Partition Clause

A table definition specifies partitioning through a PARTITION BY clause:

PARTITION BY expression

where expression resolves to a value derived from one or more table columns.

Requirements and Restrictions

PARTITION BY expressions can specify leaf expressions, functions, and operators. The following requirements and restrictions apply:

• All table projections must include all columns referenced in the PARTITION BY expression; otherwise, Vertica cannot resolve the expression.
• A partition clause expression can reference multiple columns, but it must resolve to a single non-null value for each row.
• All leaf expressions must be constants or table columns.
• All other expressions must be functions and operators. The following restrictions apply to functions:
  • They must be immutable—that is, they return the same value regardless of time and locale and other session- or environment-specific conditions.
  • They cannot be aggregate functions.
  • They cannot be Vertica meta-functions.
• A partition clause expression cannot include queries.

See Also

Using Table Partitions in the Administrator's Guide.