When I insert value to a cell in bigtable, it doesn't overwrite the previous value but instead just add the same value to the same column identifier in the same row. The only difference is the timestamp.
Is this normal? The GC policy on my table is default so I expect it to only retain 1 version of my data. Am I misunderstanding something?
common:delete_flag @ 2018/03/05-18:19:21.638000
"0"
common:delete_flag @ 2018/03/05-19:51:52.933000
"0"
common:delete_flag @ 2018/03/05-18:34:09.517000
"0"
common:delete_flag @ 2018/03/05-18:28:21.614000
"0"
common:delete_flag @ 2018/03/05-18:30:41.711000
"0"
Edit: Maybe this is my answer https://stackoverflow.com/a/46861250/3398347?
Your edit has it right. Bigtable garbage collection happens opportunistically in the background, so more than one version could be kept around at any point in time.
Be sure to use filters to restrict the results of a Read operation, to ensure that you don't see more data than you require.