Timeline for How does InnoDB access disk?
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 2, 2015 at 9:21 | history | migrated | from stackoverflow.com (revisions) | ||
| Feb 24, 2015 at 21:42 | comment | added | jeremycole | InnoDB only reads an extent at a time in read-ahead when it detects an linear scan. Most of the time it reads a page (16 KB with uncompressed tables) at a time. However the questioner is probably on a wrong premise, the OS is responsible for figuring out how to read the requested size read from the filesystem. MySQL/InnoDB requests 16 KB and doesn't care if the OS reads that from a single (large) page, 2 8 KB pages, 4 4 KB pages, etc... it has no control over that. | |
| Feb 17, 2015 at 20:20 | comment | added | Marcus Adams | According to MySQL documentation, it seems MySQL reads an extent (1MB) at a time from disk to the buffer pool, where it will access it a page at a time. | |
| Feb 17, 2015 at 20:08 | comment | added | spartacus | Hi Marcus, what I want to learn is if disk accesses are managed by file system how InnoDB make 16 Kb block i/o request to disk at a time? | |
| Feb 17, 2015 at 19:58 | history | answered | Marcus Adams | CC BY-SA 3.0 |