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December 4

Excel Question

Assume an Excel spreadsheet has two columns, ID and Date. Every entry in the ID column has a corresponding entry in the date column and vice versa. Each ID occurs once or more. Each ID can be associated with a number of different dates (including potentially the same date more than once). What is the quickest way to produce a table of all distinct IDs and the earliest date associated with that ID in the original table? Thanks 195.89.101.130 (talk) 11:57, 4 December 2023 (UTC)[reply]

Pivot table. There is no quicker way. Click insert pivot table. Select the ID for the group. Select the date and "min" as the function. Done. 97.82.165.112 (talk) 14:07, 4 December 2023 (UTC)[reply]

Can a computer do A and B, but not both at the same time?

Do we have any situations in computing where computers cannot do 2 things at the same time? I think computers have set up architectures or environments that it will only do things 1 after the other, to prevent it from doing 2 at the same time. There's also the concept of deadlock, which might play a role. 170.76.231.162 (talk) 19:10, 4 December 2023 (UTC).[reply]

Welcome to the reference desk. To answer your question, it is possible for computers to use separate threads to execute multiple commands or calculations simultaneously. See parallel computing and concurrent computing for more info. Sincerely, Novo Tape (She/Her)^{My Talk Page} 19:13, 4 December 2023 (UTC)[reply]

If the processor has multiple cores, these can execute different threads simultaneously. If the processor is a single-core CPU, it can at any instant of time be executing only a single thread; any other threads under execution are temporarily suspended. However, the operating system can switch tasks so quickly that for practical purposes it may seem as if the corresponding processes proceed simultaneously. --Lambiam 10:47, 6 December 2023 (UTC)[reply]

Note that the other resources will need to be sufficient as well. Memory/RAM is the most obvious if whatever is being done requires nearly all the memory to work and to be clear I don't just mean allocated but it cannot function without whatever it is in memory then another task with even moderate memory needs can't really be executed simultaneously. The OS can try to swap whatever it is out of memory but even with the fastest NVMe SSDs if both tasks really need all that memory constantly it's just not going to work very well at all. Nil Einne (talk) 15:04, 10 December 2023 (UTC)[reply]