Physical Database Limits
Item | Type of Limit | Limit Value |
---|---|---|
Database Block Size | Minimum | 2048 bytes; must be a multiple of operating system physical block size |
Database Block Size | Maximum | Operating system dependent; never more than 32 KB |
Database Blocks | Minimum in initial extent of a segment | 2 blocks |
Database 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 |
Controlfiles | Size of a control file | Dependent on operating system and database creation options; maximum of20,000 x (database block size) |
Database files | Maximum per tablespace | Operating system dependent; usually 1022 |
Database files | 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 per dictionary managed tablespace | 4 GB * physical block size (with K/M modifier); 4 GB (without K/M modifier) |
Database extents | Maximum per locally managed (uniform) tablespace | 2 GB * physical block size (with K/M modifier); 2 GB (without K/M modifier) |
Database file size | Maximum | Operating system dependent. Limited by maximum operating system file size; typically 222 or 4 MB blocks |
MAXEXTENTS | Default value | Derived from tablespace default storage or DB_BLOCK_SIZE initialization parameter |
MAXEXTENTS | 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
|
Redo Log Files | Maximum number of logfiles per group | Unlimited |
Redo Log File Size | Minimum size | 4 MB |
Redo Log File Size | 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 because each tablespace must include at least one file
|
Bigfile Tablespaces | Number of blocks | A bigfile tablespace contains only one datafile or tempfile, which can contain up to approximately 4 billion ( 232 ) blocks. The maximum size of the single datafile or tempfile is 128 terabytes (TB) for a tablespace with 32 K blocks and 32 TB for a tablespace with 8 K blocks. |
Smallfile (traditional) Tablespaces | Number of blocks | A smallfile tablespace is a traditional Oracle tablespace, which can contain 1022 datafiles or tempfiles, each of which can contain up to approximately 4 million (222) blocks. |
External Tables file | Maximum size | Dependent on the operating system.
An external table can be composed of multiple files.
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