Timeline for Is there any performance difference between UNIQUE INDEX and INDEX with the same cardinality on MySQL?
Current License: CC BY-SA 4.0
3 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 2, 2023 at 21:54 | comment | added | Krusty the Clown |
Approaching it from a purely empirical perspective in Postgres, I noticed that when I (accidentally) created an index on the columns that were already my primary key (same columns, same order), Postgres actually gave a slightly higher cost without the extra index (through EXPLAIN). Of course, that is just one database, plus the cost difference was less than a percent.
|
|
| Jun 17, 2020 at 22:55 | vote | accept | Player1 | ||
| Jun 16, 2020 at 23:35 | history | answered | David Spillett | CC BY-SA 4.0 |