*
* reldesc
* Relation descriptor of the table
+ *
* key
* Partition key information of the table
+ *
* keystate
* Execution state required for expressions in the partition key
+ *
* partdesc
* Partition descriptor of the table
+ *
* tupslot
* A standalone TupleTableSlot initialized with this table's tuple
* descriptor, or NULL if no tuple conversion between the parent is
* required.
+ *
* tupmap
* TupleConversionMap to convert from the parent's rowtype to this table's
* rowtype (when extracting the partition key of a tuple just before
* routing it through this table). A NULL value is stored if no tuple
* conversion is required.
+ *
* indexes
* Array of partdesc->nparts elements. For leaf partitions the index
* corresponds to the partition's ResultRelInfo in the encapsulating