Purpose
The DBA_SEGMENTS view displays the storage allocated for all segments in the database.
Applicability
This topic applies only to OceanBase Database Enterprise Edition. OceanBase Database Community Edition provides only the MySQL mode.
Related views
USER_SEGMENTS
Columns
| Column | Type | Nullable? | Description |
|---|---|---|---|
| OWNER | VARCHAR2(128) | NO | The owner of the segment. |
| SEGMENT_NAME | VARCHAR2(128) | NO | The name of the segment if any. |
| PARTITION_NAME | VARCHAR2(128) | NO | The name of the partition. For non-partitioned objects, the value of this column is NULL. |
| SEGMENT_TYPE | VARCHAR2(18) | NO | The type of the segment. |
| SEGMENT_SUBTYPE | VARCHAR2(10) | NO | The sub type of the LOB segment of a large field. At present, this column is not supported and is NULL by default. |
| TABLESPACE_NAME | VARCHAR2(30) | NO | The name of the tablespace containing the segment. At present, this column is not supported and is NULL by default. |
| HEADER_FILE | NUMBER | NO | The ID of the file containing the segment header. At present, this column is not supported and is NULL by default. |
| HEADER_BLOCK | NUMBER | NO | The ID of the block containing the segment header. At present, this column is not supported and is NULL by default. |
| BYTES | NUMBER(38) | NO | The size of the segment in bytes. |
| BLOCKS | NUMBER(38) | NO | The size of the segment block. |
| EXTENTS | NUMBER | NO | The number of extents allocated to the segment. At present, this column is not supported and is NULL by default. |
| INITIAL_EXTENT | NUMBER | NO | The size in bytes requested for the initial extent of the segment at creation time. At present, this column is not supported and is NULL by default. |
| NEXT_EXTENT | NUMBER | NO | The size in bytes of the next extent to be allocated to the segment. At present, this column is not supported and is NULL by default. |
| MIN_EXTENTS | NUMBER | NO | The minimum number of extents allowed in the segment. At present, this column is not supported and is NULL by default. |
| MAX_EXTENTS | NUMBER | NO | The maximum number of extents allowed in the segment. At present, this column is not supported and is NULL by default. |
| MAX_SIZE | NUMBER | NO | The maximum number of blocks allowed for the segment. At present, this column is not supported and is NULL by default. |
| RETENTION | VARCHAR2(7) | NO | Reserved field in the SecureFile. At present, this column is not supported and is NULL by default. |
| MINRETENTION | NUMBER | NO | The minimum retention duration of SecureFile. At present, this column is not supported and is NULL by default. |
| PCT_INCREASE | NUMBER | NO | The percentage by which the size of the next block to be allocated increases. At present, this column is not supported and is NULL by default. |
| FREELISTS | NUMBER | NO | The number of process freelists allocated to this segment. At present, this column is not supported and is NULL by default. |
| FREELIST_GROUPS | NUMBER | NO | The number of freelist groups allocated to this segment. At present, this column is not supported and is NULL by default. |
| RELATIVE_FNO | NUMBER | NO | The relative file number of the segment header. At present, this column is not supported and is NULL by default. |
| BUFFER_POOL | VARCHAR2(7) | NO | The buffer pool for segment blocks. |
| FLASH_CACHE | VARCHAR2(7) | NO | The database smart flash cache hint for segment blocks. |
| CELL_FLASH_CACHE | VARCHAR2(7) | NO | The cell flash cache hint for segment blocks. |