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Oracle® Database Reference 10g Release 2 (10.2) Part Number B14237-02 |
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# 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
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 per dictionary managed tablespace | `4` GB * physical block size (with K/M modifier); `4` GB (without K/M modifier)
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
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 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 32K blocks and 32TB for a tablespace with 8K 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.