Build tested: 1.4.0-1
I installed MCS using S3 local storage and switched to S3 cloud storage, MCS still works. This is probably because I tested only a small table and data is in local cache. I have seen queries failed due to missing objects.
Since MCS does not support such S3 storage type switching, we should do
1. postConfigure should save the storage type (localStorage or S3) in the ColumnStore.xml file
2. during subsequent system startup, it should check to see if storage type in storageManager.cnf matches that in ColumnStore.xml. If not matched, error should be return and system should not come up.
3. even better, we should keep track of the region and bucket name (for AWS)
The following are the steps for my test
1. installed MCS using S3 local storage
2. created and load orders table
3. executed query
5. modified storagemanager.cnf to use AWS S3 storage (AWS S3 bucket is empty)
7. exeuted query (query still worked)
8. data files appeared in AWS S3 bucket