DBA_TAB_COLUMNS
Description des colonnes des tables.
| Nom de la colonne | Description |
| OWNER | Owner of the table, view, or cluster |
| TABLE_NAME | Table, view, or cluster name |
| COLUMN_NAME | Column name |
| DATA_TYPE | Type colonne of the column |
| DATA_LENGTH | Length of the column in bytes |
| DATA_PRECISION |
Decimal precision for NUMBER Type colonne; binary precision for FLOAT Type colonne; NULL for all other Type colonnes
|
| DATA_SCALE | Digits to right of decimal point in a number |
| NULLABLE | Does column allow NULL values? |
| COLUMN_ID | Sequence number of the column as created |
| DEFAULT_LENGTH | Length of default value for the column |
| NUM_DISTINCT | The number of distinct values for the column |
| LOW_VALUE |
The smallest value for the column, expressed in hexadecimal notation for the internal representation of the first 32 bytes of the value
|
| HIGH_VALUE |
The highest value for the column, expressed in hexadecimal notation for the internal representation of the first 32 bytes of the value
|
| DENSITY |
The density of the column (a measure of how distinct the values are). The densit is calculated as the sum of occurrences2/elements_sampled2 for each distinct value in the column.
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