1> select top 10 * from t_log_user_login_1 2> go 1. 2. 3. 4. 5. 6. 3.在命令行里执行php文件 进入文件所在目录下面在执行这个命令 /usr/local/php/bin/php indexnew.php indexnew.php 是执行的php文件名 4.定时程序相关命令 crontab -l 查看所有的定时任务 crontab -e
Here’s a quick query for checking on your 10 slowest queries. Always a good idea to peek in on these and see if there’s any easy fixes to make things work a little faster. SELECT (total_exec_time / 1000 / 60) as total_min, mean_exec_time as avg_ms, calls, query FROM pg_st...
typeId=1188双查询结果用法当我们需要在select后在外面在包一层select,代码如下 var getAll = db.Queryable<Order>() .Select(it => new Order { Id = * 2, Name = }) .MergeTable()//将上面的操作变成一个表 mergetable .GroupBy(it => )//对表mergetable进行分组 .Select(it =>new{ id= }).To...
这是某个客户的BOSS系统中的一个top sql,SQL代码如下: SELECT t1.seq AS sequence ,t1.TemplateID AS templateId ,t1.parameter...<= : 1; 非常简单的一个SQL,每执行一次要消耗非常高的buffer gets,见下图: 执行计划是全表扫描: ---...针对这种sql,可以借助index的hint一招搞定,但是有个要求就是,表上...
以下是一个示例查询,用于从名为"table_name"的表中检索最新的10条记录: SELECT * FROM table_name ORDER BY timestamp_column DESC LIMIT 10; 在这个查询中,"table_name"是要查询的表的名称,"timestamp_column"是包含时间戳的列的名称。通过将结果按照时间戳降序排序,并使用LIMIT 10限制结果集的大小,...
postgres=# create table toast(plain text, main text, external text, extended text); CREATE TABLE postgres=# select oid,reltoastrelid from pg_class where relname='toast'; oid | reltoastrelid ---+--- 821650 | 821653 (1 row) postgres=# select * from pg_toast.pg_toast_821650; chunk_id...
Your Postgres commands in one place. Learn how to use psql to list and create Postgres databases, show your tables, enter your Postgres terminal, and more.
SELECT Title, max("Days In Top 10")::int as MaxDaysInTop10 FROM read_parquet('s3://duckdb-md-dataset-121/netflix_daily_top_10.parquet') AS ("Days In Top 10" varchar, Title varchar, Type varchar) WHERE Type = 'TV Show' GROUP BY Title ORDER BY MaxDaysInTop10 DESC LIMIT 5; 分析...
Underlying problem is the same, order all the rows by the column userid and select the top 10. The default sort order is ascending order in postgres. You might wonder how does the plan change, it has to sort all of the data anyway to get the top 10/bottom 10 rows. The answer is ...
1. limit 限制查询数量,语法 LIMIT行数[OFFSET 偏移量],如果没有偏移量,默认从1开始 如: select * from t_xml_report limit 10 Offset 5 SQL Server用法:使用TOP关键字 ,例:select TOP 15 * from T_