Display correct effective size #19094
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Signed-off-by: Maximilian Krög <maximilian.kroeg@geocept.com>
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## QA_5_2 #19094 +/- ##
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- Coverage 48.61% 47.41% -1.21%
Complexity 17028 17028
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Files 607 607
Lines 72365 72362 -3
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- Hits 35182 34310 -872
- Misses 37183 38052 +869
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| $showtable['Data_length'] | ||
| + $showtable['Index_length'] | ||
| - $showtable['Data_free'], | ||
| $showtable['Data_length'] + $showtable['Index_length'] + $showtable['Data_free'], |
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a 20+ years bug ?
Seems to have been added in 8448577#diff-83e3a89d98949a8b6e583e77d428adf8b1f0d8b54abba4afaa97728b5f7b8edbR275
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I still can not find a conclusion using external sources.
See: https://tableplus.com/blog/2018/04/mysql-get-size-of-tables.html or https://www.a2hosting.com/kb/developer-corner/mysql/determining-the-size-of-mysql-databases-and-tables/
Do you have an idea on how to verify the new total is the right one ?
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@williamdes not sure if is related or not, but I've encountered many times a strange issue like, the total size of a db or table had a different size after duplicating it from phpMyAdmin - (MyISAM engine).
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The effective size should match the .ibd file size.
The .ibd file for this table is 10.764.288 KB
From #18771 (comment) roughly matches the sum of Overhead and Total (3.8 + 6.6) * 1024 * 1024 = 10,905,190.4 KB
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@williamdes You could create a table and insert a lot of data. Repeatedly check that the effective size matches the file size on disk after deleting some of the data.
Fixes #18771
Totalis the space needed for index and data,Effectiveis the file size on disk, which includes'Data_free', so it should be added instead of subtracted.