Contains one row for each column that is defined for a table or
view. All of the catalog views have entries in the
SYSCAT.COLUMNS table.
Table 41. SYSCAT.COLUMNS Catalog View
| Column Name | Data Type | Nullable | Description | ||
|---|---|---|---|---|---|
| TABSCHEMA | CHAR(8) |
| Qualified name of the table or view that contains the column. | ||
| TABNAME | VARCHAR(18) |
| |||
| COLNAME | VARCHAR(18) |
| Column name. | ||
| COLNO | SMALLINT |
| Numerical place of column in table or view, beginning at zero. | ||
| TYPESCHEMA | CHAR(8) |
| Contains the qualified name of the type, if the data type of the column is distinct. Otherwise TYPESCHEMA contains the value SYSIBM and TYPENAME contains the data type of the column (in long form, for example, CHARACTER). If FLOAT or FLOAT(n) with n greater than 24 is specified, TYPENAME is renamed to DOUBLE. If FLOAT(n) with n less than 25 is specified, TYPENAME is renamed to REAL. Also, NUMERIC is renamed to DECIMAL. | ||
| TYPENAME | VARCHAR(18) |
| |||
| LENGTH | INTEGER |
| Maximum length of data. 0 for distinct types. The LENGTH column indicates precision for DECIMAL fields. | ||
| SCALE | SMALLINT |
| Scale for DECIMAL fields; 0 if not DECIMAL. | ||
| DEFAULT | VARCHAR(254) | Yes | Default value for the column of a table expressed as a constant, special
register, or cast-function appropriate for the data type of the column.
May also be the keyword NULL.
Values may be converted from what was specified as a default value. For example, date and time constants are presented in ISO format and cast-function names are qualified with schema name and the identifiers are delimited (see Note 3). Null value if a DEFAULT clause was not specified or the column is a view column. | ||
| NULLS | CHAR(1) |
|
Y=Column is nullable. N=Column is not nullable. The value can be N for a view column that is derived from an expression or function. Nevertheless, such a column allows nulls when the statement using the view is processed with warnings for arithmetic errors. See Note 1.
| ||
| CODEPAGE | SMALLINT |
| Code page of the column. For character-string columns not defined with the FOR BIT DATA attribute, the value is the database code page. For graphic-string columns, the value is the DBCS code page implied by the (composite) database code page. Otherwise, the value is 0. | ||
| LOGGED | CHAR(1) |
| Applies only to columns whose type is LOB or distinct based on LOB (blank
otherwise).
Y=Column is logged. N=Column is not logged. | ||
| COMPACT | CHAR(1) |
| Applies only to columns whose type is LOB or distinct based on LOB (blank
otherwise).
Y=Column is compacted in storage. N=Column is not compacted. | ||
| COLCARD | INTEGER |
| Number of distinct values in the column; -1 if statistics are not gathered. | ||
| HIGH2KEY | VARCHAR(33) |
| Second highest value of the column. This field is empty if statistics are not gathered. See Note 2. | ||
| LOW2KEY | VARCHAR(33) |
| Second lowest value of the column. Empty if statistics not gathered. See Note 2. | ||
| AVGCOLLEN | INTEGER |
| Average column length. -1 if a long field or LOB, or statistics have not been collected. | ||
| KEYSEQ | SMALLINT | Yes | The column's numerical position within the table's primary key. This field is null or 0 if the column is not part of the primary key. | ||
| PARTKEYSEQ | SMALLINT | Yes | The column's numerical position within the table's partitioning key. This field is null or 0 if the column is not part of the partitioning key. | ||
| NQUANTILES | SMALLINT |
| Number of quantile values recorded in SYSCAT.SYSCOLDIST for this column; -1 if no statistics. | ||
| NMOSTFREQ | SMALLINT |
| Number of most-frequent values recorded in SYSCAT.COLDIST for this column; -1 if statistics not gathered. | ||
| REMARKS | VARCHAR(254) | Yes | User-supplied comment. | ||
| |||||