MySQL Bugs: #3879: Automatic Lock is rising when using SELECT

Bug #3879	Automatic Lock is rising when using SELECT
Submitted:	25 May 2004 7:36	Modified:	29 May 2004 16:56
Reporter:	Sivan Narayana	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server	Severity:	S2 (Serious)
Version:	3.23..42	OS:	Linux (Linux 7.0)
Assigned to:		CPU Architecture:	Any

Description:
Right now we are generating some reports using one table.We are generating all type of reports successfully.We are using same table to generate all types reports.The problem is ..when we are accessing the table for one report..at the same if we try to display other report in new window..it is not even starting the process ..upto first report finished.

After completing the total process of the first report..second report is starting.Even the first report having 200 recors..and second one is having no records..second report is not starting the process.

We checked in SQL shell to see the total procesess are going in MySql.Only one SQL statement are in active mode..while the remaining all requests are in sleep mode..if we try to access the same table.

We are assuming..internally MySql is locking the table. 

How to repeat:
If there is anybody to help me..please send me a mail to sivalsm@yahoo.com

Suggested fix:
Now we had a another plan to fix this.We are dumping the total resultant data into a temporary table...then we are releasing the original table..so, other request (query) can take the access on original table.

Anyways..this should not be the case..we are thinking the correct solutions for this.

Bug 3720 Showed the same problem!

INNODB don't show this problem! Just Heap AND MyIsam!!!!

Thank you for writting to us.

What you describe is not a bug. MyISAM uses implicit table locks on all SELECT's in 3.23.*.

Workaround is to use 4.1 or to move to InnoDB.