Re: Update concurrency

=?utf-8?Q?Sylvain_D=C3=A9ve?= <sylvain(dot)deve(at)protonmail(dot)com> writes:
> # JSONB update for a single selected row and column.
> # 'column' and 'select_row' are determined with the parameters 'data' and 'path'.
> command = (
> f"""UPDATE MY_TABLE SET """
> f"""{column} = jsonb_merge({column}, %s) """
> f"""WHERE {select_row};"""
> )

> When called twice in a row, this call leads to the error (at "cur.execute"):
> psycopg2.errors.InternalError_: tuple concurrently updated

That error should be pretty hard to reach from user code, and certainly
two successive UPDATEs ought not have anything to do with it. I think
there is something you're not telling us about the context. Does this
table have any triggers, weird constraints, or the like? What is the
actual WHERE clause (ie, I wonder if you have simplified away some
relevant query detail)? What PG version is this exactly?

regards, tom lane