diff options
Diffstat (limited to 'src/include/nodes/plannodes.h')
| -rw-r--r-- | src/include/nodes/plannodes.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index e14257932e6..729e35557d8 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -701,7 +701,11 @@ typedef enum RowMarkType * The tableoid column is only present for an inheritance hierarchy. * When markType == ROW_MARK_COPY, there is instead a single column named * wholerow%u whole-row value of relation - * In all three cases, %u represents the parent rangetable index (prti). + * In all three cases, %u represents the rowmark ID number (rowmarkId). + * This number is unique within a plan tree, except that child relation + * entries copy their parent's rowmarkId. (Assigning unique numbers + * means we needn't renumber rowmarkIds when flattening subqueries, which + * would require finding and renaming the resjunk columns as well.) * Note this means that all tables in an inheritance hierarchy share the * same resjunk column names. However, in an inherited UPDATE/DELETE the * columns could have different physical column numbers in each subplan. @@ -711,6 +715,7 @@ typedef struct PlanRowMark NodeTag type; Index rti; /* range table index of markable relation */ Index prti; /* range table index of parent relation */ + Index rowmarkId; /* unique identifier for resjunk columns */ RowMarkType markType; /* see enum above */ bool noWait; /* NOWAIT option */ bool isParent; /* true if this is a "dummy" parent entry */ |