diff options
Diffstat (limited to 'src/backend/catalog/partition.c')
| -rw-r--r-- | src/backend/catalog/partition.c | 64 |
1 files changed, 49 insertions, 15 deletions
diff --git a/src/backend/catalog/partition.c b/src/backend/catalog/partition.c index 3ee2b2a5aaf..ff55f9c1b84 100644 --- a/src/backend/catalog/partition.c +++ b/src/backend/catalog/partition.c @@ -741,37 +741,68 @@ check_new_partition_bound(char *relname, Relation parent, Node *bound) boundinfo->strategy == PARTITION_STRATEGY_RANGE); /* - * Find the greatest index of a range bound that is less - * than or equal with the new lower bound. + * Firstly, find the greatest range bound that is less + * than or equal to the new lower bound. */ off1 = partition_bound_bsearch(key, boundinfo, lower, true, &equal); /* - * If equal has been set to true, that means the new lower - * bound is found to be equal with the bound at off1, - * which clearly means an overlap with the partition at - * index off1+1). - * - * Otherwise, check if there is a "gap" that could be - * occupied by the new partition. In case of a gap, the - * new upper bound should not cross past the upper - * boundary of the gap, that is, off2 == off1 should be - * true. + * off1 == -1 means that all existing bounds are greater + * than the new lower bound. In that case and the case + * where no partition is defined between the bounds at + * off1 and off1 + 1, we have a "gap" in the range that + * could be occupied by the new partition. We confirm if + * so by checking whether the new upper bound is confined + * within the gap. */ if (!equal && boundinfo->indexes[off1 + 1] < 0) { off2 = partition_bound_bsearch(key, boundinfo, upper, true, &equal); + /* + * If the new upper bound is returned to be equal to + * the bound at off2, the latter must be the upper + * bound of some partition with which the new + * partition clearly overlaps. + * + * Also, if bound at off2 is not same as the one + * returned for the new lower bound (IOW, off1 != + * off2), then the new partition overlaps at least one + * partition. + */ if (equal || off1 != off2) { overlap = true; - with = boundinfo->indexes[off2 + 1]; + + /* + * The bound at off2 could be the lower bound of + * the partition with which the new partition + * overlaps. In that case, use the upper bound + * (that is, the bound at off2 + 1) to get the + * index of that partition. + */ + if (boundinfo->indexes[off2] < 0) + with = boundinfo->indexes[off2 + 1]; + else + with = boundinfo->indexes[off2]; } } else { + /* + * Equal has been set to true and there is no "gap" + * between the bound at off1 and that at off1 + 1, so + * the new partition will overlap some partition. In + * the former case, the new lower bound is found to be + * equal to the bound at off1, which could only ever + * be true if the latter is the lower bound of some + * partition. It's clear in such a case that the new + * partition overlaps that partition, whose index we + * get using its upper bound (that is, using the bound + * at off1 + 1). + */ overlap = true; with = boundinfo->indexes[off1 + 1]; } @@ -1957,8 +1988,8 @@ partition_bound_cmp(PartitionKey key, PartitionBoundInfo boundinfo, } /* - * Binary search on a collection of partition bounds. Returns greatest index - * of bound in array boundinfo->datums which is less or equal with *probe. + * Binary search on a collection of partition bounds. Returns greatest + * bound in array boundinfo->datums which is less than or equal to *probe * If all bounds in the array are greater than *probe, -1 is returned. * * *probe could either be a partition bound or a Datum array representing @@ -1990,6 +2021,9 @@ partition_bound_bsearch(PartitionKey key, PartitionBoundInfo boundinfo, { lo = mid; *is_equal = (cmpval == 0); + + if (*is_equal) + break; } else hi = mid - 1; |