diff options
Diffstat (limited to 'src/backend/utils/adt/selfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/selfuncs.c | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 0c8c05f6c2e..60549d76b7a 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -3443,13 +3443,13 @@ estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows, * expression, treat it as a single variable even if it's really more * complicated. * - * XXX This has the consequence that if there's a statistics on the - * expression, we don't split it into individual Vars. This affects - * our selection of statistics in estimate_multivariate_ndistinct, - * because it's probably better to use more accurate estimate for each - * expression and treat them as independent, than to combine estimates - * for the extracted variables when we don't know how that relates to - * the expressions. + * XXX This has the consequence that if there's a statistics object on + * the expression, we don't split it into individual Vars. This + * affects our selection of statistics in + * estimate_multivariate_ndistinct, because it's probably better to + * use more accurate estimate for each expression and treat them as + * independent, than to combine estimates for the extracted variables + * when we don't know how that relates to the expressions. */ examine_variable(root, groupexpr, 0, &vardata); if (HeapTupleIsValid(vardata.statsTuple) || vardata.isunique) @@ -3918,7 +3918,7 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel, if (!rel->statlist) return false; - /* look for the ndistinct statistics matching the most vars */ + /* look for the ndistinct statistics object matching the most vars */ nmatches_vars = 0; /* we require at least two matches */ nmatches_exprs = 0; foreach(lc, rel->statlist) @@ -3964,7 +3964,7 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel, continue; } - /* expression - see if it's in the statistics */ + /* expression - see if it's in the statistics object */ foreach(lc3, info->exprs) { Node *expr = (Node *) lfirst(lc3); @@ -4053,7 +4053,7 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel, if (!AttrNumberIsForUserDefinedAttr(attnum)) continue; - /* Is the variable covered by the statistics? */ + /* Is the variable covered by the statistics object? */ if (!bms_is_member(attnum, matched_info->keys)) continue; @@ -4075,7 +4075,7 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel, if (found) continue; - /* expression - see if it's in the statistics */ + /* expression - see if it's in the statistics object */ idx = 0; foreach(lc3, matched_info->exprs) { @@ -5252,7 +5252,7 @@ examine_variable(PlannerInfo *root, Node *node, int varRelid, { HeapTuple t = statext_expressions_load(info->statOid, pos); - /* Get index's table for permission check */ + /* Get statistics object's table for permission check */ RangeTblEntry *rte; Oid userid; @@ -5276,8 +5276,8 @@ examine_variable(PlannerInfo *root, Node *node, int varRelid, /* * For simplicity, we insist on the whole table being * selectable, rather than trying to identify which - * column(s) the statistics depends on. Also require all - * rows to be selectable --- there must be no + * column(s) the statistics object depends on. Also + * require all rows to be selectable --- there must be no * securityQuals from security barrier views or RLS * policies. */ |