Specifies partitioning of table data, through a
PARTITION BY clause in the table definition:
PARTITION BY partition‑expression [ GROUP BY group‑expression ]
For each table row, resolves to a partition key that is derived from one or more table columns.
Caution: Avoid partitioning tables on LONG VARBINARY and LONG VARCHAR columns. Doing so can adversely impact performance.
For each table row, resolves to a partition group key that is derived from the partition key. Vertica uses group keys to merge partitions into separate partition groups.
...PARTITION BY (i+j) GROUP BY (
Partitioning 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 expression; otherwise, Vertica cannot resolve the expression.
- The 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:
- The expression cannot include queries.
GROUP BY expressions do not support modulo (%) operations.
Partitioning Tables in the Administrator's Guide