How to read large files? Is there a way to read them in a streaming?

[Zzaniu]

Big file read, then memory burst

let mut book = umya_spreadsheet::reader::xlsx::lazy_read(self.file_path.as_ref())?;
let cell = book
            .get_lazy_read_sheet_cells(&sheet_index)
            .map_err(|e| anyhow!("{e}"))?;
let v = cell.get_cell_value((1, index)).get_value();
...

memory allocation of 17867735056 bytes failed

[Zzaniu]

I solved this problem with calamine, but calamine can only be read and not written. I really hope that umya_spreadsheet will solve this problem

[MathNya]

@Zzaniu
Thank you for contacting us.
We are sorry, but we may not be able to meet your expectations.
We are aware that umya-spreadsheet consumes more memory than other libraries.
However, we have not found a solution at this time.
I think a solution will be quite a while away.

[BharathIO]

@MathNya I am also looking for same. Any work arounds at this moment to support streaming? Appreciate your response

I specifically need Streaming while writing rows to Excel workbook sheet,

[MathNya]

@BharathIO
When umya-spreadsheet updates a cell, it deserializes all cells in the sheet.
Because of this implementation, it is not currently possible to achieve the expected behavior.

[BharathIO]

Ok. Thanks for the update @MathNya .

When i am writing around 17k records into sheet, i observed it is consuming more memory. Any way i can do to use it less memory? Please share your thoughts

I observed it consumed 800 to 900 MB of RAM while writing 17k records

[BharathIO]

Is there any way to write custom serializer/deserializer for my usecase to process 17k records?

[schungx]

17k records in memory is probably going to take large amounts of RAM by themselves.

[BharathIO]

But when i observed, while using other libraries like xlsxwriter or so, it did not consume large amount of RAM.

umya-spreadsheet library has lot more features compared to other libraries, only issue is with large amount of RAM consumption and high CPU Utilization. Any workarounds at this moment?

[schungx]

umya-spreadsheet library has lot more features compared to other libraries, only issue is with large amount of RAM consumption and high CPU Utilization. Any workarounds at this moment?

I believe there are venues to reduce the memory footprint of many data types, but essentially more features = more data types to keep track of. Therefore it is not always avoidable.

[schungx]

Try my PR to see how much it reduces...

#242

[BharathIO]

Try my PR to see how much it reduces...

#242

Great, i could see a bigger change now in terms of Memory & CPU utilization. I will validate few more use cases and post my observations here.

[schungx]

@BharathIO would be interested to know the memory usage in the new version.