Batched Migration

SELECT COUNT(*) as total FROM target_table;
-- Calculate: batches_needed = CEIL(total / 1000)

-- Batch 1
INSERT INTO target_table_new (id, col1, col2)
SELECT id, col1, col2 FROM target_table
ORDER BY id LIMIT 1000 OFFSET 0;

-- Batch 2
INSERT INTO target_table_new (id, col1, col2)
SELECT id, col1, col2 FROM target_table
ORDER BY id LIMIT 1000 OFFSET 1000;
-- Continue until all rows migrated...

-- First batch
INSERT INTO target_table_new (id, col1, col2)
SELECT id, col1, col2 FROM target_table
ORDER BY id LIMIT 1000;

-- Get last processed ID
SELECT MAX(id) as last_id FROM target_table_new;

-- Subsequent batches
INSERT INTO target_table_new (id, col1, col2)
SELECT id, col1, col2 FROM target_table
WHERE id > 'last_processed_id'
ORDER BY id LIMIT 1000;

SELECT (SELECT COUNT(*) FROM target_table_new) as migrated,
       (SELECT COUNT(*) FROM target_table) as total;

-- Find problematic rows
SELECT id, problematic_column FROM target_table
WHERE problematic_column !~ '^-?[0-9]+$' LIMIT 100;

-- Check table state
SELECT table_name FROM information_schema.tables
WHERE table_name IN ('target_table', 'target_table_new');