A table space can only belong to a database each database with a control file (suggest 3, put on different disks) Each database has a table space (System table space) to establish the purpose of the SYSTEM table space is to try to Put the same table as the destination to improve the efficiency of use, only two online log groups should only be stored, each group of online log files can only belong to a tablespace one data file. In a table space, you can no longer be removed from this table space, and you can no longer join in other tablespaces to create new tablespaces, need to create new data file data files are formatted by Oracle to Oracle block, Oracle9i In previous versions, the size of the Oracle block is set when it is created in the first time, and it cannot be changed in the future, to change, only a segment segment that can only be reconstructed, but can belong to multiple data files A zone extent can only belong to a data file, ie intervals cannot span data files PCTFREE and PCTUSED summary cannot be greater than or equal to 100 individual transactions cannot span multiple returns to the index table without ROWID values with different sizes. Without any benefit commit, the data is not necessarily written (data files), even if it is not submitted, it will be written to the redo log even if it is not submitted. ORACLE 8.0.4, the default database established in the initial installation, the instance is the maximum length of one block (2K, 4K, 8K, 16K) per database (by block size) 2K block 20000 file 4K block 40000 file 8K block or more 65536 file Oracle Server can start multiple databases at the same time on a set of operating systems (UNIX can, NT can not) set an Oracle database system There are multiple Oracle databases and their corresponding examples each Oracle database has a database instance (except for OPS), so a set of operating systems can have multiple Oracle database instances.
