and approves them. There are several fields in the document that need statistics, and the business is not
Paging process for pl/SQL writing, paging for plsql writing-- Develop a package-- Create a package. In this package, the test_cursor type is defined as a cursor. As follows:SQL code Create or replace package testpackage TYPE test_cursor is ref