Error: Schema changed for Timestamp field (additional)

2
votes

I am getting an error message when I query a specific table in my data set that has a nullable timestamp field. In the BigQuery web tool, I run simple query, e.g.:

SELECT * FROM [reztrack.201401] LIMIT 100

The result I get is: Error: Schema changed for Timestamp field date

Example Job ID: esiteisthebomb:job_6WKi7ZhSi8D_Ewr8b5rKV-a5Eac

This is the exact same issue that was noted here: Error: Schema changed for Timestamp field.

Also logged this under: https://code.google.com/p/google-bigquery/issues/detail?id=307 but I was unsure since it said we should be logging everything in Stackoverlfow.

Any information on how to fix this for this or other tables would be greatly appreciated.

Note: The original answer states to contact google support, but Google support for BigQuery was moved to StackOverflow. Therefore I assume that means to open it as a new question in hopes the engineers will respond.

1
google-bigquery

1 Answers

2
votes

BigQuery recently improved the representation of its internal timestamp format (there had previously been a lot of cases where timestamps broke in strange ways and this change should fix that). Your table still was using the old timestamp format, and you tickled a bug in the old format when schemas changed (in this case, the field went from REQUIRED to OPTIONAL).

We have an automated process that coalesces tables to make their storage more efficient. I scheduled this to run over your table, and have verified that it has rewritten your table using the new timestamp format.

You should now be able to query this field of your table without further problems.