DADA2 rep seqs have strange names. Why?

[Moon]

And I am also curious about the merge-seqs.

You can see the name of these produced rep-seqs (by DADA2) is really strange…

Do the step of merge-seqs merge these seqs by name? or by the sequence? Will this step lead to unnecessary redundancy?

[ChrisKeefe]

Split from here:

Errors in the pipeline of DADA2, Fearture-table merge-seqs, and phylogeny align-to-tree-mafft-fasttree.

Thanks for putting together such a clear and detailed question, @Moon! Good sleuthing ! This is, indeed, an out of memory error. Here’s an experiment you can try. Sometimes when parallelizing processes, each thread contributes a significant amount of memory usage. If you’re running out of memory, try decreasing the number of threads to 4. If it still gives you OOM errors, you can try dropping the number of threads even farther. Overall, this will likely mean a longer run time…

[ChrisKeefe]

Are the "strange names" you're talking about these Feature IDs?

https:/uploads/qiime21/original/2X/a/a42e94322e23e4e37daea30f83abbd169a64e8b7.png

Plugins like DADA2 work with the sequences themselves; the Feature IDs are just unique identifiers that are (usually) much shorter than the sequences themselves, so they're easier to display and discuss.

Incidentally, if you have questions about DADA2, the paper and docs are both great resources.

[Moon]

Thank you! I get it!