diff options
Diffstat (limited to 'src/include/nodes/relation.h')
| -rw-r--r-- | src/include/nodes/relation.h | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h index 6d7b5948cd9..a9219e0be95 100644 --- a/src/include/nodes/relation.h +++ b/src/include/nodes/relation.h @@ -47,15 +47,16 @@ typedef struct QualCost /* * Costing aggregate function execution requires these statistics about - * the aggregates to be executed by a given Agg node. Note that transCost - * includes the execution costs of the aggregates' input expressions. + * the aggregates to be executed by a given Agg node. Note that the costs + * include the execution costs of the aggregates' argument expressions as + * well as the aggregate functions themselves. */ typedef struct AggClauseCosts { int numAggs; /* total number of aggregate functions */ - int numOrderedAggs; /* number that use DISTINCT or ORDER BY */ + int numOrderedAggs; /* number w/ DISTINCT/ORDER BY/WITHIN GROUP */ QualCost transCost; /* total per-input-row execution costs */ - Cost finalCost; /* total costs of agg final functions */ + Cost finalCost; /* total per-aggregated-row costs */ Size transitionSpace; /* space for pass-by-ref transition data */ } AggClauseCosts; |