最近常常碰到网站慢的情况，登陆到后台，查询一下 /opt/ mysql /bin/ mysql admin processlist;发现一个查询状态为： Copy ing to tmp table 而且此查询速度非常慢，基本一分钟左右才出来，后面是很多查询，状态为lock。. MySQL will need to create temporary tables under certain circumstances e.g.

Given we did not know how long it will take we decided to kill the query in MySQL using kill. SQL Cloning Tables. The name of a temporary table must start with a hash (#). The DB software I'm using is PgAdmin III. SELECT * INTO OUTFILE 'my_table.csv' ..... 2. create table my_table_copy like my_table 3. drop all indexes (except primary key) on my_table_copy

Open 3 clients. : Sorting operations e.g. Calculate the progress by checking the size of temporary tablespace. Hi list, An others question, I am working on projet and i made some test.

Table will automatically be fixed on the receiving server if aria_chk --zerofill was not run. The final choice may be that using the real table rather than temporary table. if a query contains an "ORDER BY" clause, or "GROUP BY" clause. I am running MySql on a dual Xeon system running Windows 2000 server with 10 10K rpm drives in 5 raid 0 arrays and plenty of ram that isn't being utilized.

Copying to tmp table is a common thread state within MySQL which occurs when the MySQL server is copying to a temporary table in memory. If it says "Copy to temporary table" then it is an in-memory copy. This mysql query is extremely slow, when I look at the query it is "copying to tmp table". After creating the table the script uses the INSERT INTO command to populate #tmp_employees with the last_name, first_name, hire_date and job_title of all employees from the physical employee table who have a hire_date less than 1/1/2010.. Again, you can query the data using the same select statement provided above. copying to tmp table. We asked Phil for advice, thinking that it would be a simple explanation.

copy to tmp table的SQL语句，这条语读的时间比较长，且这个表会被加读锁，相关表的update语句会被排进队列。如果多执行几次这样的copyt to tmp table 语句，会造成更多的语句被阻塞。 If it says "Copy to temporary table on disk" then it has exceeded the size for in-memory temp tables and is dumping to disk. In the event of the latter than it will be … The first number following INSERT is the OID (object identifier) of the freshly inserted row. mysql Copy ing to tmp table on disk 影响性能的解决方法. Hope this helps.

A TempDB table is not dropped when you set its record buffer variable to null. Temporary tables are used by every DB developer, but they're not likely to be too adventurous with their use, or exploit all their advantages.

TempDB tables are a different type of temporary table than InMemory tables.

This affects InnoDB plugin, for example. To define a temporary table, we use the INTO statement after the SELECT statement. The SQL statement in Example 4-16 inserts a new book with an id of 41472, a title of Practical PostgreSQL, an author identifier of 1212, and a subject identifier of 4. Cloning or Copying a Table. We had an ALTER TABLE statement that added a new column which was taking quite a long time on status . I use large databases, some table go up to 1.8g. All types of temporary tables are automatically dropped by the system when the table variable in X++ goes out of scope. In this tutorial you will learn how to create a duplicate copy of an existing table. After creating the table the script uses the INSERT INTO command to populate #tmp_employees with the last_name, first_name, hire_date and job_title of all employees from the physical employee table who have a hire_date less than 1/1/2010.. Again, you can query the data using the same select statement provided above. 1. It depends what kind of temporary table. If the query contains "distinct". Maybe the copy-to-temp-table logic goes brain-dead around those significant sizes. Third, import the db.sql file to the database server with the assumption that the db.sql file was copied to c:\tmp\ folder. How to repeat: Use InnoDB plugin. With innodb_file_per_table=1,when we are running ALTER TABLE, InnoDB creates a temporary tablespace within the same data directory with random name starting from #sql ending with .ibd like #sql-1c80_27.ibd. (innodb_file_per_table is ON by default in MySQL 5.6.) The problem we have is wend I try to select data in table whit a group by function and I got " Copy to tmp table " This function take a long time to execute.

Some notice: Don't close the SQL connection session when the temporary table created. i.e A few things to note: The temp table is created in-memory (not on disk) I'd like to see if this can be improved without re-writing the … There may be a situation when you just want to create an exact copy or clone of an existing table to test or perform something without affecting the original table. As mentioned previously, these types of temp tables are … You will see your temporary table name along with the identifier.