Checking Whether Type Names Mapped to the Destination Database Are Valid

**Table 1** Checking whether type names mapped to the destination database are valid
Check Item	Whether type names mapped to the destination database are valid
Description	The type mapped to the destination end must meet the following requirements: If the destination version is 5.x, an index can support multiple types. If the destination version is 6.x or later, one index supports only one type.
Item to Be Confirmed and Handling Suggestion	Failure cause: In Elasticsearch 6.x, one index supports only one type. The recommended type name is _doc (In this way, APIs are compatible with 7.x or later). In Elasticsearch 7.x, include_type_name is set to false, and the index API formats are PUT /{index}/_doc/{id} and POST {index}/_doc. Handling suggestion: Return to the page for setting the synchronization task, edit index names and type names of the selected synchronization objects to ensure that one index supports only one type.