internal/db: add cred store pagination schema changes

Add create time, update time columns to base table,
add indexes used by list queries.

internal/db/schema/migrations/oss/postgres/44/01_credentials.up.sql

@@ -16,6 +16,7 @@ begin;
   -- insert_credential_store_subtype() is a before insert trigger
   -- function for subtypes of credential_store.
   -- Replaces the insert_credential_store_subtype function defined in 10/03_credential.up.sql
+  -- Replaced in 80/05_credential_store_base_table_updates.up.sql
   create or replace function insert_credential_store_subtype() returns trigger
   as $$
   begin

internal/db/schema/migrations/oss/postgres/80/05_credential_store_base_table_updates.up.sql

@@ -0,0 +1,59 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: BUSL-1.1
+
+begin;
+
+  -- Add create_time and update_time to credential_store table.
+  alter table credential_store add column create_time wt_timestamp;
+  alter table credential_store add column update_time wt_timestamp;
+
+  -- Update rows with current values
+  update credential_store
+    set create_time = cvs.create_time, update_time = cvs.update_time
+    from credential_store as cl
+    left join credential_vault_store as cvs on cl.public_id = cvs.public_id;
+  update credential_store
+    set create_time = css.create_time, update_time = css.update_time
+    from credential_store as cl
+    left join credential_static_store as css on cl.public_id = css.public_id;
+
+  -- Replace the insert trigger to also set the create_time
+  -- Replaces the insert_credential_store_subtype function defined in 44/01_credentials.up.sql
+   create or replace function insert_credential_store_subtype() returns trigger
+  as $$
+  begin
+    insert into credential_store
+      (public_id, project_id, create_time)
+    values
+      (new.public_id, new.project_id, new.create_time);
+    return new;
+  end;
+  $$ language plpgsql;
+
+  -- Add trigger to update the new update_time column on every subtype update.
+  create function update_credential_store_table_update_time() returns trigger
+  as $$
+  begin
+    update credential_store set update_time = now() where public_id = new.public_id;
+    return new;
+  end;
+  $$ language plpgsql;
+  comment on function update_credential_store_table_update_time() is
+    'update_credential_store_table_update_time is used to automatically update the update_time '
+    'of the base table whenever one of the subtype tables are updated';
+
+  -- Add triggers to subtype tables
+  create trigger update_credential_store_table_update_time before update on credential_vault_store
+    for each row execute procedure update_credential_store_table_update_time();
+  create trigger update_credential_store_table_update_time before update on credential_static_store
+    for each row execute procedure update_credential_store_table_update_time();
+
+  -- Add new indexes for the create and update time queries.
+  create index credential_store_create_time_public_id_idx
+      on credential_store (create_time desc, public_id asc);
+  create index credential_store_update_time_public_id_idx
+      on credential_store (update_time desc, public_id asc);
+
+  analyze credential_store;
+
+commit;

internal/db/sqltest/tests/pagination/credential_store.sql

@@ -0,0 +1,32 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: BUSL-1.1
+
+begin;
+  select plan(9);
+
+  -- Verify the trigger functions exist and are declared properly
+  select has_function('update_credential_store_table_update_time');
+  select volatility_is('update_credential_store_table_update_time', 'volatile');
+  select isnt_strict('update_credential_store_table_update_time');
+  select has_trigger('credential_vault_store', 'update_credential_store_table_update_time');
+  select has_trigger('credential_static_store', 'update_credential_store_table_update_time');
+  select has_index('credential_store', 'credential_store_create_time_public_id_idx', array['create_time', 'public_id']);
+  select has_index('credential_store', 'credential_store_update_time_public_id_idx', array['update_time', 'public_id']);
+
+  -- To test that the trigger that sets the create_time of the base table
+  -- when an insert into a subtype table happens works, we check that the
+  -- create time of the entries in both tables match
+  prepare credential_store_create_time as select create_time from credential_store where public_id='cvs__bcolors';
+  prepare credential_vault_store_create_time as select create_time from credential_vault_store where public_id='cvs__bcolors';
+  select results_eq('credential_store_create_time','credential_vault_store_create_time');
+  -- To test the trigger that updates the update_time of the base table,
+  -- we update one of the existing creds and check that the base table
+  -- entry has the same update_time as the subtype one.
+  update credential_vault_store set name='blue black vault store' where public_id='cvs__bcolors';
+  prepare credential_store_update_time as select update_time from credential_store where public_id='cvs__bcolors';
+  prepare credential_vault_store_update_time as select update_time from credential_vault_store where public_id='cvs__bcolors';
+  select results_eq('credential_store_update_time','credential_vault_store_update_time');
+
+  select * from finish();
+
+rollback;