diff options
Diffstat (limited to 'src/backend/optimizer/util/pathnode.c')
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 00052f5c846..78aee5df08e 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -128,11 +128,11 @@ compare_fractional_path_costs(Path *path1, Path *path2, * * The fuzz_factor argument must be 1.0 plus delta, where delta is the * fraction of the smaller cost that is considered to be a significant - * difference. For example, fuzz_factor = 1.01 makes the fuzziness limit + * difference. For example, fuzz_factor = 1.01 makes the fuzziness limit * be 1% of the smaller cost. * * The two paths are said to have "equal" costs if both startup and total - * costs are fuzzily the same. Path1 is said to be better than path2 if + * costs are fuzzily the same. Path1 is said to be better than path2 if * it has fuzzily better startup cost and fuzzily no worse total cost, * or if it has fuzzily better total cost and fuzzily no worse startup cost. * Path2 is better than path1 if the reverse holds. Finally, if one path @@ -190,9 +190,9 @@ compare_path_costs_fuzzily(Path *path1, Path *path2, double fuzz_factor) * and save them in the rel's cheapest-path fields. * * Only unparameterized paths are considered candidates for cheapest_startup - * and cheapest_total. The cheapest_parameterized_paths list collects paths + * and cheapest_total. The cheapest_parameterized_paths list collects paths * that are cheapest-total for their parameterization (i.e., there is no - * cheaper path with the same or weaker parameterization). This list always + * cheaper path with the same or weaker parameterization). This list always * includes the unparameterized cheapest-total path, too. * * This is normally called only after we've finished constructing the path @@ -294,8 +294,8 @@ set_cheapest(RelOptInfo *parent_rel) * * There is one policy decision embedded in this function, along with its * sibling add_path_precheck: we treat all parameterized paths as having - * NIL pathkeys, so that they compete only on cost. This is to reduce - * the number of parameterized paths that are kept. See discussion in + * NIL pathkeys, so that they compete only on cost. This is to reduce + * the number of parameterized paths that are kept. See discussion in * src/backend/optimizer/README. * * The pathlist is kept sorted by total_cost, with cheaper paths @@ -358,7 +358,7 @@ add_path(RelOptInfo *parent_rel, Path *new_path) p1_next = lnext(p1); /* - * Do a fuzzy cost comparison with 1% fuzziness limit. (XXX does this + * Do a fuzzy cost comparison with 1% fuzziness limit. (XXX does this * percentage need to be user-configurable?) */ costcmp = compare_path_costs_fuzzily(new_path, old_path, 1.01); @@ -531,7 +531,7 @@ add_path(RelOptInfo *parent_rel, Path *new_path) * and have lower bounds for its costs. * * Note that we do not know the path's rowcount, since getting an estimate for - * that is too expensive to do before prechecking. We assume here that paths + * that is too expensive to do before prechecking. We assume here that paths * of a superset parameterization will generate fewer rows; if that holds, * then paths with different parameterizations cannot dominate each other * and so we can simply ignore existing paths of another parameterization. @@ -942,7 +942,7 @@ create_append_path(RelOptInfo *rel, List *subpaths, Relids required_outer) * Compute rows and costs as sums of subplan rows and costs. We charge * nothing extra for the Append itself, which perhaps is too optimistic, * but since it doesn't do any selection or projection, it is a pretty - * cheap node. If you change this, see also make_append(). + * cheap node. If you change this, see also make_append(). */ pathnode->path.rows = 0; pathnode->path.startup_cost = 0; @@ -1491,7 +1491,7 @@ translate_sub_tlist(List *tlist, int relid) * * colnos is an integer list of output column numbers (resno's). We are * interested in whether rows consisting of just these columns are certain - * to be distinct. "Distinctness" is defined according to whether the + * to be distinct. "Distinctness" is defined according to whether the * corresponding upper-level equality operators listed in opids would think * the values are distinct. (Note: the opids entries could be cross-type * operators, and thus not exactly the equality operators that the subquery @@ -1612,7 +1612,7 @@ query_is_distinct_for(Query *query, List *colnos, List *opids) * distinct_col_search - subroutine for query_is_distinct_for * * If colno is in colnos, return the corresponding element of opids, - * else return InvalidOid. (We expect colnos does not contain duplicates, + * else return InvalidOid. (We expect colnos does not contain duplicates, * so the result is well-defined.) */ static Oid @@ -2005,10 +2005,10 @@ create_hashjoin_path(PlannerInfo *root, /* * A hashjoin never has pathkeys, since its output ordering is - * unpredictable due to possible batching. XXX If the inner relation is + * unpredictable due to possible batching. XXX If the inner relation is * small enough, we could instruct the executor that it must not batch, * and then we could assume that the output inherits the outer relation's - * ordering, which might save a sort step. However there is considerable + * ordering, which might save a sort step. However there is considerable * downside if our estimate of the inner relation size is badly off. For * the moment we don't risk it. (Note also that if we wanted to take this * seriously, joinpath.c would have to consider many more paths for the @@ -2035,7 +2035,7 @@ create_hashjoin_path(PlannerInfo *root, * same parameterization level, ensuring that they all enforce the same set * of join quals (and thus that that parameterization can be attributed to * an append path built from such paths). Currently, only a few path types - * are supported here, though more could be added at need. We return NULL + * are supported here, though more could be added at need. We return NULL * if we can't reparameterize the given path. * * Note: we intentionally do not pass created paths to add_path(); it would @@ -2067,7 +2067,7 @@ reparameterize_path(PlannerInfo *root, Path *path, /* * We can't use create_index_path directly, and would not want * to because it would re-compute the indexqual conditions - * which is wasted effort. Instead we hack things a bit: + * which is wasted effort. Instead we hack things a bit: * flat-copy the path node, revise its param_info, and redo * the cost estimate. */ |