Preparation for pgq_coop: make sub_id non-unique.

To allow sharing retry events between coop consumers,
the simplest way is to make then share same sub_id.
So remove any assumptions from the code that
sub_id is unique.

This patch also fixes 2 long-standing bugs:
- pgq.retry_queue had double index
- pgq.subscription.batch_id did not had index

As both had only minor effect on performance, they went
unnoticed so long.

5 files changed, 25 insertions, 17 deletions

diff --git a/sql/pgq/functions/pgq.event_retry.sql b/sql/pgq/functions/pgq.event_retry.sql
index 5b349b43..ee54d3a1 100644
--- a/sql/pgq/functions/pgq.event_retry.sql
+++ b/sql/pgq/functions/pgq.event_retry.sql
@@ -17,10 +17,10 @@ returns integer as $$
 --     nothing
 -- ----------------------------------------------------------------------
 begin
-    insert into pgq.retry_queue (ev_retry_after,
+    insert into pgq.retry_queue (ev_retry_after, ev_queue,
         ev_id, ev_time, ev_txid, ev_owner, ev_retry, ev_type, ev_data,
         ev_extra1, ev_extra2, ev_extra3, ev_extra4)
-    select x_retry_time,
+    select x_retry_time, sub_queue,
            ev_id, ev_time, NULL, sub_id, coalesce(ev_retry, 0) + 1,
            ev_type, ev_data, ev_extra1, ev_extra2, ev_extra3, ev_extra4
       from pgq.get_batch_events(x_batch_id),
diff --git a/sql/pgq/functions/pgq.event_retry_raw.sql b/sql/pgq/functions/pgq.event_retry_raw.sql
index 3a2efb29..3a9bcd52 100644
--- a/sql/pgq/functions/pgq.event_retry_raw.sql
+++ b/sql/pgq/functions/pgq.event_retry_raw.sql
@@ -38,7 +38,7 @@ declare
     q record;
     id bigint;
 begin
-    select sub_id, queue_event_seq into q
+    select sub_id, queue_event_seq, sub_queue into q
       from pgq.consumer, pgq.queue, pgq.subscription
      where queue_name = x_queue
        and co_name = x_consumer
@@ -53,10 +53,11 @@ begin
         id := nextval(q.queue_event_seq);
     end if;
 
-    insert into pgq.retry_queue (ev_retry_after,
+    insert into pgq.retry_queue (ev_retry_after, ev_queue,
             ev_id, ev_time, ev_owner, ev_retry,
             ev_type, ev_data, ev_extra1, ev_extra2, ev_extra3, ev_extra4)
-    values (x_retry_after, x_ev_id, x_ev_time, q.sub_id, x_ev_retry,
+    values (x_retry_after, q.sub_queue,
+            x_ev_id, x_ev_time, q.sub_id, x_ev_retry,
             x_ev_type, x_ev_data, x_ev_extra1, x_ev_extra2,
             x_ev_extra3, x_ev_extra4);
 
diff --git a/sql/pgq/functions/pgq.maint_retry_events.sql b/sql/pgq/functions/pgq.maint_retry_events.sql
index 8e4bfa4b..64110db9 100644
--- a/sql/pgq/functions/pgq.maint_retry_events.sql
+++ b/sql/pgq/functions/pgq.maint_retry_events.sql
@@ -20,10 +20,9 @@ begin
         select queue_name,
                ev_id, ev_time, ev_owner, ev_retry, ev_type, ev_data,
                ev_extra1, ev_extra2, ev_extra3, ev_extra4
-          from pgq.retry_queue, pgq.queue, pgq.subscription
+          from pgq.retry_queue, pgq.queue
          where ev_retry_after <= current_timestamp
-           and sub_id = ev_owner
-           and queue_id = sub_queue
+           and queue_id = ev_queue
          order by ev_retry_after
          limit 10
     loop
diff --git a/sql/pgq/functions/pgq.unregister_consumer.sql b/sql/pgq/functions/pgq.unregister_consumer.sql
index c97261d6..9356bcec 100644
--- a/sql/pgq/functions/pgq.unregister_consumer.sql
+++ b/sql/pgq/functions/pgq.unregister_consumer.sql
@@ -18,6 +18,7 @@ returns integer as $$
 -- ----------------------------------------------------------------------
 declare
     x_sub_id integer;
+    _sub_id_cnt integer;
 begin
     select sub_id into x_sub_id
         from pgq.subscription, pgq.consumer, pgq.queue
@@ -29,6 +30,14 @@ begin
         raise exception 'consumer not registered on queue';
     end if;
 
+    -- subconsumer-aware
+    select count(*) into _sub_id_cnt
+        from pgq.subscription
+       where sub_id = x_sub_id;
+    if _sub_id_cnt > 1 then
+        raise exception 'unregistered subconsumers detected';
+    end if;
+
     delete from pgq.retry_queue
         where ev_owner = x_sub_id;
 
diff --git a/sql/pgq/structure/tables.sql b/sql/pgq/structure/tables.sql
index 43d27287..02d2f0a4 100644
--- a/sql/pgq/structure/tables.sql
+++ b/sql/pgq/structure/tables.sql
@@ -147,15 +147,14 @@ create table pgq.subscription (
         sub_batch                       bigint,
         sub_next_tick                   bigint,
 
-        constraint subscription_pkey primary key (sub_id),
-        constraint subscription_ukey unique (sub_queue, sub_consumer),
+        constraint subscription_pkey primary key (sub_queue, sub_consumer),
+        constraint subscription_batch_idx unique (sub_batch),
         constraint sub_queue_fkey foreign key (sub_queue)
                                    references pgq.queue (queue_id),
         constraint sub_consumer_fkey foreign key (sub_consumer)
                                    references pgq.consumer (co_id)
 );
 
-
 -- ----------------------------------------------------------------------
 -- Table: pgq.event_template
 --
@@ -198,21 +197,22 @@ create table pgq.event_template (
 --
 -- Columns:
 --      ev_retry_after          - time when it should be re-inserted to main queue
+--      ev_queue                - queue id, used to speed up event copy into queue
 --      *                       - same as pgq.event_template
 -- ----------------------------------------------------------------------
 create table pgq.retry_queue (
     ev_retry_after          timestamptz     not null,
+    ev_queue                int4            not null,
 
     like pgq.event_template,
 
     constraint rq_pkey primary key (ev_owner, ev_id),
-    constraint rq_owner_fkey foreign key (ev_owner)
-                             references pgq.subscription (sub_id)
+    constraint rq_queue_id_fkey foreign key (ev_queue)
+                             references pgq.queue (queue_id)
 );
 alter table pgq.retry_queue alter column ev_owner set not null;
 alter table pgq.retry_queue alter column ev_txid drop not null;
 create index rq_retry_idx on pgq.retry_queue (ev_retry_after);
-create index rq_retry_owner_idx on pgq.retry_queue (ev_owner, ev_id);
 
 -- ----------------------------------------------------------------------
 -- Table: pgq.failed_queue
@@ -222,6 +222,7 @@ create index rq_retry_owner_idx on pgq.retry_queue (ev_owner, ev_id);
 -- Columns:
 --      ev_failed_reason               - consumer's excuse for not processing
 --      ev_failed_time                 - when it was tagged failed
+--      ev_queue                       - queue id
 --      *                              - same as pgq.event_template
 -- ----------------------------------------------------------------------
 create table pgq.failed_queue (
@@ -231,9 +232,7 @@ create table pgq.failed_queue (
     -- all event fields
     like pgq.event_template,
 
-    constraint fq_pkey primary key (ev_owner, ev_id),
-    constraint fq_owner_fkey foreign key (ev_owner)
-                             references pgq.subscription (sub_id)
+    constraint fq_pkey primary key (ev_owner, ev_id)
 );
 alter table pgq.failed_queue alter column ev_owner set not null;
 alter table pgq.failed_queue alter column ev_txid drop not null;