Data Partitioning
Tables can be merged into one virtual Merge Table to provide data partitioning.
Optionally the merge table can have a table partitioning scheme allowing data to be partitioned automatically
by column or expression and on distinct values or value ranges upon insert.
The partitioning schemes are stored in below system tables:
sys.table_partitions
| name | type | references | description |
|---|
| "id" | INTEGER | | The unique internal identifier for the table partition. |
| "table_id" | INTEGER | sys.tables.id | The merge table id this partition belongs to. |
| "column_id" | INTEGER | sys.columns.id | The merge table's column id by which the partitioning data is selected OR null when an expression is used. |
| "expression" | VARCHAR | | The merge table's expression by which the partitioning data is selected OR null when a column is used. |
| "type" | INTEGER | | The partitioning type: 5=By Column Range, 6=By Expression Range, 9=By Column Value, 10=By Expression Value. |
sys.range_partitions
| name | type | references | description |
|---|
| "table_id" | INTEGER | sys.tables.id | The partition table id this partition belongs to. |
| "partition_id" | INTEGER | sys.table_partitions.id | The merge table's partition id this range partition belongs to. |
| "minimum" | VARCHAR | | The minimum value of the range. Can be null when WITH NULL VALUES is specified. |
| "maximum" | VARCHAR | | The maximum value of the range. Can be null when WITH NULL VALUES is specified. |
| "with_nulls" | BOOLEAN | | Whether this range also include the NULLs of the Column/Expression. |
sys.value_partitions
| name | type | references | description |
|---|
| "table_id" | INTEGER | sys.tables.id | The partition table id this partition belongs to. |
| "partition_id" | INTEGER | sys.table_partitions.id | The merge table's partition id this value partition belongs to. |
| "value" | VARCHAR | | The partitioning value. Can be null when WITH NULL VALUES is specified. |