Bytea fields download automatically when selecting tables

[benlowry]

If you select a table it automatically opens the rows view, when it has bytea data pgweb downloads it all and is unresponsive till it finishes, with no notification of what's going on or how long to remain.

I think bytea fields should have a link to download, ideally with the size if that's possible.

Second best would be a progress bar or something, that would also stop the browser messages about an unresponsive tab.

[sosedoff]

Please provide a sample SQL file so that i can test and fix the problem.

[benlowry]

create table tmp (
    blob bytea
);

insert into tmp(blob) values('\xABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789 ABCDEF0123456789')

I've been digging into the code, I don't know golang but I've managed to tentatively identify a bytea field and substitute its size, it's possible I'm not identifying it properly but maybe this gives you a head start. I was trying to look for the '\x' that byte data starts with (I think always but again not sure).

func (res *Result) PrepareBytea() {
        for i, row := range res.Rows {
                for j, col := range row {
            t := reflect.TypeOf(col).Kind()
            if(t != reflect.String) {
                continue
            }
            str := col.(string)
            if str[0] == 255 {
                res.Rows[i][j] = len(str)
            }
        }
    }
}

[sosedoff]

Thanks, i will check on this issues once i get some free time.

[sosedoff]

I just created a table from your example using pgweb 0.9.3 (latest) on OSX (chrome) and this is what i got so far:

Nothing was downloaded automatically. Also tried Safari and Firefox, both work. What OS and browser are you using?

[benlowry]

That is what you downloaded, you just need to provide a lot more to see the effect, try some 10s of megabytes in the bytea value or reproduce the row 1000s of times and you will probably see your browser start straining. I should have mentioned this I just didn't want to put an incredibly massive example. In our case we have a table with about 2000 rows and a small amount of binary data for each row that totals 150 megabytes.

[sosedoff]

Ah i see what you mean now. What is the behavior you expect?

[benlowry]

Ideally clicking the tables wouldn't include the raw data at all, that could be solved by:

• only returning the bytea data when selecting it explicitly, either dropping it at the server or preferably not selecting it
• a way to edit the 'you selected the table' query so you can exclude columns

[benlowry]

This was pretty much fixed for me by limiting the number of rows returned when clicking a table.

Thanks for all your wonderful work @sosedoff!