在Postgres(以及任何没有Oracle的数据库)中,NULL不是空字符串,空字符串也不是NULL。 因此,预计会出现此错误: postgres=# do $$ declare x int; begin perform set_config('x.xx', null, false); execute $_$ select current_setting('x.xx', true) $_$ into x; end; $$; ERROR: invalid input s...
SELECTname , settingFROMpg_settingswherename='XXX';SELECTcurrent_setting(name) ;show参数名|showall 4.使配置生效
selectversion(); 2.2 查看版本信息 showserver_version; 2.2 查看数字版本信息包括小版号 SHOWserver_version_num; 或 SELECTcurrent_setting('server_version_num'); 3.注意事项 SELECT current_setting(‘server_version_num’);返回类型为text,如果需要可以转换为interger SELECTcurrent_setting('server_version_num'...
current_setting(setting_nametext[,missing_okboolean] ) →text 返回设置的setting_name的当前值。 如果没有这样的设置,current_setting将抛出一个错误,除非missing_ok被提供并且为true。 这个函数对应于SQL命令SHOW。 current_setting('datestyle')→ISO, MDY set_config(setting_nametext,new_valuetext,is_localb...
SELECT schemaname, relname, n_live_tup, n_dead_tup, last_autovacuumFROM pg_stat_all_tablesORDER BY n_dead_tup / (n_live_tup * current_setting('autovacuum_vacuum_scale_factor')::float8 + current_setting('autovacuum_vacuum_threshold')::float8) DESCLIMIT 10; ...
show xxx;或select current_setting('xxx'); 3、修改参数 修改当前session的参数配置: set maintenance_work_mem to '128M';或select set_config('maintenance_work_mem','128M',false);ALTER SYSTEM动态修改全局参数: ALTER SYSTEM SET configuration_parameter { TO | = } { value | 'value' | DEFAULT ...
postgres=# select*fromcurrent_setting('port');current_setting---6000(1row) 3. 不使用默认postgres数据库 建议新建数据库后删除默认的postgres数据库 代码语言:javascript 代码运行次数:0 运行 AI代码解释 postgres=# create database my_app_db owner app1;CREATEDATABASEpostgres=# \c my_app_dbYou are ...
/* child node cost */ + 0.1 * current_setting('cpu_operator_cost')::real * reltuples * 0.01027850 ) FROM pg_class WHERE relname = 'idx_a_t1' ), ( SELECT round( cost_per_page * pages_fetched + current_setting('cpu_tuple_cost')::real * tuples_fetched...
(current_setting('autovacuum_analyze_threshold')::NUMERIC(12,4))+(current_setting('autovacuum_analyze_scale_factor')::NUMERIC(12,4))*reltuples AS 自动分析阈值, (current_setting('autovacuum_vacuum_threshold')::NUMERIC(12,4))+(current_setting('autovacuum_vacuum_scale_factor')::NUMERIC(12,4)...
xiaoming=# select reltuples, current_setting('cpu_tuple_cost') as cpu_tuple_cost, reltuples * current_setting('cpu_tuple_cost')::real AS cpu_cost from pg_class where relname='t1'; reltuples | cpu_tuple_cost | cpu_cost ---+---+--- 2e+06 | 0.01 | 20000 (1 row) total_cost...