Author: Huang Lin graduated from college in 1998. After participating, the hardware design and corresponding software development of multiplexed single-chip microcontrollers are advanced. The language used is 8031 and 8051 and 8086, and now mainly engaged in the development of the database, including Informix, SQLServer, and Oracle, the language Powerbuild, Java, VS.NET, design tools include PowerDesign, Rational Rose, ER-WIN, and the project developed is basically a provincial and ministerial project. In three-layer development, it is more familiar to middleware WebLogic and Silverstream. In addition to the above work, it is more familiar with software capability maturity model CMM3 in software standardization management. -------------------------------------------------- --------------------------- Oracle database as a large relational database, there are many other relational databases Personality, which makes a simple description, including the knowledge that we may use in daily operations and maintenance, I hope to help everyone, basic knowledge 1, table space for database is unique, and requires each There is a table in a database. Table space can be divided into system table space and non-system table space, rollback segment table space; can also be divided into user tablespace and non-user table space, they are only different, in fact, in fact, temporary table space: temporary table space Does not include real data, the method of recovery is to delete temporary tablespaces and rebuild .. System Table Space: If the backup is not available, you can only use the method of rebuilding the database. The size of the table space can make setting table space as needed and the device can be easily understood as space to store information. We generally create a database system in the following order: Create a table space - "Modify the table space ---" Create a rollback segment - "Create User and Authorization -" Create User Table - "Create Table Index, users can establish their own database system as long as they press this order, as for the created database has the best Performance, I will do special discussions in future articles. The establishment of the table space can be very convenient to establish a graphical user interface. I believe everyone will, here I don't conduct a detailed introduction, I will build a table space, modify the table space, build a roll, create users, and authorization. Create a table, after creating the indexed SQL attached, please refer to: 2, the control file is essential in each database, in order to improve the performance of the database, it is recommended to build multiple control files, ask the requirements on different disks. The Oracle database consists of three files, control files, and online log files. Due to changes in disk space, or based on the adjustment of database disk I / O performance, the database administrator may consider moving database files. The following is a UNIX platform as an example, discussing the mobile method of three database files, cannot be overlooked, please note that the log file is very important log files to recover the database can be divided into online logs and offline logs, online logs can record each Oracle. All modifications made in the database. A online log consists of multiple online log files, and each running Oracle database instance has an online log, which works with the Oracle background process LGWR, and records all modifications made by this instance. The offline log is optional • When Oracle is filled with online log files, it will be archived.
Second, create a table space, rollback segments, user, table syntax 1, create table space (this is the first step in the database, the table space is better than the container, including the various things of the database in it ) CREATE tABLESPACE test DATAFILE '/ dev / test_name1' SIZE 1000M, '/ dev / test_name2' SIZE 1000M, '/ dev / test_name3' SIZE 1000MDEFAULT STORAGE (INITIAL 64K NEXT 64K MAXEXTENTS UNLIMITED PCTINCREASE 50); NOTE: there is no tablespaces Extension is limited.
