1. 테이블별 사이즈 확인 (쿼리 시점에 정확한 사이즈는 아니지만, 참고할 만한 데이터임)

SELECT 
    table_name,
    table_rows,
    round(data_length/(1024*1024),2) as 'DATA_SIZE(MB)',
    round(index_length/(1024*1024),2) as 'INDEX_SIZE(MB)'
FROM information_schema.TABLES
where table_schema = '데이터베이스이름'
GROUP BY table_name 
ORDER BY data_length DESC 
LIMIT 10;

2. Database 별 사이즈 확인 (쿼리 시점에 정확한 사이즈는 아니지만, 참고할 만한 데이터임)

SELECT
count(*) NUM_OF_TABLE,
table_schema,concat(round(sum(table_rows)/1000000,2),'M') rows,
concat(round(sum(data_length)/(1024*1024*1024),2),'G') DATA,
concat(round(sum(index_length)/(1024*1024*1024),2),'G') idx,
concat(round(sum(data_length+index_length)/(1024*1024*1024),2),'G') total_size,
round(sum(index_length)/sum(data_length),2) idxfrac
FROM information_schema.TABLES
GROUP BY table_schema
ORDER BY sum(data_length+index_length) DESC LIMIT 10;

3. 전체 용량

 SELECT SUM(data_length+index_length)/1024/1024 used_MB, SUM(data_free)/1024/1024 free_MB FROM information_schema.tables;

4. DB별

SELECT table_schema, SUM((data_length+index_length)/1024/1024) MB FROM information_schema.tables GROUP BY 1;