Bug #62677 I don't understand the docs for innodb_random_read_ahead
Submitted: 11 Oct 2011 2:09 Modified: 30 Nov 2011 16:55
Reporter: Mark Callaghan Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:5.6.3 OS:Any
Assigned to: John Russell CPU Architecture:Any

[11 Oct 2011 2:09] Mark Callaghan 
Description:
In http://dev.mysql.com/doc/refman/5.6/en/innodb-performance.html the section on "13.2.5.2.14. Changes in the Read-Ahead Algorithm" states

>> If 64 consecutive pages from the same extent are found in the buffer pool, InnoDB 
>> synchronously issues a request to prefetch the remaining pages of the extent

If 64 pages from the extent are in the buffer pool, how many are not in the buffer pool.

How to repeat:
read the docs

Suggested fix:
I think the number that triggers it is less than 64
[11 Oct 2011 3:56] Valeriy Kravchuk 
Thank you for the bug report.
[30 Nov 2011 16:55] John Russell 
Corrected threshhold value to 13. This was the original hardcoded value used 
previously, and was unchanged when the feature was resurrected.