diff --git a/superset/config.py b/superset/config.py
index 51eb9bca9..c7b05e833 100644
--- a/superset/config.py
+++ b/superset/config.py
@@ -803,6 +803,10 @@ ENABLE_SCHEDULED_EMAIL_REPORTS = False
 # if it meets the criteria
 ENABLE_ALERTS = False
 
+# Used for Alerts/Reports (Feature flask ALERT_REPORTS) to set the size for the
+# sliding cron window size, should be synced with the celery beat config minus 1 second
+ALERT_REPORTS_CRON_WINDOW_SIZE = 59
+
 # Slack API token for the superset reports
 SLACK_API_TOKEN = None
 SLACK_PROXY = None
diff --git a/superset/migrations/versions/ab104a954a8f_reports_alter_crontab_size.py b/superset/migrations/versions/ab104a954a8f_reports_alter_crontab_size.py
new file mode 100644
index 000000000..bb1a501de
--- /dev/null
+++ b/superset/migrations/versions/ab104a954a8f_reports_alter_crontab_size.py
@@ -0,0 +1,50 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""reports alter crontab size
+
+Revision ID: ab104a954a8f
+Revises: 5daced1f0e76
+Create Date: 2020-12-15 09:07:24.730545
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = "ab104a954a8f"
+down_revision = "e37912a26567"
+
+import sqlalchemy as sa
+from alembic import op
+
+
+def upgrade():
+    with op.batch_alter_table("report_schedule") as batch_op:
+        batch_op.alter_column(
+            "crontab",
+            existing_type=sa.VARCHAR(length=50),
+            type_=sa.VARCHAR(length=1000),
+            existing_nullable=False,
+        )
+
+
+def downgrade():
+    with op.batch_alter_table("report_schedule") as batch_op:
+        batch_op.alter_column(
+            "crontab",
+            existing_type=sa.VARCHAR(length=1000),
+            type_=sa.VARCHAR(length=50),
+            existing_nullable=False,
+        )
diff --git a/superset/models/reports.py b/superset/models/reports.py
index 0c2816b45..7e1ec9ce3 100644
--- a/superset/models/reports.py
+++ b/superset/models/reports.py
@@ -98,7 +98,7 @@ class ReportSchedule(Model, AuditMixinNullable):
     description = Column(Text)
     context_markdown = Column(Text)
     active = Column(Boolean, default=True, index=True)
-    crontab = Column(String(50), nullable=False)
+    crontab = Column(String(1000), nullable=False)
     sql = Column(Text())
     # (Alerts/Reports) M-O to chart
     chart_id = Column(Integer, ForeignKey("slices.id"), nullable=True)
diff --git a/superset/reports/api.py b/superset/reports/api.py
index 6be4a12f3..445474c7d 100644
--- a/superset/reports/api.py
+++ b/superset/reports/api.py
@@ -26,6 +26,7 @@ from marshmallow import ValidationError
 from superset.charts.filters import ChartFilter
 from superset.constants import MODEL_API_RW_METHOD_PERMISSION_MAP, RouteMethod
 from superset.dashboards.filters import DashboardFilter
+from superset.databases.filters import DatabaseFilter
 from superset.models.reports import ReportSchedule
 from superset.reports.commands.bulk_delete import BulkDeleteReportScheduleCommand
 from superset.reports.commands.create import CreateReportScheduleCommand
@@ -47,7 +48,12 @@ from superset.reports.schemas import (
     ReportSchedulePostSchema,
     ReportSchedulePutSchema,
 )
-from superset.views.base_api import BaseSupersetModelRestApi, statsd_metrics
+from superset.views.base_api import (
+    BaseSupersetModelRestApi,
+    RelatedFieldFilter,
+    statsd_metrics,
+)
+from superset.views.filters import FilterRelatedOwners
 
 logger = logging.getLogger(__name__)
 
@@ -155,12 +161,23 @@ class ReportScheduleRestApi(BaseSupersetModelRestApi):
     ]
     search_columns = ["name", "active", "created_by", "type", "last_state"]
     search_filters = {"name": [ReportScheduleAllTextFilter]}
-    allowed_rel_fields = {"created_by", "chart", "dashboard"}
+    allowed_rel_fields = {"owners", "chart", "dashboard", "database"}
     filter_rel_fields = {
         "chart": [["id", ChartFilter, lambda: []]],
         "dashboard": [["id", DashboardFilter, lambda: []]],
+        "database": [["id", DatabaseFilter, lambda: []]],
+    }
+    text_field_rel_fields = {
+        "dashboard": "dashboard_title",
+        "chart": "slice_name",
+        "database": "database_name",
+    }
+    related_field_filters = {
+        "dashboard": "dashboard_title",
+        "chart": "slice_name",
+        "database": "database_name",
+        "owners": RelatedFieldFilter("first_name", FilterRelatedOwners),
     }
-    text_field_rel_fields = {"dashboard": "dashboard_title"}
 
     apispec_parameter_schemas = {
         "get_delete_ids_schema": get_delete_ids_schema,
diff --git a/superset/reports/commands/alert.py b/superset/reports/commands/alert.py
index ae72bbd26..5ddeb4683 100644
--- a/superset/reports/commands/alert.py
+++ b/superset/reports/commands/alert.py
@@ -26,6 +26,7 @@ from superset import jinja_context
 from superset.commands.base import BaseCommand
 from superset.models.reports import ReportSchedule, ReportScheduleValidatorType
 from superset.reports.commands.exceptions import (
+    AlertQueryError,
     AlertQueryInvalidTypeError,
     AlertQueryMultipleColumnsError,
     AlertQueryMultipleRowsError,
@@ -47,7 +48,7 @@ class AlertCommand(BaseCommand):
         self.validate()
 
         if self._report_schedule.validator_type == ReportScheduleValidatorType.NOT_NULL:
-            self._report_schedule.last_value_row_json = self._result
+            self._report_schedule.last_value_row_json = str(self._result)
             return self._result not in (0, None, np.nan)
         self._report_schedule.last_value = self._result
         try:
@@ -60,9 +61,11 @@ class AlertCommand(BaseCommand):
             raise AlertValidatorConfigError()
 
     def _validate_not_null(self, rows: np.recarray) -> None:
+        self._validate_result(rows)
         self._result = rows[0][1]
 
-    def _validate_operator(self, rows: np.recarray) -> None:
+    @staticmethod
+    def _validate_result(rows: np.recarray) -> None:
         # check if query return more then one row
         if len(rows) > 1:
             raise AlertQueryMultipleRowsError(
@@ -80,6 +83,9 @@ class AlertCommand(BaseCommand):
                     % (len(rows[0]) - 1)
                 )
             )
+
+    def _validate_operator(self, rows: np.recarray) -> None:
+        self._validate_result(rows)
         if rows[0][1] is None:
             return
         try:
@@ -97,7 +103,10 @@ class AlertCommand(BaseCommand):
             database=self._report_schedule.database
         )
         rendered_sql = sql_template.process_template(self._report_schedule.sql)
-        df = self._report_schedule.database.get_df(rendered_sql)
+        try:
+            df = self._report_schedule.database.get_df(rendered_sql)
+        except Exception as ex:
+            raise AlertQueryError(message=str(ex))
 
         if df.empty:
             return
diff --git a/superset/reports/commands/exceptions.py b/superset/reports/commands/exceptions.py
index a4aa9d985..b25111bd4 100644
--- a/superset/reports/commands/exceptions.py
+++ b/superset/reports/commands/exceptions.py
@@ -151,6 +151,10 @@ class AlertQueryInvalidTypeError(CommandException):
     message = _("Alert query returned a non-number value.")
 
 
+class AlertQueryError(CommandException):
+    message = _("Alert found an error while executing a query.")
+
+
 class ReportScheduleAlertGracePeriodError(CommandException):
     message = _("Alert fired during grace period.")
 
diff --git a/superset/reports/logs/api.py b/superset/reports/logs/api.py
index 4b3177b73..44fdf3f0a 100644
--- a/superset/reports/logs/api.py
+++ b/superset/reports/logs/api.py
@@ -22,7 +22,7 @@ from flask_appbuilder.api import expose, permission_name, protect, rison, safe
 from flask_appbuilder.api.schemas import get_item_schema, get_list_schema
 from flask_appbuilder.models.sqla.interface import SQLAInterface
 
-from superset.constants import RouteMethod
+from superset.constants import MODEL_API_RW_METHOD_PERMISSION_MAP, RouteMethod
 from superset.models.reports import ReportExecutionLog
 from superset.reports.logs.schemas import openapi_spec_methods_override
 from superset.views.base_api import BaseSupersetModelRestApi
@@ -34,6 +34,8 @@ class ReportExecutionLogRestApi(BaseSupersetModelRestApi):
     datamodel = SQLAInterface(ReportExecutionLog)
 
     include_route_methods = {RouteMethod.GET, RouteMethod.GET_LIST}
+    method_permission_name = MODEL_API_RW_METHOD_PERMISSION_MAP
+
     class_permission_name = "ReportSchedule"
     resource_name = "report"
     allow_browser_login = True
diff --git a/superset/reports/schemas.py b/superset/reports/schemas.py
index 777a56a10..10dc472f9 100644
--- a/superset/reports/schemas.py
+++ b/superset/reports/schemas.py
@@ -139,7 +139,7 @@ class ReportSchedulePostSchema(Schema):
     active = fields.Boolean()
     crontab = fields.String(
         description=crontab_description,
-        validate=[validate_crontab, Length(1, 50)],
+        validate=[validate_crontab, Length(1, 1000)],
         example="*/5 * * * *",
         allow_none=False,
         required=True,
@@ -192,7 +192,7 @@ class ReportSchedulePutSchema(Schema):
     active = fields.Boolean(required=False)
     crontab = fields.String(
         description=crontab_description,
-        validate=[validate_crontab, Length(1, 50)],
+        validate=[validate_crontab, Length(1, 1000)],
         required=False,
     )
     sql = fields.String(
diff --git a/superset/tasks/scheduler.py b/superset/tasks/scheduler.py
index 0ac0ce397..6012cba9f 100644
--- a/superset/tasks/scheduler.py
+++ b/superset/tasks/scheduler.py
@@ -20,6 +20,7 @@ from typing import Iterator
 
 import croniter
 
+from superset import app
 from superset.commands.exceptions import CommandException
 from superset.extensions import celery_app
 from superset.reports.commands.execute import AsyncExecuteReportScheduleCommand
@@ -30,7 +31,8 @@ from superset.utils.celery import session_scope
 logger = logging.getLogger(__name__)
 
 
-def cron_schedule_window(cron: str, window_size: int = 10) -> Iterator[datetime]:
+def cron_schedule_window(cron: str) -> Iterator[datetime]:
+    window_size = app.config["ALERT_REPORTS_CRON_WINDOW_SIZE"]
     utc_now = datetime.utcnow()
     start_at = utc_now - timedelta(seconds=1)
     stop_at = utc_now + timedelta(seconds=window_size)
diff --git a/tests/reports/api_tests.py b/tests/reports/api_tests.py
index 97aecea4b..6422d02f9 100644
--- a/tests/reports/api_tests.py
+++ b/tests/reports/api_tests.py
@@ -370,7 +370,7 @@ class TestReportSchedulesApi(SupersetTestCase):
         ReportSchedule Api: Test get releated report schedule
         """
         self.login(username="admin")
-        related_columns = ["created_by", "chart", "dashboard"]
+        related_columns = ["owners", "chart", "dashboard", "database"]
         for related_column in related_columns:
             uri = f"api/v1/report/related/{related_column}"
             rv = self.client.get(uri)