As per this blog post http://bonesmoses.org/2016/07/29/pg-phriday-constipated-connections/ I have a question which I asked there too, but unfortunately did not receive any answer. The question is re the following claim: - Readers do not block readers. - Readers do not block writers. - Writers do not block readers. - Writers may block writers. Are the above statements true even with SET TRANSACTION SERIALIZEABLE mode. I am specifically interested in the 3rd condition (- Writers do not block readers.) thanks -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general