select * from pg_stat_activity; 4、查询数据库中各个用户名对应的数据库连接数 select usename, count(*) from pg_stat_activity group by usename; 二、赋权操作 1、为指定用户赋予指定表的select权限 GRANT SELECT ON table_name TO username; 2、修改数据库表所属的ownner alter table table_name owner...
1.查下超过10 s的查询语句 select*From pg_stat_activitywherequery_start<=now()- interval'10 sec'and state notin('idle') and pid<>pg_backend_pid() and query ilike'select%'order by query_start ; 2. 超过10s的查询会被干掉 selectpg_terminate_backend(pid) From pg_stat_activitywherequery_st...
From pg_stat_activity where query_start<=now()- interval'10 sec' and state not in ('idle') and pid<>pg_backend_pid() and query ilike 'select%' order by query_start ; 1. 2. 3. 4. 5. 6. 2. 超过10s的查询会被干掉 select pg_terminate_backend(pid) From pg_stat_activity where ...
With newer pgs it's rather wide (22 columns as I write this). And, it's not always obvious what all this means. So let's try to figure it out. Connected to databasedepeszwith usertestand got: $SELECT*FROMpg_stat_activity ; datid │ datname │ pid │ leader_pid │ usesysid │...
instr_unique_sql_count 调大该参数,以免出现“missing SQL statement, GUC instr_unique_sql_count is too small.”的提示。 2、启用慢SQL gs_guc reload -N all -I all -c "log_min_duration_statement=5s" gs_guc reload -N all -I all -c "track_stmt_stat_level='OFF,L0'" ...
与count(distinct)都是很常见的操作。...count(distinct colA)就是将colA中所有出现过的不同值取出来,相信只要接触过数据库的同学都能明白什么意思。...count(distinct colA)的操作也可以用group by的方式完成,具体代码如下: select count(dist...
=$SELECTcategory_id,object_id,date_trunc('hour',interaction_ts)ASts,SUM(interaction_count)FILTER(WHEREinteraction_type='a')ASa_count,SUM(interaction_count)FILTER(WHEREinteraction_type='b')ASb_countFROMinput_dataGROUPBY1,2,3; While talking about optimizations, one idea that came was to store ...
主机适配器添加有两种方式:1.在PCI子系统扫描挂载驱动时添加;2.手动方式添加。所有基于硬件PCI接口的主机适配器都采用第一种方式。添加主机适配器包括两个步骤: 1. 分别主机适配器数据结构scsi_host_alloc 2. 将主机适配器添加到系统scsi_add_host struct Scsi_Host *scsi_host_alloc(struct scsi_host_...
CustVendSumForPaym::countPaymFormats Method [AX 2012] CustVendSumForPaym::countPaymModes Method [AX 2012] CustVendSumForPaym::description Method [AX 2012] CustVendSumForPaym::main Method [AX 2012] CustVendSumForPaym::newLedgerJournalTrans Method [AX 2012] CustVendSumForPaymRemittance Class [...
1. 表的数据量很大,且很少被缓存,导致语句需要扫描的元组很多; 2. 表的数据量很大,在修改、删除数据时需要修改较多的元组; 3. 向表中插入的数据量很大; 4. 业务上需要检索出的数据量很多; 5. 频繁的数据修改,导致表中存在很多死元组(dead tuple),影响扫描性能; ...