openGauss每日一练第21天 - 学习心得体会

学习目标：

opengauss数据库例行维护

1.使用操作系统命令和数据库工具检查实例状态

root@modb:~# su - omm
omm@modb:~$ ps -ef|grep gaussdb
omm          1     0  0 09:57 ?        00:00:01 gaussdb
omm        400   396  0 10:00 pts/0    00:00:00 grep gaussdb
omm@modb:~$ ps -Tp 1
  PID  SPID TTY          TIME CMD
    1     1 ?        00:00:00 gaussdb
    1   293 ?        00:00:00 jemalloc_bg_thd
    1   299 ?        00:00:00 gaussdb
    1   300 ?        00:00:00 syslogger
    1   301 ?        00:00:00 jemalloc_bg_thd
    1   302 ?        00:00:00 alarm
    1   303 ?        00:00:00 reaper
    1   304 ?        00:00:00 jemalloc_bg_thd
    1   350 ?        00:00:00 Spbgwriter
    1   305 ?        00:00:00 jemalloc_bg_thd
    1   349 ?        00:00:00 checkpointer
    1   353 ?        00:00:00 pagewriter
    1   354 ?        00:00:00 pagewriter
    1   351 ?        00:00:00 pagewriter
    1   352 ?        00:00:00 pagewriter
    1   355 ?        00:00:00 pagewriter
    1   356 ?        00:00:00 WALwriter
    1   358 ?        00:00:00 AVClauncher
    1   359 ?        00:00:00 Jobscheduler
    1   357 ?        00:00:00 WALwriteraux
    1   360 ?        00:00:00 asyncundolaunch
    1   361 ?        00:00:00 globalstats
    1   362 ?        00:00:00 applylauncher
    1   363 ?        00:00:00 statscollector
    1   364 ?        00:00:00 percentworker
    1   365 ?        00:00:00 ashworker
    1   366 ?        00:00:00 TrackStmtWorker
    1   367 ?        00:00:00 auditor
    1   368 ?        00:00:00 2pccleaner
    1   369 ?        00:00:00 faultmonitor
    1   370 ?        00:00:00 WLMworker
    1   371 ?        00:00:00 WLMmonitor
    1   372 ?        00:00:00 WLMarbiter
    1   373 ?        00:00:00 undorecycler
omm@modb:~$ gs_ctl status
[2022-12-14 10:00:51.460][402][][gs_ctl]: gs_ctl status,datadir is /var/lib/opengauss/data 
gs_ctl: server is running (PID: 1)
/usr/local/opengauss/bin/gaussdb
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# 
omm=# show data_directory;
     data_directory      
-------------------------
 /var/lib/opengauss/data
(1 row)

2：检查锁信息

omm=# omm=# SELECT * FROM pg_locks;
ERROR:  syntax error at or near "omm"
LINE 1: omm=# SELECT * FROM pg_locks;
        ^
omm=#   locktype  | database | relation | page | tuple | bucket | virtualxid | transactionid | classid 
omm-# | objid | objsubid | virtualtransaction |       pid       |    sessionid    |      mode       | g
omm-# ranted | fastpath |      locktag      | global_sessionid 
omm-# ------------+----------+----------+------+-------+--------+------------+---------------+---------
omm-# +-------+----------+--------------------+-----------------+-----------------+-----------------+--
omm-#        | t        | b:1e:0:0:0:7      | 0:0#0
omm-#  virtualxid |          |          |      |       |        | 9/59       |               |         
omm-# |       |          | 9/59               | 281471024856304 | 281471024856304 | ExclusiveLock   | t
omm-# -------+----------+-------------------+------------------
omm-#  relation   |    16384 |    12010 |      |       |        |            |               |         
omm-# |       |          | 11/30              | 281470852431088 | 281470852431088 | AccessShareLock | t
omm-#        | t        | 4000:2eea:0:0:0:0 | 0:0#0
omm-#  virtualxid |          |          |      |       |        | 11/30      |               |         
omm-# |       |          | 11/30              | 281470852431088 | 281470852431088 | ExclusiveLock   | t
omm-#        | t        | 9:3b:0:0:0:7      | 0:0#0
(3 rows)omm-#

3查看数据库版本、日志信息

omm=# SELECT version();
                                                                        version                  
                                                      
-------------------------------------------------------------------------------------------------
------------------------------------------------------
 (openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr   on aarch64-u
nknown-linux-gnu, compiled by g++ (GCC) 7.3.0, 64-bit
(1 row)

omm=# \! ls /var/lib/opengauss/data/pg_log
postgresql-2022-12-14_095741.log  postgresql-2022-12-14_095752.log

4检查应用连接数、查看现有最大连接数

omm=# SHOW max_connections;
 max_connections 
-----------------
 200
(1 row)

omm=# SELECT count(*) FROM (SELECT pg_stat_get_backend_idset() AS backendid) AS s;
 count 
-------
    21
(1 row)

5、对表进行VACUUM、VACUUM FULL和ANALYZE操作

omm=# CREATE TABLE customer_t
omm-# (  c_customer_sk             integer,   
omm(# omm(#   c_customer_id             char(5),    
  c_first_name              char(6),    
  c_last_name               char(8) 
omm(# omm(# ) ;

ERROR:  relation "customer_t" already exists in schema "public"
DETAIL:  creating new table with existing name in the same schema
omm=# INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES    
omm-# (6885, 1, 'Joes', 'Hunter'),    
omm-# (4321, 2, 'Lily','Carter'),    
omm-# (9527, 3, 'James', 'Cook'),
omm-# (9500, 4, 'Lucy', 'Baker');
INSERT 0 4
omm=# select count(*) from customer_t;
 count 
-------
     8
(1 row)

omm=# 
omm=# 
omm=# VACUUM customer_t;
VACUUM
omm=# 
omm=# VACUUM FULL customer_t;
CREATE TABLESPACE EXAMPLE RELATIVE LOCATION 'tablespace1/tablespace_1';
CREATE schema HR;

CREATE TABLE HR.areaS(   area_ID NUMBER,   area_NAME VARCHAR2(25)  )tablespace EXAMPLE;
\d HR.areaS
CREATE INDEX areaS_idx ON HR.areaS (area_id);


REINDEX  table HR.areaS;
VACUUM
omm=# 
omm=# ANALYZE customer_t;
ANALYZE
omm=# 
omm=# ANALYZE VERBOSE customer_t;
INFO:  analyzing "public.customer_t"(gaussdb pid=1)
INFO:  ANALYZE INFO : "customer_t": scanned 1 of 1 pages, containing 8 live rows and 0 dead rows; 8 rows in sample, 8 estimated total rows(gaussdb pid=1)
ANALYZE
omm=# 
omm=# VACUUM ANALYZE customer_t;
VACUUM
omm=# 

6、建表、索引，进行重建索引操作

omm=# CREATE TABLESPACE EXAMPLE RELATIVE LOCATION 'tablespace1/tablespace_1';
CREATE schema HR;
CREATE TABLESPACE
omm=# CREATE SCHEMA
omm=# 
omm=# CREATE TABLE HR.areaS(   area_ID NUMBER,   area_NAME VARCHAR2(25)  )tablespace EXAMPLE;
CREATE TABLE
omm=# \d HR.areaS
               Table "hr.areas"
  Column   |         Type          | Modifiers 
-----------+-----------------------+-----------
 area_id   | numeric               | 
 area_name | character varying(25) | 
Tablespace: "example"

omm=# CREATE INDEX areaS_idx ON HR.areaS (area_id);
CREATE INDEX
omm=# 
omm=# 
REINDEX  table HR.areaS;
omm=# REINDEX