This is special case , plese Take a look carefully the below link and read at last paragraph at the bottom of this comment, let everyone share idea, We will go with B, C https://cloud.google.com/bigtable/docs/schema-design#time-based Don't use a timestamp by itself or at the beginning of a row key, because this will cause sequential writes to be pushed onto a single node, creating a hotspot. If you usually retrieve the most recent records first, you can use a reversed timestamp in the row key by subtracting the timestamp from your programming language's maximum value for long integers (in Java, java.lang.Long.MAX_VALUE). With a reversed timestamp, the records will be ordered from most recent to least recent.

B is the answer. https://cloud.google.com/bigtable/docs/schema-design#time-based If you usually retrieve the most recent records first, you can use a reversed timestamp in the row key by subtracting the timestamp from your programming language's maximum value for long integers (in Java, java.lang.Long.MAX_VALUE). With a reversed timestamp, the records will be ordered from most recent to least recent.

B is a correct answer because "you need to access only the most recent stock prices" "If you usually retrieve the most recent records first, you can use a reversed timestamp in the row key by subtracting the timestamp from your programming language's maximum value for long integers (in Java, java.lang.Long.MAX_VALUE). With a reversed timestamp, the records will be ordered from most recent to least recent." https://cloud.google.com/bigtable/docs/schema-design#time-based

B. One unique table for all indices, reverse timestamp as row key: A single table for all indices keeps the structure simple. Using a reverse timestamp as part of the row key ensures that the most recent data comes first in the sorted order. This design is beneficial for quickly accessing the latest data. For example: you can convert the timestamp to a string and format it in reverse order, like "yyyyMMddHHmmss", ensuring newer dates and times are sorted lexicographically before older ones.

Correct Is B

Option B using reverse timestamp only, this is not the answer. the right answer should be using the index and revers timestamp as the row key. So, Option D is the only answer, because not A,B,C .

https://cloud.google.com/bigtable/docs/schema-design#row-keys - If you usually retrieve the most recent records first, you can use a reversed timestamp B it is.

A is the answer

the answer relieves on whether the application need to access the whole indexes at the same time or not. If yes then is B, if no is A. in mind the answer is yes, so B makes more sense: I retrieve all the list at the same time.

https://cloud.google.com/bigtable/docs/schema-design#time-based If you usually retrieve the most recent records first, you can use a reversed timestamp in the row key by subtracting the timestamp from your programming language's maximum value for long integers (in Java, java.lang.Long.MAX_VALUE). With a reversed timestamp, the records will be ordered from most recent to least recent.

"access the data with the simplest query"

yes reverse time stamp is recommended to prevent hot spot. But our query pattern is we need most recent record the is easy when you use Timestamp and Also option a stating that our row key not starting with time stamp which is index#timestamp and which is the most efficient way for this scenario.

Reversed timestamp will definitely help here.

Answer A: I checked on other website and chatgpt also suggested A, to use index per stock and timestamp.

The key here is "only the most recent stock prices". Doesn't talk about accessing a specific index - so answer should be B

https://cloud.google.com/bigtable/docs/schema-design#row-keys-avoid

Answer is B: https://stackoverflow.com/questions/65487550/bigtable-reverse-timestamp-advantage-over-regular-timestamp You want to access the MOST recent stock price First. Reverse Timestamp