Unlike MyISAM tables where you can disable indexes using ALTER TABLE...DISABLE KEYS, InnoDB handles foreign keys differently due to its ACID-compliant nature. InnoDB maintains referential integrity through foreign key constraints, which cannot be simply "disabled" like standard indexes.

When you need to temporarily bypass foreign key checks during data operations, consider these approaches:

-- Method 1: Disable foreign key checks session-wide
SET FOREIGN_KEY_CHECKS = 0;

-- Perform your operations here
INSERT INTO child_table VALUES (5, 'test', 999); -- Parent with id 999 might not exist

-- Re-enable checks
SET FOREIGN_KEY_CHECKS = 1;

Be extremely cautious when using FOREIGN_KEY_CHECKS=0 as it may lead to:

• Orphaned records in child tables
• Data integrity violations
• Cascading effects when re-enabling constraints

For more controlled operations, you can drop and recreate constraints:

-- Remove the constraint
ALTER TABLE child_table DROP FOREIGN KEY fk_name;

-- Perform your data operations
UPDATE parent_table SET id = 1000 WHERE id = 999;

-- Recreate the constraint
ALTER TABLE child_table 
ADD CONSTRAINT fk_name 
FOREIGN KEY (parent_id) REFERENCES parent_table(id)
ON DELETE CASCADE;

For atomic operations, wrap your changes in a transaction:

START TRANSACTION;
SET FOREIGN_KEY_CHECKS = 0;
-- Bulk insert/update operations here
SET FOREIGN_KEY_CHECKS = 1;
COMMIT;

Unlike MyISAM which supports ALTER TABLE ... DISABLE KEYS, InnoDB's architecture fundamentally prevents true index disabling. This stems from InnoDB's clustered index design where the primary key is physically stored with row data (the "index-organized table" concept).

Three technical constraints explain this limitation:

1. Primary Key Integrity: The PK is integral to row storage
2. MVCC Implementation: Secondary indexes contain transaction visibility information
3. Crash Recovery: All indexes must be consistent for ACID compliance

When importing large datasets, consider these approaches instead of index disabling:

Option 1: Drop and Recreate Indexes

-- Before bulk load
ALTER TABLE large_dataset DROP INDEX idx_secondary;

-- After load completes  
ALTER TABLE large_dataset ADD INDEX idx_secondary (important_column);

Option 2: Transaction Isolation

SET autocommit=0;
SET unique_checks=0;
SET foreign_key_checks=0;

-- Bulk insert statements here

COMMIT;
SET unique_checks=1;
SET foreign_key_checks=1;

Option 3: Partitioned Loading

INSERT INTO target_table SELECT * FROM source_data
WHERE id BETWEEN 1 AND 100000;

-- Repeat in batches with different ranges

For modern SSDs, index maintenance during inserts is often cheaper than complete rebuilds. Test both approaches with your specific workload:

-- Compare methods
EXPLAIN ANALYZE INSERT INTO test_table SELECT * FROM large_source;
vs.
EXPLAIN ANALYZE 
  ALTER TABLE test_table DROP INDEX idx1;
  INSERT INTO test_table SELECT * FROM large_source;
  ALTER TABLE test_table ADD INDEX idx1 (col1);

For truly massive one-time imports where downtime is acceptable, temporary MyISAM conversion might help:

ALTER TABLE temporary_import ENGINE=MyISAM;
ALTER TABLE temporary_import DISABLE KEYS;
-- Bulk load operations
ALTER TABLE temporary_import ENABLE KEYS;
ALTER TABLE temporary_import ENGINE=InnoDB;