| Bug #40634 | table scan temporary table is 4x slower due to mmap instead instead of caching | ||
|---|---|---|---|
| Submitted: | 11 Nov 2008 11:30 | Modified: | 23 Mar 2009 2:06 |
| Reporter: | Shane Bester (Platinum Quality Contributor) | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: MyISAM storage engine | Severity: | S5 (Performance) |
| Version: | 5.1.29, 6.0.x | OS: | Any |
| Assigned to: | Alexey Botchkov | CPU Architecture: | Any |
| Tags: | mmap, read_buffer_size, regression, table scan, temporary table | ||
If the data you need to attach is more than 50MB, you should create a compressed archive of the data, split it to 50MB chunks, and upload each of them as a separate attachment.
To split a large file:
- On *nix platforms use the split command e.g.
split -b 50MB <my_large_archive> <my_split_archive_prefix> - On windows use WinZip or a similar utility to split the large file
