Insights transactions details shows only 1 blocking txn

[j82w]

It's possible that a single transaction can be blocked by multiple transactions. The insights transaction details page and sql activity active transaction details page only show one blocking transaction. It could be blocked on completely different table and statements. This might make it challenging as the current ui makes the assumption there would only ever be 1 blocked schema/database/table.

This shows that there are 2 txn ids blocking 8a5f..

The insights transaction details page only shows first blocking txn id instead of both in the table.

To reproduce:
Session1:

CREATE TABLE t (id string, s string);
begin;
INSERT INTO t (id, s) VALUES ('234', 'valueSession1');

Session2:

begin;
UPDATE t SET s = 'valueSession2' where id = '2345';

Wait several seconds then continue:
Session1:

end;

Session3:

UPDATE t SET s = 'valueSession3' where id = '2345';

Wait several seconds then continue:
Session2:

end;

Jira issue: CRDB-19754