Por ejemplo, mi postgresql-main.log contiene entradas como las siguientes:

 process 20234 session 5901502e.4f0a vtransaction transaction 0 : LOG: connection received: host=[local] process 20234 session 5901502e.4f0a vtransaction 2/1 transaction 0 : LOG: connection authorized: user=postgres database=postgres process 20234 session 5901502e.4f0a vtransaction 2/2 transaction 0 : LOG: statement: SELECT d.datname as "Name", pg_catalog.pg_get_userbyid(d.datdba) as "Owner", pg_catalog.pg_encoding_to_char(d.encoding) as "Encoding", d.datcollate as "Collate", d.datctype as "Ctype", pg_catalog.array_to_string(d.datacl, E'\n') AS "Access privileges" FROM pg_catalog.pg_database d ORDER BY 1; process 20234 session 5901502e.4f0a vtransaction transaction 0 : LOG: disconnection: session time: 0:00:00.004 user=postgres database=postgres host=[local] process 20237 session 5901502f.4f0d vtransaction transaction 0 : LOG: connection received: host=[local] process 20237 session 5901502f.4f0d vtransaction 2/3 transaction 0 : LOG: connection authorized: user=postgres database=postgres 2017-04-26 19:58:07 MDT process 20237 remote [local] session 5901502f.4f0d vtransaction 2/4 transaction 0 : LOG: statement: SELECT d.datname as "Name", pg_catalog.pg_get_userbyid(d.datdba) as "Owner", pg_catalog.pg_encoding_to_char(d.encoding) as "Encoding", d.datcollate as "Collate", d.datctype as "Ctype", pg_catalog.array_to_string(d.datacl, E'\n') AS "Access privileges" FROM pg_catalog.pg_database d ORDER BY 1; process 20237 session 5901502f.4f0d vtransaction transaction 0 : LOG: disconnection: session time: 0:00:00.002 user=postgres database=postgres host=[local]

¿Existe alguna relación entre los identificadores de transacciones virtuales 2/1 y 2/2 anteriores, ya que comparten el prefijo 2/ ?