Oracle 数据库的限制(9iR2)

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Physical Database Limits
<!--/TOC=h1--> ItemType of LimitLimit Value Database Block Size
  Minimum
  2048 bytes; must be a multiple of operating system physical block size
Maximum
  Operating system dependent; never more than 32 KB
Database Blocks
  Minimum in initial extent of a segment.
  2 blocks
Maximum per datafile
  Platform dependent; typically 222-1 blocks
Controlfiles
  Number of control files
  1 minimum; 2 or more (on separate devices) strongly recommended
Size of a control file
  Dependent on operating system and database creation options; maximum of 20,000 x (database block size)
Database files
  Maximum per tablespace
  Operating system dependent; usually 1022
Maximum per database
  65533
May be less on some operating systems
Limited also by size of database blocks and by the DB_FILES initialization parameter for a particular instance
Database extents
  Maximum
  4 GB, regardless of the maximum file size allowed by the operating system
Database file size
  Maximum
  Operating system dependent. Limited by maximum operating system file size; typically 222 or 4M blocks
MAXEXTENTS
  Default value
  Derived from tablespace default storage or DB_BLOCK_SIZE initialization parameter
Maximum
  Unlimited
Redo Log Files
  Maximum number of logfiles
  Limited by value of MAXLOGFILES parameter in the CREATE DATABASE statement
Control file can be resized to allow more entries; ultimately an operating system limit
Maximum number of logfiles per group
  Unlimited
Redo Log File Size
  Minimum size
  50 KB
Maximum size
  Operating system limit; typically 2 GB
Tablespaces
  Maximum number per database
  64 K
Number of tablespaces cannot exceed the number of database files, as each tablespace must include at least one file
Process and Runtime Limits
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ItemTypeLimit Instances per database
  Maximum number of cluster database instances per database
  Operating system-dependent
Locks
  Row-level
  Unlimited
Distributed Lock Manager
  Operating system dependent
SGA size
  Maximum value
  Operating system-dependent; typically 2 to 4 GB for 32-bit operating systems, and > 4 GB for 64-bit operating systems
Advanced Queuing Processes
  Maximum per instance
  10
Job Queue Processes
  Maximum per instance
  1000
I/O Slave Processes
  Maximum per background process (DBWR, LGWR, etc.)
  15
Maximum per Backup session
  15
Sessions
  Maximum per instance
  32 KB; limited by the PROCESSES and SESSIONS initialization parameters
Global Cache Service Processes
  Maximum per instance
  10
Shared Servers
  Maximum per instance
  Unlimited within constraints set by the PROCESSES and SESSIONS initialization parameters, for instance
Dispatchers
  Maximum per instance
  Unlimited within constraints set by PROCESSES and SESSIONS initialization parameters, for instance
Parallel Execution Slaves
  Maximum per instance
  Unlimited within constraints set by PROCESSES and SESSIONS initialization parameters, for instance
Backup Sessions
  Maximum per instance
  Unlimited within constraints set by PROCESSES and SESSIONS initialization parameters, for instance