MYSQL, slow performance group by with multiples tables with millions rows - mysql

Question

I have three table with more than 1 millions of rows and one of my query take more than 30 seconds with a date range of 3 months. I have tried multiples index and I think I have respect index orders. I don't know what to do go get a better performance.
Here my query, create table statement, in my explain
SELECT
MAX(table2.id) as item_id,
MAX(table2.sampled_inspected) as sample_size,
table1.group_col AS ass_group_id
FROM
table1
INNER JOIN table2 ON table1.id = table2.assignment_id
LEFT OUTER JOIN table3 ON table1.po_id = table3.id
LEFT JOIN table4 ON table4.id = table3.supplier_id
LEFT JOIN table5 ON table5.id = table3.project_id
WHERE table1.recycled=0
AND table2.inspection_status_id > 0
AND table2.inspection_status_id != 50
AND table3.importer_id = 215 AND table5.recycled = 0 AND table3.project_id IN ( '2062','2063','2064','2065' ) AND table2.inspection_completed_date >= DATE('2019-10-01') AND table2.inspection_completed_date <= DATE('2020-01-29')
GROUP BY ass_group_id
and here my 5 tables
CREATE TABLE `table1` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`recycled` int(1) NOT NULL DEFAULT '0',
`group_col` varchar(25) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`po_id` int(11) unsigned DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `index_assignment_po` (`po_id`),
KEY `recycled` (`recycled`,`group_col`),
KEY `group_col` (`group_col`)
) ENGINE=InnoDB AUTO_INCREMENT=3324705 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `table2` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`assignment_id` int(10) unsigned DEFAULT NULL,
`sampling_size` int(11) DEFAULT NULL,
`notes` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`photo_report` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`inspection_status_id` int(11) DEFAULT '0',
`inspection_result_id` int(1) NOT NULL DEFAULT '0',
`inspection_completed_date` datetime DEFAULT NULL,
`recycled` int(1) NOT NULL DEFAULT '0',
`qty_to_inspect` decimal(11,2) DEFAULT NULL,
`defect_rate` decimal(16,13) DEFAULT NULL,
`sampled_inspected` int(11) unsigned DEFAULT NULL,
`inspection_report_id` int(11) unsigned DEFAULT NULL,
`poline_id` int(11) unsigned DEFAULT NULL,
`item_status_id` int(11) NOT NULL DEFAULT '0',
`production_line` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `FK_wsxix_assignments` (`assignment_id`),
KEY `index_inspection_report_reportid` (`inspection_report_id`),
KEY `index_ai_inspection_completed_date` (`inspection_completed_date`),
KEY `index_item_poline` (`poline_id`),
KEY `index_item_poline_assignment` (`poline_id`,`assignment_id`),
KEY `wsxix_assignments_items_inspection_status_id` (`inspection_status_id`),
KEY `wsxix_assignments_items_inspection_result_id` (`inspection_result_id`),
KEY `inspection_completed_date` (`inspection_completed_date`,`inspection_result_id`,`inspection_status_id`)
) ENGINE=InnoDB AUTO_INCREMENT=3324705 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `table3` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`buyer_id` int(11) unsigned DEFAULT NULL,
`client_id` int(11) unsigned DEFAULT NULL,
`merchandiser_user_id` int(11) unsigned DEFAULT NULL,
`factory_id` int(11) unsigned DEFAULT NULL,
`dc_id` int(11) unsigned DEFAULT NULL,
`parent_id` int(10) unsigned DEFAULT NULL,
`supplier_id` int(11) unsigned NOT NULL,
`importer_id` int(11) unsigned NOT NULL,
`project_id` int(11) unsigned NOT NULL,
`tier_two_id` int(11) unsigned DEFAULT NULL,
`store_id` int(11) unsigned DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `buyer_id` (`buyer_id`),
KEY `client_id` (`client_id`),
KEY `merchandiser_user_id` (`merchandiser_user_id`),
KEY `FK_po_factory_companies_id` (`factory_id`),
KEY `FK_po_dc_companies_id` (`dc_id`),
KEY `index_po_parentid` (`parent_id`),
KEY `index_purchaseorders_cie` (`supplier_id`),
KEY `index_poimporter_cie` (`importer_id`),
KEY `index_purchaseorders_project` (`project_id`),
KEY `facory_importer_id` (`factory_id`,`importer_id`),
KEY `posu` (`project_id`,`supplier_id`),
KEY `store_id` (`store_id`),
KEY `tier_two_id` (`tier_two_id`)
) ENGINE=InnoDB AUTO_INCREMENT=34959 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `table4` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`parent_company_id` int(11) DEFAULT NULL,
`name` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `parent_company_id` (`parent_company_id`)
) ENGINE=InnoDB AUTO_INCREMENT=272 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `table5` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
`recycled` int(1) NOT NULL DEFAULT '0',
PRIMARY KEY (`id`),
KEY `recycled` (`recycled`)
) ENGINE=InnoDB AUTO_INCREMENT=2066 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

Answer 1

Add these indexes:
table2: (assignment_id, inspection_completed_date)
table2: (inspection_completed_date, assignment_id)
table3: (importer_id, project_id, supplier_id, id)
table3: (project_id, importer_id, supplier_id, id)
table5: (recycled, id)
table1: (recycled, po_id, id, group_col)
Remove this; it adds nothing, but slows down the query:
LEFT JOIN table4 ON table4.id = table3.supplier_id