Aws Athena View 列数限制？

Question

I seem to run into an athena view construction limitation that I cannot find any documentation on it. This is the query I run to generate the View:

CREATE OR REPLACE VIEW view1 AS
(
    SELECT * FROM table1
)

table1 only has 5 rows. If the table1 has 9334 columns, the view construction is successful. But if table1 has 9335 columns, I get the following error:

Exception: com.facebook.presto.v217.spi.PrestoException: 1 validation error detected: Value '/* Presto View: 

Which is followed by a pages-long hash. Does anyone understand what the problem/error is?

Answer 1

The problem could be that the Glue API only allows the field that stores the view metadata to be 409600 bytes, and when you add that 9335th column it becomes truncated and no longer validates when read back.

What you call "a pages-long hash" is really a base 64 encoded JSON structure containing the internal Presto representation of the view. You can figure out if my hunch is right by checking the size of the encoded string. If it's 409600 then the limit in the Glue API is the problem.