chore: optimize enqueue scripts

Resolves #73

Resources/enqueue-instances.sql

@@ -1,10 +1,31 @@
--- Queue all known instances.
-insert into ms_queued_instance (instance_id)
-select id as instance_id
-from "instance"
-on conflict do nothing;
+/*
+ * === Very important note ===
+ * This script uses unlogged writes which are NOT fail-safe!
+ * Make sure to stop ModShark and Sharkey before executing.
+ * Your instance data is not at risk, but ModShark's queues could be corrupted.
+ *  
+ * Recommendation: increase checkpoint_segments to 32 or higher.
+ * See https://stackoverflow.com/a/52271138 for details.
+ *
+ * https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-DESC-SET-LOGGED-UNLOGGED 
+ * https://www.postgresql.org/docs/current/sql-set-constraints.html
+ */
+
+begin transaction;
+
+-- Queue all known instances.
+set constraints all deferred;
+    alter table ms_queued_instance set unlogged;
+        insert into ms_queued_instance (instance_id)
+        select id as instance_id
+        from "instance"
+        on conflict do nothing;
+    alter table ms_queued_instance set logged;
+set constraints all immediate;
 
 -- Reset flags to ensure new instances get processed.
 delete from ms_flagged_instance f
 using ms_queued_instance q
-where q.instance_id = f.instance_id;
+where q.instance_id = f.instance_id;
+
+commit;

Resources/enqueue-notes.sql

@@ -1,10 +1,31 @@
--- Queue all known notes.
-insert into ms_queued_note (note_id)
-select id as note_id
-from "note"
-on conflict do nothing;
+/*
+ * === Very important note ===
+ * This script uses unlogged writes which are NOT fail-safe!
+ * Make sure to stop ModShark and Sharkey before executing.
+ * Your instance data is not at risk, but ModShark's queues could be corrupted.
+ *  
+ * Recommendation: increase checkpoint_segments to 32 or higher.
+ * See https://stackoverflow.com/a/52271138 for details.
+ *
+ * https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-DESC-SET-LOGGED-UNLOGGED 
+ * https://www.postgresql.org/docs/current/sql-set-constraints.html
+ */
+
+begin transaction;
+
+-- Queue all known notes.
+set constraints all deferred;
+    alter table ms_queued_note set unlogged;
+        insert into ms_queued_note (note_id)
+        select id as note_id
+        from "note"
+        on conflict do nothing;
+    alter table ms_queued_note set logged;
+set constraints all immediate;
 
 -- Reset flags to ensure new notes get processed.
 delete from ms_flagged_note f
 using ms_queued_note q
-where q.note_id = f.note_id;
+where q.note_id = f.note_id;
+
+commit;

Resources/enqueue-users.sql

@@ -1,10 +1,31 @@
--- Queue all known users.
-insert into ms_queued_user (user_id)
-select id as user_id
-from "user"
-on conflict do nothing;
+/*
+ * === Very important note ===
+ * This script uses unlogged writes which are NOT fail-safe!
+ * Make sure to stop ModShark and Sharkey before executing.
+ * Your instance data is not at risk, but ModShark's queues could be corrupted.
+ *  
+ * Recommendation: increase checkpoint_segments to 32 or higher.
+ * See https://stackoverflow.com/a/52271138 for details.
+ *
+ * https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-DESC-SET-LOGGED-UNLOGGED 
+ * https://www.postgresql.org/docs/current/sql-set-constraints.html
+ */
+
+begin transaction;
+
+-- Queue all known users.
+set constraints all deferred;
+    alter table ms_queued_user set unlogged;
+        insert into ms_queued_user (user_id)
+        select id as user_id
+        from "user"
+        on conflict do nothing;
+    alter table ms_queued_user set logged;
+set constraints all immediate;
 
 -- Reset flags to ensure new users get processed.
 delete from ms_flagged_user f
 using ms_queued_user q
-where q.user_id = f.user_id;
+where q.user_id = f.user_id;
+
+commit;