Until now, I have been using import command to import data and have been saving --last-value in the default metastore.
1. What to specify for --last-value initially in the import command for incremental import based on last modified value. I see it's 0 for append mode but what should that be in lastmodified mode?
2. I have a table I need to import data incrementally from but the modified_at field of this table is stored in another table referenced via foreign key. Now, since there are multiple tables involved here, I understand that I will need to use free query form but how exactly does it fetch --last-value from metastore? I of course am not going to hard code the last value in free query.
Also, how do I provide modified_at column from this referenced table?