No matched schema for {"_id":"...","doc":{...}

Question

When using the SDP to extract data from Cloudant and populate dashDB, I occasionally see error messages in the dashdb "XXXX_OVERFLOW" table that look like this:

No matched schema for {"_id":"...","doc":{...}

Questions

1. What does this error mean?
2. How can I fix it?

Answer 1

There are two main phases to the SDP process:

• Schema analysis
• Data import

In the schema analysis phase, the SDP analyses a sample of documents in Cloudant and uses the document structures of the sample to infer the target schema in dashDB.

1. The above error is encountered when the SDP tries to import a document with a schema that it did not see during the SDP analysis stage.

2. The only option to resolve this is to increase the sample size used during schema discovery to unlimited.