SQL The problem of long tables

[Mikhaylov-yv]

What's wrong? Unexpected shrinking of a table when loading from a database. Longer than > 1 000 000

I know that there is a limit on the maximum table length = 1 000 000. But I think we can be a little friendlier. We have different behavior depending on the database.

MS SQL

If table length > 1 000 000 then nothing happens. I think we can display an error message if the data could not be loaded.

Postge SQL

If the length of the table is > 1 000 000, then it greatly decreases when loading. For example, when loading a sequence of numbers from 0 to 1,000,100. We get a table of length 10.400 with a minimum value of 39.220 and a maximum value of 979.019. This is a very strange result.

I propose to discuss solutions:

1. Display an error message
2. Slicing ranges Similar to pandas based on size

How can we reproduce the problem? jupyter notebook

What's your environment?

• Operating system: win11
• Orange version: '3.35.0.dev0+3cc58b4'
• How you installed Orange: from source code

[Mikhaylov-yv]

I think this problem is related to #6414