PROJECTION_COLUMNS
Provides information about projection columns, such as encoding type, sort order, type of statistics, and the time at which columns statistics were last updated.
Column Name | Data Type | Description |
---|---|---|
PROJECTION_ID
|
INTEGER
|
Catalog-assigned numeric value that uniquely identifies the projection. |
PROJECTION_NAME
|
VARCHAR
|
The projection name for which information is listed. |
PROJECTION_COLUMN_NAME
|
VARCHAR
|
The projection column name. |
COLUMN_POSITION
|
INTEGER
|
The ordinal position of a projection's column used in the |
SORT_POSITION
|
INTEGER
|
The projection's column sort specification, as specified in |
COLUMN_ID
|
INTEGER
|
A unique numeric object ID (OID) that identifies the associated projection column object and is assigned by the Vertica catalog. This field is helpful as a key to other system tables. |
DATA_TYPE
|
VARCHAR
|
Matches the corresponding table column data type (see |
ENCODING_TYPE
|
VARCHAR
|
The encoding type defined on the projection column. |
ACCESS_RANK
|
INTEGER
|
The access rank of the projection column. See the |
GROUP_ID
|
INTEGER
|
A unique numeric ID (OID) that identifies the group and is assigned by the Vertica catalog. |
TABLE_SCHEMA
|
VARCHAR
|
The name of the schema in which the projection is stored. |
TABLE_ID
|
INTEGER
|
Catalog-assigned numeric value that uniquely identifies the table. |
TABLE_NAME
|
VARCHAR
|
The table name that contains the projection. |
TABLE_COLUMN_ID
|
VARCHAR
|
Catalog-assigned VARCHAR value that uniquely identifies a table column. |
TABLE_COLUMN_NAME
|
VARCHAR
|
The projection's corresponding table column name. |
STATISTICS_TYPE
|
VARCHAR
|
The type of statistics the column contains:
|
STATISTICS_UPDATED_TIMESTAMP
|
|
The time at which the columns statistics were last updated by |
IS_EXPRESSION
|
BOOLEAN
|
Indicates whether this projection column is calculated with an expression. For aggregate columns, |
IS_AGGREGATE
|
BOOLEAN
|
Indicates whether the column is an aggregated column in a live aggregate projection. |
PARTITION_BY_POSITION
|
INTEGER
|
Position of that column in the PARTITION BY and GROUP BY clauses, if applicable. |
ORDER_BY_POSITION
|
INTEGER
|
Set only for Top-K projections, specifies the column's position in the ORDER BY clause, as defined in the projection definition's window partition clause. If the column is omitted from the ORDER BY clause, ORDER_BY_POSITION output is NULL. |
ORDER_BY_TYPE
|
INTEGER
|
Type of sort order:
|
COLUMN_EXPRESSION
|
VARCHAR
|
Expression that calculates the column value. |
Examples
See Statistics Data in PROJECTION_COLUMNS