Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.2(EOL), 10.3(EOL), 10.4(EOL), 10.5, 10.6, 10.7(EOL)
Description
The following stack trace could cause reduced performance in cases when the speculative read-ahead is futile, and some useful pages are evicted as a result:
10.5 |
buf_LRU_get_free_block
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buf_page_init_for_read
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buf_read_page_low
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buf_read_page_background
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btr_cur_prefetch_siblings
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It could be more useful to only attempt read-ahead if a free block is available in the buffer pool without evicting any page that:
- is not marked as freed, or
- is not marked as dirty
Furthermore, we should probably avoid read-ahead altogether for temporary tables.
Attachments
Issue Links
- relates to
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MDEV-26782 InnoDB temporary tablespace: reclaiming of free space does not work
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- Closed
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origin/bb-10.11-
MDEV-30216-MDEV-26790c85c38683af18c5851afa5382aa7aaf869536176 2023-01-13T16:46:20+02:00performed well in RQG testing. Bad effects observed were in the main trees too.