Merge pull request #1632 from Kobzol/queries-update

Update documentation on how to remove an artifact from the database

Author: Kobzol

database/queries.md

@@ -6,53 +6,16 @@ This is important for situations where there is some compilation error for a sta
 with a stable release of the compiler. While this should be rare, it happens sometimes e.g. because
 of future incompatibility lints turning into errors.
 
-The set of queries below show an example of removing the measured data and errors for the `html5ever`
-benchmark for Rust `1.69` and `1.70`.
-```sql
--- Remove 1.69 and 1.70 html5ever data and errors
--- Delete errors
-DELETE FROM error
-WHERE aid IN (
-    SELECT id
-    FROM artifact
-    WHERE name IN ('1.69.0', '1.70.0') AND
-          type = 'release'
-);
-
--- Delete collection records. This will enable `bench_published` to re-run the benchmarks.
-DELETE FROM collector_progress
-WHERE aid IN (
-    SELECT id
-    FROM artifact
-    WHERE name IN ('1.69.0', '1.70.0') AND
-          type = 'release'
-) AND step IN ('html5ever');
-
--- Note that there probably won't be any results in pstat, since the benchmark did not compile.
--- But it's possible that some configurations of it have compiled before. To avoid skewing
--- the average, we should thus still delete.
-
--- Delete compile benchmark data
-DELETE FROM pstat
-WHERE aid IN (
-    SELECT id
-    FROM artifact
-    WHERE name IN ('1.69.0', '1.70.0') AND
-          type = 'release'
-);
+The benchmark should be fixed first, and then the DB should be altered (see below).
 
--- Delete runtime benchmark data
-DELETE FROM runtime_pstat
-WHERE aid IN (
-    SELECT id
-    FROM artifact
-    WHERE name IN ('1.69.0', '1.70.0') AND
-          type = 'release'
-);
-```
-
-After running these queries, the benchmark should be fixed so that it is compilable again, and then
-the version should be re-benchmarked:
-```bash
-$ cargo run --bin collector bench_published <version>
+The easiest solution is to simply completely remove the artifact from the DB. There are
+`ON DELETE CASCADE` clauses for `aid` (artifact ID) on tables that reference it, so it should be
+enough to just delete the artifact from the `artifact` table.
+The set of queries below show an example of removing the measured data and errors for Rust `1.69`
+and `1.70`:
+```sql
+DELETE FROM artifact
+WHERE name IN ('1.69.0', '1.70.0') AND
+      type = 'release';
 ```
+After executing this query, the server should automatically re-benchmark these artifacts again.