rsbd_lab_1

mkdir -p /var/lib/pgsql/rsbd2
initdb /var/lib/pgsql/rsbd2
pg_ctl -D /var/lib/pgsql/rsbd2 -l logfile start
---
create server rsbd1 foreign data wrapper postgres_fdw options (host 'localhost', port '5432', dbname 'postgres');
create user mapping for postgres server rsbd1 options (user 'postgres')
import foreign schema public limit to (pracownicy) from server rsbd1 into public;
---
select adres from zespoly where id_zesp=10;
   adres
------------
 PIOTROWO 1
(1 row)

select placa_pod from pracownicy where id_prac=100;
 placa_pod
-----------
    999.00
(1 row)

===============
=3==Transakcje=
===============

1) -> terminal 1 odpowiedizalny za baze 1
2) -> terminal 2 odpowiedizalny za baze 2
3) -> terminal pomocniczy
-------------------

1) begin;
1) update pracownicy set placa_pod=777 where id_prac=100;
2) begin;
2) update zespoly set adres='PIOTROWO 88' where id_zesp=10;
1) PREPARE TRANSACTION 'distributed-transaction02-rsbd1';
2) PREPARE TRANSACTION 'distributed-transaction02-rsbd2';
3) pg_ctl -D /var/lib/pgsql/rsbd2  stop
3) pg_ctl -D /var/lib/pgsql/rsbd1  stop

3) pg_ctl -D /var/lib/pgsql/rsbd1  start
3) pg_ctl -D /var/lib/pgsql/rsbd2  start

1) select * from pg_prepared_xacts;
 transaction |  gid  |           prepared            |  owner   | database
-------------+-------+-------------------------------+----------+----------
        1778 | 02-01 | 2019-10-10 10:07:49.471017-04 | postgres | postgres
(1 row)2) select * from pg_prepared_xacts;
 transaction |  gid  |           prepared            |  owner   | database
-------------+-------+-------------------------------+----------+----------
        1769 | 02-02 | 2019-10-10 10:07:59.102974-04 | postgres | postgres
(1 row)

==================
=4==Zakleszczenie=
==================

1) begin;
1) select placa_pod from pracownicy where id_prac=100 for update nowait;
1) update pracownicy set placa_pod=placa_pod+10 where id_prac=100;
2) begin;
2) select adres from zespoly where id_zesp=10 for update nowait;
2) update zespoly set adres='PIOTROWO 88' where id_zesp=10;
1) select adres from zespoly where id_zesp=10 for update nowait;
1) update zespoly set adres='PIOTROWO 77' where id_zesp=10;
2) select placa_pod from pracownicy where id_prac=100 for update nowait;
2) update pracownicy set placa_pod=placa_pod+10 where id_prac=100 for update nowait;

============
=5==Repliki=
============

1) select * from zespoly_replika;
wady ? po kazdej aktualizacji trzeba odsiwezyc zawartosc materializowanych perpspektyw

curl https://install.citusdata.com/community/rpm.sh | sudo bash
sudo yum install -y pg_cron_11

                                                              81,0-1        Bot