From d491221e899db55d74a0eb34edc8c3d22362da61 Mon Sep 17 00:00:00 2001
From: Jens Reimann <ctron@dentrassi.de>
Date: Fri, 18 Oct 2024 10:54:52 +0200
Subject: [PATCH] fix: performance issue in update_deprecated_advisory

---
 migration/src/lib.rs                          |  2 ++
 .../update_deprecated_advisory.sql            | 13 +++++---
 ...m0000680_fix_update_deprecated_advisory.rs | 33 +++++++++++++++++++
 3 files changed, 43 insertions(+), 5 deletions(-)
 create mode 100644 migration/src/m0000680_fix_update_deprecated_advisory.rs

diff --git a/migration/src/lib.rs b/migration/src/lib.rs
index 7fe039b3..67120295 100644
--- a/migration/src/lib.rs
+++ b/migration/src/lib.rs
@@ -84,6 +84,7 @@ mod m0000640_create_product_status;
 mod m0000650_alter_advisory_tracking;
 mod m0000660_purl_id_indexes;
 mod m0000670_version_cmp;
+mod m0000680_fix_update_deprecated_advisory;
 
 pub struct Migrator;
 
@@ -175,6 +176,7 @@ impl MigratorTrait for Migrator {
             Box::new(m0000650_alter_advisory_tracking::Migration),
             Box::new(m0000660_purl_id_indexes::Migration),
             Box::new(m0000670_version_cmp::Migration),
+            Box::new(m0000680_fix_update_deprecated_advisory::Migration),
         ]
     }
 }
diff --git a/migration/src/m0000650_alter_advisory_tracking/update_deprecated_advisory.sql b/migration/src/m0000650_alter_advisory_tracking/update_deprecated_advisory.sql
index b3e84911..2817068b 100644
--- a/migration/src/m0000650_alter_advisory_tracking/update_deprecated_advisory.sql
+++ b/migration/src/m0000650_alter_advisory_tracking/update_deprecated_advisory.sql
@@ -2,12 +2,15 @@ CREATE OR REPLACE FUNCTION update_deprecated_advisory(identifier_input TEXT DEFA
     RETURNS VOID AS
 $$
 BEGIN
+    WITH MostRecent AS (SELECT DISTINCT ON (identifier) id
+                        FROM advisory
+                        WHERE identifier = COALESCE(identifier_input, identifier)
+                        ORDER BY identifier, modified DESC)
     UPDATE advisory
-    SET deprecated = (id != (SELECT id
-                             FROM advisory a
-                             WHERE a.identifier = COALESCE(identifier_input, advisory.identifier)
-                             ORDER BY a.modified DESC
-                             LIMIT 1))
+    SET deprecated = CASE
+                         WHEN id IN (SELECT id FROM MostRecent) THEN FALSE
+                         ELSE TRUE
+        END
     WHERE identifier = COALESCE(identifier_input, identifier);
 END;
 $$ LANGUAGE plpgsql;
diff --git a/migration/src/m0000680_fix_update_deprecated_advisory.rs b/migration/src/m0000680_fix_update_deprecated_advisory.rs
new file mode 100644
index 00000000..7331a9af
--- /dev/null
+++ b/migration/src/m0000680_fix_update_deprecated_advisory.rs
@@ -0,0 +1,33 @@
+use sea_orm_migration::prelude::*;
+
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        // This one is a bit special. The original migration was bugged by a performance issue. So
+        // we need to replace that function if it was already present and passed the migration. But
+        // We also need to replace the function in case the migration was not yet run. Because
+        // otherwise, the migration would not pass.
+        //
+        // The strategy is to replace the original function with the new content, and re-apply it
+        // with this migration. If the original migration did not yet pass, it would now. In any
+        // case, this migration ensures the new content of the function from now on.
+        manager
+            .get_connection()
+            .execute_unprepared(include_str!(
+                "m0000650_alter_advisory_tracking/update_deprecated_advisory.sql"
+            ))
+            .await
+            .map(|_| ())?;
+
+        Ok(())
+    }
+
+    async fn down(&self, _manager: &SchemaManager) -> Result<(), DbErr> {
+        // As the original version of this function was flawed, we replaced the original content
+        // and don't migrate back.
+        Ok(())
+    }
+}