Timeline for MySQL: delete...where..in( ) vs delete..from..join, and locked tables on delete with subselect
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
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| Jun 23, 2015 at 7:09 | comment | added | 0x89 | With the slight difference that the optimizer will produce an equivalent query. | |
| Jun 22, 2015 at 8:48 | comment | added | Masoud | yeah im just missing a reference to the outer table. But that is not the point. That's just a illustration of how it will be treated in optimizer. | |
| Jun 22, 2015 at 8:26 | comment | added | 0x89 | Okay, you missed my point. I think what you did not consider is that both VARIABLE_SUBSTITUTION and BUILDRESULTSUMMARY have a column named BUILDRESULTSUMMARY_ID, so it should be: 'delete from VARIABLE_SUBSTITUTION where EXISTS ( select BUILDRESULTSUMMARY_ID from BUILDRESULTSUMMARY where BUILDRESULTSUMMARY.BUILDRESULTSUMMARY_ID = VARIABLE_SUBSTITUTION.BUILDRESULTSUMMARY_ID AND BUILDRESULTSUMMARY.BUILD_KEY = "BAM-1");'. Then it makes sense, and both queries do the same. | |
| Jun 18, 2015 at 16:24 | history | edited | Masoud | CC BY-SA 3.0 |
added 43 characters in body
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| Jun 18, 2015 at 9:37 | history | answered | Masoud | CC BY-SA 3.0 |