Function comparePartitions

backend/plugin/schema/differ.go:1322–1367

comparePartitions compares two lists of partitions.

(engine storepb.Engine, oldPartitions, newPartitions []*storepb.TablePartitionMetadata)

// comparePartitions compares two lists of partitions.
func comparePartitions(engine storepb.Engine, oldPartitions, newPartitions []*storepb.TablePartitionMetadata) []*PartitionDiff {
	var changes []*PartitionDiff

	oldPartMap := make(map[string]*storepb.TablePartitionMetadata)
	for _, part := range oldPartitions {
		oldPartMap[part.Name] = part
	}

	newPartMap := make(map[string]*storepb.TablePartitionMetadata)
	for _, part := range newPartitions {
		newPartMap[part.Name] = part
	}

	// Check for dropped partitions
	for partName, oldPart := range oldPartMap {
		if _, exists := newPartMap[partName]; !exists {
			changes = append(changes, &PartitionDiff{
				Action:       MetadataDiffActionDrop,
				OldPartition: oldPart,
			})
		}
	}

	// Check for new and modified partitions
	for partName, newPart := range newPartMap {
		oldPart, exists := oldPartMap[partName]
		if !exists {
			changes = append(changes, &PartitionDiff{
				Action:       MetadataDiffActionCreate,
				NewPartition: newPart,
			})
		} else if !partitionsEqual(engine, oldPart, newPart) {
			// Drop the old partition and recreate the new one instead of altering
			changes = append(changes, &PartitionDiff{
				Action:       MetadataDiffActionDrop,
				OldPartition: oldPart,
			})
			changes = append(changes, &PartitionDiff{
				Action:       MetadataDiffActionCreate,
				NewPartition: newPart,
			})
		}
	}

	return changes
}

// compareTriggers compares two lists of triggers.
func compareTriggers(oldTriggers, newTriggers []*storepb.TriggerMetadata) []*TriggerDiff {