Chapter 20 PostgreSQL
psql -h localhost -U postgres pasword ```
https://askubuntu.com/questions/831262/how-to-install-pgadmin-4-in-desktop-mode-on-ubuntu
$cd pgadmin4/
$source bin/activate
$python3 lib/python3.6/site-packages/pgadmin4/pgAdmin4.py
Starting pgAdmin 4. Please navigate to http://127.0.0.1:5050 in your browser.- Where is the database data stored in filesystem?
http://veryr.com/posts/postgres-storage-location/
00:13 # l /var/lib/postgresql/10/main/base/16385/
./ 12897 2606_vm 2657 2756 3381 3602_vm
../ 12899 2607 2658 2757 3381_vm 3603
112 12900 2607_fsm 2659 2830 3394 3603_fsm
113 12902 2607_vm 2660 2830_vm 3394_fsm 3603_vm
1247 12904 2608 2661 2831 3394_vm 3604
1247_fsm 1417 2608_fsm 2662 2832 3395 3605
1247_vm 1417_vm 2608_vm 2663 2832_vm 3439 3606
1249 1418 2609 2664 2833 3439_vm 3607
1249_fsm 1418_vm 2609_fsm 2665 2834 3440 3608
1249_vm 16407 2609_vm 2666 2834_vm 3455 3609
1255 16410 2610 2667 2835 3456 3712
1255_fsm 16412 2610_fsm 2668 2836 3456_fsm 3764
1255_vm 16415 2610_vm 2669 2836_vm 3456_vm 3764_fsm
1259 16417 2611 2670 2837 3466 3764_vm
1259_fsm 16418 2611_vm 2673 2838 3466_vm 3766
1259_vm 174 2612 2674 2838_fsm 3467 3767
12870 175 2612_fsm 2675 2838_vm 3468 3997
12870_fsm 2187 2612_vm 2678 2839 3501 5002
12870_vm 2224 2613 2679 2840 3501_vm 548
12872 2224_vm 2613_vm 2680 2840_fsm 3502 549
12874 2328 2615 2681 2840_vm 3503 6102
12875 2328_vm 2615_fsm 2682 2841 3534 6102_vm
12875_fsm 2336 2615_vm 2683 2995 3541 6104
12875_vm 2336_vm 2616 2684 2995_vm 3541_fsm 6104_vm
12877 2337 2616_fsm 2685 2996 3541_vm 6106
12879 2600 2616_vm 2686 3079 3542 6106_vm
12880 2600_fsm 2617 2687 3079_fsm 3574 6110
12880_fsm 2600_vm 2617_fsm 2688 3079_vm 3575 6111
12880_vm 2601 2617_vm 2689 3080 3576 6112
12882 2601_fsm 2618 2690 3081 3576_vm 6113
12884 2601_vm 2618_fsm 2691 3085 3596 6117
12885 2602 2618_vm 2692 3118 3596_vm 826
12885_fsm 2602_fsm 2619 2693 3118_vm 3597 826_vm
12885_vm 2602_vm 2619_fsm 2696 3119 3598 827
12887 2603 2619_vm 2699 3164 3598_vm 828
12889 2603_fsm 2620 2701 3256 3599 pg_filenode.map
12890 2603_vm 2620_vm 2702 3256_vm 3600 pg_internal.init
12890_fsm 2604 2650 2703 3257 3600_fsm PG_VERSION
12890_vm 2604_vm 2651 2704 3258 3600_vm
12892 2605 2652 2753 3350 3601
12894 2605_fsm 2653 2753_fsm 3350_vm 3601_fsm
12895 2605_vm 2654 2753_vm 3351 3601_vm
12895_fsm 2606 2655 2754 3379 3602
12895_vm 2606_fsm 2656 2755 3380 3602_fsm
00:10 # du -sh /var/lib/postgresql/10/main/base/16385/
7.6M /var/lib/postgresql/10/main/base/16385/
00:10 # psql -h localhost -U postgres
Password for user postgres:
psql (10.1)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.
postgres=# select oid, datname from pg_database ;
oid | datname
-------+-----------
13035 | postgres
16385 | mydb
1 | template1
13034 | template0
(4 rows)- Create a new database
createdb -h localhost -U postgres -T template0 springfield
Postgres 中的简单压缩算法