Timeline for Substr() with Group by clause
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Sep 12, 2017 at 16:28 | comment | added | RDFozz | FYI - See latest question edit - multiple runs of OP's queries, alternating, with faster one first show this is not a cold vs hot data issue. | |
| Sep 11, 2017 at 18:30 | comment | added | Evan Carroll | @Harshil I showed you explicit that this is the problem. In the profile query 2 & 4 use substr. As you can see, 4 is slower than 3. | |
| Sep 10, 2017 at 16:21 | comment | added | Harshil | I found this problem in an contest on a website where to get actual runtime of query they are creating new table every time the query is executed by any user so that they can assign rank to users according to result and runtime of query. So i don't think that reason behind the lower runtime of query with substr() is caching of table. | |
| Sep 9, 2017 at 22:12 | history | edited | Evan Carroll | CC BY-SA 3.0 |
edited body
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| Sep 9, 2017 at 21:34 | history | edited | Evan Carroll | CC BY-SA 3.0 |
added 2926 characters in body
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| Sep 9, 2017 at 21:28 | history | answered | Evan Carroll | CC BY-SA 3.0 |