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数据库字符集查看select datname,pg_encoding_to_char(encoding) as encoding from pg_database;建表时指定字符集CREATE TABLE customers ( id SERIAL PRIMARY KEY, name VARCHAR 阅读全文
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SELECT pg_size_pretty(pg_total_relation_size(c.oid)) AS total_size, pg_size_pretty(pg_indexes_size(c.oid)) AS index_size, pg_size_pretty(pg_total_rela 阅读全文
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原始sql 执行半小时， 临时表gl_tmp1里大概2万条数据 select distinct ( gl_detail.pk_voucher ) from gl_detail , gl_contrast where gl_detail.pk_detail = gl_contrast.fk_detai 阅读全文
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select * from pg_indexes where tablename = 'table_name'; 阅读全文
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1，查看连接到某个数据库的连接select * from master.dbo.sysprocesses where dbid = DB_ID('NCCDB')*查询某个数据库用户的连接情况sp_who 'sa'2，查看数据库允许的最大连接select @@MAX_CONNECTIONS3，查看数据 阅读全文
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--改名EXEC sp_rename 'old_table_name', 'new_table_name';--备份select * into dbo.t_scs_0304 from dbo.t_scs; 对表结构字段进行修改： 添加列：alter table 表名 add 列名 varchar(5 阅读全文
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SQL> select para_name,para_value from v$dm_ini where para_name='ENABLE_RQ_TO_NONREF_SPL'; LINEID PARA_NAME PARA_VALUE 1 ENABLE_RQ_TO_NONREF_SPL 0 SQL> 阅读全文
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关机重启数据时遇到报错如下： SQL> alter database open;alter database open*ERROR at line 1:ORA-01092: ORACLE instance terminated. Disconnection forcedORA-00704: boot 阅读全文
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从库 对表做truncate 时报1209 - The MySQL server is running with the--read-only option so it cannot execute this statement 处理： select @@read_only; set global 阅读全文
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查看统计信息 SELECT object_id , OBJECT_NAME(object_id) AS TableName , name AS StatisticsName , auto_created FROM sys.stats where objectproperty(object_id,'I 阅读全文