diff --git a/schema/pgsql/schema.sql b/schema/pgsql/schema.sql
index 16518e490..211bfd72f 100644
--- a/schema/pgsql/schema.sql
+++ b/schema/pgsql/schema.sql
@@ -43,7 +43,7 @@ CREATE TABLE available_channel_type (
 CREATE TABLE channel (
     id bigserial,
     name citext NOT NULL,
-    type text NOT NULL REFERENCES available_channel_type(type), -- 'email', 'sms', ...
+    type text NOT NULL, -- 'email', 'sms', ...
     config text, -- JSON with channel-specific attributes
     -- for now type determines the implementation, in the future, this will need a reference to a concrete
     -- implementation to allow multiple implementations of a sms channel for example, probably even user-provided ones
@@ -51,7 +51,8 @@ CREATE TABLE channel (
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
-    CONSTRAINT pk_channel PRIMARY KEY (id)
+    CONSTRAINT pk_channel PRIMARY KEY (id),
+    CONSTRAINT fk_channel_available_channel_type FOREIGN KEY (type) REFERENCES available_channel_type(type)
 );
 
 CREATE INDEX idx_channel_changed_at ON channel(changed_at);
@@ -60,7 +61,7 @@ CREATE TABLE contact (
     id bigserial,
     full_name citext NOT NULL,
     username citext, -- reference to web user
-    default_channel_id bigint NOT NULL REFERENCES channel(id),
+    default_channel_id bigint NOT NULL,
 
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
@@ -68,21 +69,24 @@ CREATE TABLE contact (
     CONSTRAINT pk_contact PRIMARY KEY (id),
 
     -- As the username is unique, it must be NULLed for deletion via "deleted = 'y'"
-    UNIQUE (username)
+    CONSTRAINT uk_contact_username UNIQUE (username),
+
+    CONSTRAINT fk_contact_channel FOREIGN KEY (default_channel_id) REFERENCES channel(id)
 );
 
 CREATE INDEX idx_contact_changed_at ON contact(changed_at);
 
 CREATE TABLE contact_address (
     id bigserial,
-    contact_id bigint NOT NULL REFERENCES contact(id),
+    contact_id bigint NOT NULL,
     type text NOT NULL, -- 'phone', 'email', ...
     address text NOT NULL, -- phone number, email address, ...
 
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
-    CONSTRAINT pk_contact_address PRIMARY KEY (id)
+    CONSTRAINT pk_contact_address PRIMARY KEY (id),
+    CONSTRAINT fk_contact_address_contact FOREIGN KEY (contact_id) REFERENCES contact(id)
 );
 
 CREATE INDEX idx_contact_address_changed_at ON contact_address(changed_at);
@@ -100,13 +104,15 @@ CREATE TABLE contactgroup (
 CREATE INDEX idx_contactgroup_changed_at ON contactgroup(changed_at);
 
 CREATE TABLE contactgroup_member (
-    contactgroup_id bigint NOT NULL REFERENCES contactgroup(id),
-    contact_id bigint NOT NULL REFERENCES contact(id),
+    contactgroup_id bigint NOT NULL,
+    contact_id bigint NOT NULL,
 
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
-    CONSTRAINT pk_contactgroup_member PRIMARY KEY (contactgroup_id, contact_id)
+    CONSTRAINT pk_contactgroup_member PRIMARY KEY (contactgroup_id, contact_id),
+    CONSTRAINT fk_contactgroup_member_contactgroup FOREIGN KEY (contactgroup_id) REFERENCES contactgroup(id),
+    CONSTRAINT fk_contactgroup_member_contact FOREIGN KEY (contact_id) REFERENCES contact(id)
 );
 
 CREATE INDEX idx_contactgroup_member_changed_at ON contactgroup_member(changed_at);
@@ -125,7 +131,7 @@ CREATE INDEX idx_schedule_changed_at ON schedule(changed_at);
 
 CREATE TABLE rotation (
     id bigserial,
-    schedule_id bigint NOT NULL REFERENCES schedule(id),
+    schedule_id bigint NOT NULL,
     -- the lower the more important, starting at 0, avoids the need to re-index upon addition
     priority integer,
     name text NOT NULL,
@@ -146,33 +152,36 @@ CREATE TABLE rotation (
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
+    CONSTRAINT pk_rotation PRIMARY KEY (id),
+
     -- Each schedule can only have one rotation with a given priority starting at a given date.
     -- Columns schedule_id, priority, first_handoff must be NULLed for deletion via "deleted = 'y'".
-    UNIQUE (schedule_id, priority, first_handoff),
-    CHECK (deleted = 'y' OR priority IS NOT NULL AND first_handoff IS NOT NULL),
+    CONSTRAINT uk_rotation_schedule_schedule_priority_first_handoff UNIQUE (schedule_id, priority, first_handoff),
+    CONSTRAINT ck_rotation_deleted_priority_first_handoff CHECK (deleted = 'y' OR priority IS NOT NULL AND first_handoff IS NOT NULL),
 
-    CONSTRAINT pk_rotation PRIMARY KEY (id)
+    CONSTRAINT fk_rotation_schedule FOREIGN KEY (schedule_id) REFERENCES schedule(id)
 );
 
 CREATE INDEX idx_rotation_changed_at ON rotation(changed_at);
 
 CREATE TABLE timeperiod (
     id bigserial,
-    owned_by_rotation_id bigint REFERENCES rotation(id), -- nullable for future standalone timeperiods
+    owned_by_rotation_id bigint, -- nullable for future standalone timeperiods
 
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
-    CONSTRAINT pk_timeperiod PRIMARY KEY (id)
+    CONSTRAINT pk_timeperiod PRIMARY KEY (id),
+    CONSTRAINT fk_timeperiod_rotation FOREIGN KEY (owned_by_rotation_id) REFERENCES rotation(id)
 );
 
 CREATE INDEX idx_timeperiod_changed_at ON timeperiod(changed_at);
 
 CREATE TABLE rotation_member (
     id bigserial,
-    rotation_id bigint NOT NULL REFERENCES rotation(id),
-    contact_id bigint REFERENCES contact(id),
-    contactgroup_id bigint REFERENCES contactgroup(id),
+    rotation_id bigint NOT NULL,
+    contact_id bigint,
+    contactgroup_id bigint,
     position integer,
 
     changed_at bigint NOT NULL,
@@ -180,27 +189,30 @@ CREATE TABLE rotation_member (
 
     -- Each position in a rotation can only be used once.
     -- Column position must be NULLed for deletion via "deleted = 'y'".
-    UNIQUE (rotation_id, position),
+    CONSTRAINT uk_rotation_member_rotation_position UNIQUE (rotation_id, position),
 
     -- Two UNIQUE constraints prevent duplicate memberships of the same contact or contactgroup in a single rotation.
     -- Multiple NULLs are not considered to be duplicates, so rows with a contact_id but no contactgroup_id are
     -- basically ignored in the UNIQUE constraint over contactgroup_id and vice versa. The CHECK constraint below
     -- ensures that each row has only non-NULL values in one of these constraints.
-    UNIQUE (rotation_id, contact_id),
-    UNIQUE (rotation_id, contactgroup_id),
+    CONSTRAINT uk_rotation_member_rotation_contact UNIQUE (rotation_id, contact_id),
+    CONSTRAINT uk_rotation_member_rotation_contactgroup UNIQUE (rotation_id, contactgroup_id),
 
     CONSTRAINT ck_rotation_member_either_contact_id_or_contactgroup_id CHECK (num_nonnulls(contact_id, contactgroup_id) = 1),
     CONSTRAINT ck_rotation_member_non_deleted_needs_position CHECK (deleted = 'y' OR position IS NOT NULL),
 
-    CONSTRAINT pk_rotation_member PRIMARY KEY (id)
+    CONSTRAINT pk_rotation_member PRIMARY KEY (id),
+    CONSTRAINT fk_rotation_member_rotation FOREIGN KEY (rotation_id) REFERENCES rotation(id),
+    CONSTRAINT fk_rotation_member_contact FOREIGN KEY (contact_id) REFERENCES contact(id),
+    CONSTRAINT fk_rotation_member_contactgroup FOREIGN KEY (contactgroup_id) REFERENCES contactgroup(id)
 );
 
 CREATE INDEX idx_rotation_member_changed_at ON rotation_member(changed_at);
 
 CREATE TABLE timeperiod_entry (
     id bigserial,
-    timeperiod_id bigint NOT NULL REFERENCES timeperiod(id),
-    rotation_member_id bigint REFERENCES rotation_member(id), -- nullable for future standalone timeperiods
+    timeperiod_id bigint NOT NULL,
+    rotation_member_id bigint, -- nullable for future standalone timeperiods
     start_time bigint NOT NULL,
     end_time bigint NOT NULL,
     -- Is needed by icinga-notifications-web to prefilter entries, which matches until this time and should be ignored by the daemon.
@@ -211,7 +223,9 @@ CREATE TABLE timeperiod_entry (
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
-    CONSTRAINT pk_timeperiod_entry PRIMARY KEY (id)
+    CONSTRAINT pk_timeperiod_entry PRIMARY KEY (id),
+    CONSTRAINT fk_timeperiod_entry_timeperiod FOREIGN KEY (timeperiod_id) REFERENCES timeperiod(id),
+    CONSTRAINT fk_timeperiod_entry_rotation_member FOREIGN KEY (rotation_member_id) REFERENCES rotation_member(id)
 );
 
 CREATE INDEX idx_timeperiod_entry_changed_at ON timeperiod_entry(changed_at);
@@ -247,8 +261,8 @@ CREATE TABLE source (
     -- The hash is a PHP password_hash with PASSWORD_DEFAULT algorithm, defaulting to bcrypt. This check roughly ensures
     -- that listener_password_hash can only be populated with bcrypt hashes.
     -- https://icinga.com/docs/icinga-web/latest/doc/20-Advanced-Topics/#manual-user-creation-for-database-authentication-backend
-    CHECK (listener_password_hash IS NULL OR listener_password_hash LIKE '$2y$%'),
-    CHECK (type != 'icinga2' OR (icinga2_base_url IS NOT NULL AND icinga2_auth_user IS NOT NULL AND icinga2_auth_pass IS NOT NULL)),
+    CONSTRAINT ck_bcrypt_source_listener_password_hash CHECK (listener_password_hash IS NULL OR listener_password_hash LIKE '$2y$%'),
+    CONSTRAINT ck_source_icinga2_has_config CHECK (type != 'icinga2' OR (icinga2_base_url IS NOT NULL AND icinga2_auth_user IS NOT NULL AND icinga2_auth_pass IS NOT NULL)),
 
     CONSTRAINT pk_source PRIMARY KEY (id)
 );
@@ -257,32 +271,34 @@ CREATE INDEX idx_source_changed_at ON source(changed_at);
 
 CREATE TABLE object (
     id bytea NOT NULL, -- SHA256 of identifying tags and the source.id
-    source_id bigint NOT NULL REFERENCES source(id),
+    source_id bigint NOT NULL,
     name text NOT NULL,
 
     url text,
     -- mute_reason indicates whether an object is currently muted by its source, and its non-zero value is mapped to true.
     mute_reason text,
 
-    CHECK (length(id) = 256/8),
-
-    CONSTRAINT pk_object PRIMARY KEY (id)
+    CONSTRAINT pk_object PRIMARY KEY (id),
+    CONSTRAINT ck_object_id_is_sha256 CHECK (length(id) = 256/8),
+    CONSTRAINT fk_object_source FOREIGN KEY (source_id) REFERENCES source(id)
 );
 
 CREATE TABLE object_id_tag (
-    object_id bytea NOT NULL REFERENCES object(id),
+    object_id bytea NOT NULL,
     tag text NOT NULL,
     value text NOT NULL,
 
-    CONSTRAINT pk_object_id_tag PRIMARY KEY (object_id, tag)
+    CONSTRAINT pk_object_id_tag PRIMARY KEY (object_id, tag),
+    CONSTRAINT fk_object_id_tag_object FOREIGN KEY (object_id) REFERENCES object(id)
 );
 
 CREATE TABLE object_extra_tag (
-    object_id bytea NOT NULL REFERENCES object(id),
+    object_id bytea NOT NULL,
     tag text NOT NULL,
     value text NOT NULL,
 
-    CONSTRAINT pk_object_extra_tag PRIMARY KEY (object_id, tag)
+    CONSTRAINT pk_object_extra_tag PRIMARY KEY (object_id, tag),
+    CONSTRAINT fk_object_extra_tag_object FOREIGN KEY (object_id) REFERENCES object(id)
 );
 
 CREATE TYPE event_type AS ENUM (
@@ -304,7 +320,7 @@ CREATE TYPE severity AS ENUM ('ok', 'debug', 'info', 'notice', 'warning', 'err',
 CREATE TABLE event (
     id bigserial,
     time bigint NOT NULL,
-    object_id bytea NOT NULL REFERENCES object(id),
+    object_id bytea NOT NULL,
     type event_type NOT NULL,
     severity severity,
     message text,
@@ -312,30 +328,32 @@ CREATE TABLE event (
     mute boolenum,
     mute_reason text,
 
-    CONSTRAINT pk_event PRIMARY KEY (id)
+    CONSTRAINT pk_event PRIMARY KEY (id),
+    CONSTRAINT fk_event_object FOREIGN KEY (object_id) REFERENCES object(id)
 );
 
 CREATE TABLE rule (
     id bigserial,
     name citext NOT NULL,
-    timeperiod_id bigint REFERENCES timeperiod(id),
+    timeperiod_id bigint,
     object_filter text,
 
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
-    CONSTRAINT pk_rule PRIMARY KEY (id)
+    CONSTRAINT pk_rule PRIMARY KEY (id),
+    CONSTRAINT fk_rule_timeperiod FOREIGN KEY (timeperiod_id) REFERENCES timeperiod(id)
 );
 
 CREATE INDEX idx_rule_changed_at ON rule(changed_at);
 
 CREATE TABLE rule_escalation (
     id bigserial,
-    rule_id bigint NOT NULL REFERENCES rule(id),
+    rule_id bigint NOT NULL,
     position integer,
     condition text,
     name citext, -- if not set, recipients are used as a fallback for display purposes
-    fallback_for bigint REFERENCES rule_escalation(id),
+    fallback_for bigint,
 
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
@@ -344,89 +362,106 @@ CREATE TABLE rule_escalation (
 
     -- Each position in an escalation can only be used once.
     -- Column position must be NULLed for deletion via "deleted = 'y'"
-    UNIQUE (rule_id, position),
+    CONSTRAINT uk_rule_escalation_rule_position UNIQUE (rule_id, position),
 
     CONSTRAINT ck_rule_escalation_not_both_condition_and_fallback_for CHECK (NOT (condition IS NOT NULL AND fallback_for IS NOT NULL)),
-    CONSTRAINT ck_rule_escalation_non_deleted_needs_position CHECK (deleted = 'y' OR position IS NOT NULL)
+    CONSTRAINT ck_rule_escalation_non_deleted_needs_position CHECK (deleted = 'y' OR position IS NOT NULL),
+    CONSTRAINT fk_rule_escalation_rule FOREIGN KEY (rule_id) REFERENCES rule(id),
+    CONSTRAINT fk_rule_escalation_rule_escalation FOREIGN KEY (fallback_for) REFERENCES rule_escalation(id)
 );
 
 CREATE INDEX idx_rule_escalation_changed_at ON rule_escalation(changed_at);
 
 CREATE TABLE rule_escalation_recipient (
     id bigserial,
-    rule_escalation_id bigint NOT NULL REFERENCES rule_escalation(id),
-    contact_id bigint REFERENCES contact(id),
-    contactgroup_id bigint REFERENCES contactgroup(id),
-    schedule_id bigint REFERENCES schedule(id),
-    channel_id bigint REFERENCES channel(id),
+    rule_escalation_id bigint NOT NULL,
+    contact_id bigint,
+    contactgroup_id bigint,
+    schedule_id bigint,
+    channel_id bigint,
 
     changed_at bigint NOT NULL,
     deleted boolenum NOT NULL DEFAULT 'n',
 
     CONSTRAINT pk_rule_escalation_recipient PRIMARY KEY (id),
-
-    CHECK (num_nonnulls(contact_id, contactgroup_id, schedule_id) = 1)
+    CONSTRAINT ck_rule_escalation_recipient_one_recipient CHECK (num_nonnulls(contact_id, contactgroup_id, schedule_id) = 1),
+    CONSTRAINT fk_rule_escalation_recipient_rule_escalation FOREIGN KEY (rule_escalation_id) REFERENCES rule_escalation(id),
+    CONSTRAINT fk_rule_escalation_recipient_contact FOREIGN KEY (contact_id) REFERENCES contact(id),
+    CONSTRAINT fk_rule_escalation_recipient_contactgroup FOREIGN KEY (contactgroup_id) REFERENCES contactgroup(id),
+    CONSTRAINT fk_rule_escalation_recipient_schedule FOREIGN KEY (schedule_id) REFERENCES schedule(id),
+    CONSTRAINT fk_rule_escalation_recipient_channel FOREIGN KEY (channel_id) REFERENCES channel(id)
 );
 
 CREATE INDEX idx_rule_escalation_recipient_changed_at ON rule_escalation_recipient(changed_at);
 
 CREATE TABLE incident (
     id bigserial,
-    object_id bytea NOT NULL REFERENCES object(id),
+    object_id bytea NOT NULL,
     started_at bigint NOT NULL,
     recovered_at bigint,
     severity severity NOT NULL,
 
-    CONSTRAINT pk_incident PRIMARY KEY (id)
+    CONSTRAINT pk_incident PRIMARY KEY (id),
+    CONSTRAINT fk_incident_object FOREIGN KEY (object_id) REFERENCES object(id)
 );
 
 CREATE TABLE incident_event (
-    incident_id bigint NOT NULL REFERENCES incident(id),
-    event_id bigint NOT NULL REFERENCES event(id),
+    incident_id bigint NOT NULL,
+    event_id bigint NOT NULL,
 
-    CONSTRAINT pk_incident_event PRIMARY KEY (incident_id, event_id)
+    CONSTRAINT pk_incident_event PRIMARY KEY (incident_id, event_id),
+    CONSTRAINT fk_incident_event_incident FOREIGN KEY (incident_id) REFERENCES incident(id),
+    CONSTRAINT fk_incident_event_event FOREIGN KEY (event_id) REFERENCES event(id)
 );
 
 CREATE TYPE incident_contact_role AS ENUM ('recipient', 'subscriber', 'manager');
 
 CREATE TABLE incident_contact (
-    incident_id bigint NOT NULL REFERENCES incident(id),
-    contact_id bigint REFERENCES contact(id),
-    contactgroup_id bigint REFERENCES contactgroup(id),
-    schedule_id bigint REFERENCES schedule(id),
+    incident_id bigint NOT NULL,
+    contact_id bigint,
+    contactgroup_id bigint,
+    schedule_id bigint,
     role incident_contact_role NOT NULL,
 
-    CONSTRAINT key_incident_contact_contact UNIQUE (incident_id, contact_id),
-    CONSTRAINT key_incident_contact_contactgroup UNIQUE (incident_id, contactgroup_id),
-    CONSTRAINT key_incident_contact_schedule UNIQUE (incident_id, schedule_id),
-    CONSTRAINT nonnulls_incident_recipients_check CHECK (num_nonnulls(contact_id, contactgroup_id, schedule_id) = 1)
+    CONSTRAINT uk_incident_contact_contact UNIQUE (incident_id, contact_id),
+    CONSTRAINT uk_incident_contact_contactgroup UNIQUE (incident_id, contactgroup_id),
+    CONSTRAINT uk_incident_contact_schedule UNIQUE (incident_id, schedule_id),
+    CONSTRAINT ck_incident_contact_one_recipient CHECK (num_nonnulls(contact_id, contactgroup_id, schedule_id) = 1),
+    CONSTRAINT fk_incident_contact_incident FOREIGN KEY (incident_id) REFERENCES incident(id),
+    CONSTRAINT fk_incident_contact_contact FOREIGN KEY (contact_id) REFERENCES contact(id),
+    CONSTRAINT fk_incident_contact_contactgroup FOREIGN KEY (contactgroup_id) REFERENCES contactgroup(id),
+    CONSTRAINT fk_incident_contact_schedule FOREIGN KEY (schedule_id) REFERENCES schedule(id)
 );
 
 CREATE TABLE incident_rule (
-    incident_id bigint NOT NULL REFERENCES incident(id),
-    rule_id bigint NOT NULL REFERENCES rule(id),
+    incident_id bigint NOT NULL,
+    rule_id bigint NOT NULL,
 
-    CONSTRAINT pk_incident_rule PRIMARY KEY (incident_id, rule_id)
+    CONSTRAINT pk_incident_rule PRIMARY KEY (incident_id, rule_id),
+    CONSTRAINT fk_incident_rule_incident FOREIGN KEY (incident_id) REFERENCES incident(id),
+    CONSTRAINT fk_incident_rule_rule FOREIGN KEY (rule_id) REFERENCES rule(id)
 );
 
 CREATE TABLE incident_rule_escalation_state (
-    incident_id bigint NOT NULL REFERENCES incident(id),
-    rule_escalation_id bigint NOT NULL REFERENCES rule_escalation(id),
+    incident_id bigint NOT NULL,
+    rule_escalation_id bigint NOT NULL,
     triggered_at bigint NOT NULL,
 
-    CONSTRAINT pk_incident_rule_escalation_state PRIMARY KEY (incident_id, rule_escalation_id)
+    CONSTRAINT pk_incident_rule_escalation_state PRIMARY KEY (incident_id, rule_escalation_id),
+    CONSTRAINT fk_incident_rule_escalation_state_incident FOREIGN KEY (incident_id) REFERENCES incident(id),
+    CONSTRAINT fk_incident_rule_escalation_state_rule_escalation FOREIGN KEY (rule_escalation_id) REFERENCES rule_escalation(id)
 );
 
 CREATE TABLE incident_history (
     id bigserial,
-    incident_id bigint NOT NULL REFERENCES incident(id),
-    rule_escalation_id bigint REFERENCES rule_escalation(id),
-    event_id bigint REFERENCES event(id),
-    contact_id bigint REFERENCES contact(id),
-    contactgroup_id bigint REFERENCES contactgroup(id),
-    schedule_id bigint REFERENCES schedule(id),
-    rule_id bigint REFERENCES rule(id),
-    channel_id bigint REFERENCES channel(id),
+    incident_id bigint NOT NULL,
+    rule_escalation_id bigint,
+    event_id bigint,
+    contact_id bigint,
+    contactgroup_id bigint,
+    schedule_id bigint,
+    rule_id bigint,
+    channel_id bigint,
     time bigint NOT NULL,
     message text,
     type incident_history_event_type NOT NULL,
@@ -438,7 +473,15 @@ CREATE TABLE incident_history (
     sent_at bigint,
 
     CONSTRAINT pk_incident_history PRIMARY KEY (id),
-    FOREIGN KEY (incident_id, rule_escalation_id) REFERENCES incident_rule_escalation_state(incident_id, rule_escalation_id)
+    CONSTRAINT fk_incident_history_incident_rule_escalation_state FOREIGN KEY (incident_id, rule_escalation_id) REFERENCES incident_rule_escalation_state(incident_id, rule_escalation_id),
+    CONSTRAINT fk_incident_history_incident FOREIGN KEY (incident_id) REFERENCES incident(id),
+    CONSTRAINT fk_incident_history_rule_escalation FOREIGN KEY (rule_escalation_id) REFERENCES rule_escalation(id),
+    CONSTRAINT fk_incident_history_event FOREIGN KEY (event_id) REFERENCES event(id),
+    CONSTRAINT fk_incident_history_contact FOREIGN KEY (contact_id) REFERENCES contact(id),
+    CONSTRAINT fk_incident_history_contactgroup FOREIGN KEY (contactgroup_id) REFERENCES contactgroup(id),
+    CONSTRAINT fk_incident_history_schedule FOREIGN KEY (schedule_id) REFERENCES schedule(id),
+    CONSTRAINT fk_incident_history_rule FOREIGN KEY (rule_id) REFERENCES rule(id),
+    CONSTRAINT fk_incident_history_channel FOREIGN KEY (channel_id) REFERENCES channel(id)
 );
 
 CREATE INDEX idx_incident_history_time_type ON incident_history(time, type);
diff --git a/schema/pgsql/upgrades/033.sql b/schema/pgsql/upgrades/033.sql
new file mode 100644
index 000000000..b074585da
--- /dev/null
+++ b/schema/pgsql/upgrades/033.sql
@@ -0,0 +1,62 @@
+ALTER TABLE channel RENAME CONSTRAINT channel_type_fkey TO fk_channel_available_channel_type;
+ALTER TABLE contact RENAME CONSTRAINT contact_username_key TO uk_contact_username;
+ALTER TABLE contact RENAME CONSTRAINT contact_default_channel_id_fkey TO fk_contact_channel;
+ALTER TABLE contact_address RENAME CONSTRAINT contact_address_contact_id_fkey TO fk_contact_address_contact;
+ALTER TABLE contactgroup_member RENAME CONSTRAINT contactgroup_member_contact_id_fkey TO fk_contactgroup_member_contact;
+ALTER TABLE contactgroup_member RENAME CONSTRAINT contactgroup_member_contactgroup_id_fkey TO fk_contactgroup_member_contactgroup;
+ALTER TABLE rotation RENAME CONSTRAINT rotation_schedule_id_priority_first_handoff_key TO uk_rotation_schedule_schedule_priority_first_handoff;
+ALTER TABLE rotation RENAME CONSTRAINT rotation_check TO ck_rotation_deleted_priority_first_handoff;
+ALTER TABLE rotation RENAME CONSTRAINT rotation_schedule_id_fkey TO fk_rotation_schedule;
+ALTER TABLE timeperiod RENAME CONSTRAINT timeperiod_owned_by_rotation_id_fkey TO fk_timeperiod_rotation;
+ALTER TABLE rotation_member RENAME CONSTRAINT rotation_member_rotation_id_position_key TO uk_rotation_member_rotation_position;
+ALTER TABLE rotation_member RENAME CONSTRAINT rotation_member_rotation_id_contact_id_key TO uk_rotation_member_rotation_contact;
+ALTER TABLE rotation_member RENAME CONSTRAINT rotation_member_rotation_id_contactgroup_id_key TO uk_rotation_member_rotation_contactgroup;
+ALTER TABLE rotation_member RENAME CONSTRAINT rotation_member_rotation_id_fkey TO fk_rotation_member_rotation;
+ALTER TABLE rotation_member RENAME CONSTRAINT rotation_member_contact_id_fkey TO fk_rotation_member_contact;
+ALTER TABLE rotation_member RENAME CONSTRAINT rotation_member_contactgroup_id_fkey TO fk_rotation_member_contactgroup;
+ALTER TABLE timeperiod_entry RENAME CONSTRAINT timeperiod_entry_timeperiod_id_fkey TO fk_timeperiod_entry_timeperiod;
+ALTER TABLE timeperiod_entry RENAME CONSTRAINT timeperiod_entry_rotation_member_id_fkey TO fk_timeperiod_entry_rotation_member;
+ALTER TABLE source RENAME CONSTRAINT source_listener_password_hash_check TO ck_bcrypt_source_listener_password_hash;
+ALTER TABLE source RENAME CONSTRAINT source_check TO ck_source_icinga2_has_config;
+ALTER TABLE object RENAME CONSTRAINT object_id_check TO ck_object_id_is_sha256;
+ALTER TABLE object RENAME CONSTRAINT object_source_id_fkey TO fk_object_source;
+ALTER TABLE object_id_tag RENAME CONSTRAINT object_id_tag_object_id_fkey TO fk_object_id_tag_object;
+ALTER TABLE object_extra_tag RENAME CONSTRAINT object_extra_tag_object_id_fkey TO fk_object_extra_tag_object;
+ALTER TABLE event RENAME CONSTRAINT event_object_id_fkey TO fk_event_object;
+ALTER TABLE rule RENAME CONSTRAINT rule_timeperiod_id_fkey TO fk_rule_timeperiod;
+ALTER TABLE rule_escalation RENAME CONSTRAINT rule_escalation_rule_id_position_key TO uk_rule_escalation_rule_position;
+ALTER TABLE rule_escalation RENAME CONSTRAINT rule_escalation_rule_id_fkey TO fk_rule_escalation_rule;
+ALTER TABLE rule_escalation RENAME CONSTRAINT rule_escalation_fallback_for_fkey TO fk_rule_escalation_rule_escalation;
+ALTER TABLE rule_escalation_recipient RENAME CONSTRAINT rule_escalation_recipient_check TO ck_rule_escalation_recipient_one_recipient;
+ALTER TABLE rule_escalation_recipient RENAME CONSTRAINT rule_escalation_recipient_rule_escalation_id_fkey TO fk_rule_escalation_recipient_rule_escalation;
+ALTER TABLE rule_escalation_recipient RENAME CONSTRAINT rule_escalation_recipient_contact_id_fkey TO fk_rule_escalation_recipient_contact;
+ALTER TABLE rule_escalation_recipient RENAME CONSTRAINT rule_escalation_recipient_contactgroup_id_fkey TO fk_rule_escalation_recipient_contactgroup;
+ALTER TABLE rule_escalation_recipient RENAME CONSTRAINT rule_escalation_recipient_schedule_id_fkey TO fk_rule_escalation_recipient_schedule;
+ALTER TABLE rule_escalation_recipient RENAME CONSTRAINT rule_escalation_recipient_channel_id_fkey TO fk_rule_escalation_recipient_channel;
+ALTER TABLE incident RENAME CONSTRAINT incident_object_id_fkey TO fk_incident_object;
+ALTER TABLE incident_event RENAME CONSTRAINT incident_event_incident_id_fkey TO fk_incident_event_incident;
+ALTER TABLE incident_event RENAME CONSTRAINT incident_event_event_id_fkey TO fk_incident_event_event;
+ALTER TABLE incident_contact RENAME CONSTRAINT key_incident_contact_contact TO uk_incident_contact_contact;
+ALTER TABLE incident_contact RENAME CONSTRAINT key_incident_contact_contactgroup TO uk_incident_contact_contactgroup;
+ALTER TABLE incident_contact RENAME CONSTRAINT key_incident_contact_schedule TO uk_incident_contact_schedule;
+ALTER TABLE incident_contact RENAME CONSTRAINT nonnulls_incident_recipients_check TO ck_incident_contact_one_recipient;
+ALTER TABLE incident_contact RENAME CONSTRAINT incident_contact_incident_id_fkey TO fk_incident_contact_incident;
+ALTER TABLE incident_contact RENAME CONSTRAINT incident_contact_contact_id_fkey TO fk_incident_contact_contact;
+ALTER TABLE incident_contact RENAME CONSTRAINT incident_contact_contactgroup_id_fkey TO fk_incident_contact_contactgroup;
+ALTER TABLE incident_contact RENAME CONSTRAINT incident_contact_schedule_id_fkey TO fk_incident_contact_schedule;
+ALTER TABLE incident_rule RENAME CONSTRAINT incident_rule_incident_id_fkey TO fk_incident_rule_incident;
+ALTER TABLE incident_rule RENAME CONSTRAINT incident_rule_rule_id_fkey TO fk_incident_rule_rule;
+ALTER TABLE incident_rule_escalation_state RENAME CONSTRAINT incident_rule_escalation_state_incident_id_fkey TO fk_incident_rule_escalation_state_incident;
+ALTER TABLE incident_rule_escalation_state RENAME CONSTRAINT incident_rule_escalation_state_rule_escalation_id_fkey TO fk_incident_rule_escalation_state_rule_escalation;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_incident_id_fkey TO fk_incident_history_incident;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_rule_escalation_id_fkey TO fk_incident_history_rule_escalation;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_event_id_fkey TO fk_incident_history_event;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_contact_id_fkey TO fk_incident_history_contact;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_contactgroup_id_fkey TO fk_incident_history_contactgroup;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_schedule_id_fkey TO fk_incident_history_schedule;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_rule_id_fkey TO fk_incident_history_rule;
+ALTER TABLE incident_history RENAME CONSTRAINT incident_history_channel_id_fkey TO fk_incident_history_channel;
+
+ALTER TABLE incident_history DROP CONSTRAINT IF EXISTS incident_history_incident_id_fkey1; -- PostgreSQL 11
+ALTER TABLE incident_history DROP CONSTRAINT IF EXISTS incident_history_incident_id_rule_escalation_id_fkey; -- PostgreSQL 12
+ALTER TABLE incident_history ADD CONSTRAINT fk_incident_history_incident_rule_escalation_state FOREIGN KEY (incident_id, rule_escalation_id) REFERENCES incident_rule_escalation_state(incident_id, rule_escalation_id);