[MDEV-6664] Windows IOPS issue (slow read) Created: 2014-08-29 Updated: 2014-09-04 Resolved: 2014-09-04 |
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| Status: | Closed |
| Project: | MariaDB Server |
| Component/s: | None |
| Affects Version/s: | 10.0.13 |
| Fix Version/s: | N/A |
| Type: | Bug | Priority: | Major |
| Reporter: | Simone Giordano | Assignee: | Unassigned |
| Resolution: | Not a Bug | Votes: | 0 |
| Labels: | performance, windows | ||
| Environment: |
Windows 7 x64, SSD disk |
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| Attachments: |
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| Description |
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There is something strange on disk usage (IOPS) on Windows version. The test archive is a ledger table with 22.800.000 rows, each rows has 69 columns for a total row length of 832 bytes. On the same machine (i5 4 core, Samsung SSD 840) there is a big difference between SQL Server and MariaDB. Same query repeated a lot of times, takes about 30sec for a full table scan on SQL Server and about 90sec with MariaDB. 3x times! Watching filesystem activity with Performance Monitor, I've seen that SQL Server can reach 400/450 MB/sec reading its MDF file. I've tried with innodb_io_capacity parameter but without lucky. In attachment you find table structure and some screenshots. |
| Comments |
| Comment by Sergei Golubchik [ 2014-09-04 ] |
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It doesn't look like a bug so far. InnoDB internal file layout is different, may be it's not well as good optimized for full table scans, but works much better for point lookups or ranges. Either way, I don't think it's a bug. |