Are there any negative ramifications when adding a field to existing database input?

[dirtebird]

I have an existing database input that is reading from an Oracle database.  Existing Dashboard A uses that database input. 

I want to use the same database input on a new Dashboard B, but to do so I would need to include one additional field in the SELECT statement of the database input.  It wouldn't change how many rows are returned by the query (no select distincts), and no additional joins are needed.  Are there any negative ramifications of doing this, or am I good to go?  We only have a PROD environment, so I want to be extra cautious in making any changes.

[richgalloway · Accepted solution]

It depends.

It depends on how Dashboard A uses the fields in the database input.  If there is a fields command early in each query then you're golden because the dashboard (mostly) won't even notice the new field.  I say "mostly" because there will be some (probably minor) performance impact from carrying around the new field until the first fields or other transforming command discards it.  The degree of impact will depend on the size of the new field.

It depends on whether the dashboard uses the foreach command without first limiting the fields in the query.  A command like | foreach * [ do stuff ] may have unexpected results when a new field is added.

It depends on how Dashboard A searches for data.  If a query looks for a literal string without a field name (index=foo "bar") then it may produce unexpected results if that value exists in the new field.