Walsender getting klilled, ERROR: out of memory in server logs

Hi All,

I have a table test(id int, lobcol bytea), the REPLICA IDENTITY setting of
the table is set to FULL. We are using the test_decoding plugin for logical
decoding. We inserted a record with lobcol size of 256 MB. While updating
that record with another lobcol value of 256 MB, we found in the server
logs that the corresponding walsender process keeps getting killed and it
shows 'out of memory' and this particular message repeats.

[11349] ERROR: out of memory

DETAIL: Cannot enlarge string buffer containing 1073741822 bytes by 1 more
bytes.

[11587] ERROR: out of memory

DETAIL: Cannot enlarge string buffer containing 1073741822 bytes by 1 more
bytes.

Can you please help me understand the cause of this issue ? If there are
any relevant documentation links or any possible workaround please share it.

Thank you,

Regards,
Subhrajit