Print Out Postgresql Table Sizes

SELECT
    schemaname || '.' || tablename AS table_full_name,
    pg_size_pretty(pg_total_relation_size(quote_ident(schemaname) || '.' || quote_ident(tablename))) AS total_size
FROM pg_tables
WHERE schemaname NOT IN ('pg_catalog', 'information_schema')
ORDER BY pg_total_relation_size(quote_ident(schemaname) || '.' || quote_ident(tablename)) DESC;

Count mysql table rows (approximate)

SELECT 
    TABLE_SCHEMA,
    TABLE_NAME,
    TABLE_ROWS
FROM 
    information_schema.TABLES
WHERE 
    TABLE_TYPE = 'BASE TABLE'
    AND TABLE_SCHEMA NOT IN ('mysql', 'information_schema', 'performance_schema', 'sys')
ORDER BY 
    TABLE_ROWS DESC;

show mysql table size

SELECT 
    TABLE_SCHEMA,
    TABLE_NAME,
    ROUND((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024, 2) AS size_mb
FROM 
    information_schema.TABLES
WHERE 
    TABLE_TYPE = 'BASE TABLE'
    AND TABLE_SCHEMA NOT IN ('mysql', 'performance_schema', 'information_schema', 'sys')
ORDER BY 
    size_mb DESC;

show all unique values in a column

SELECT DISTINCT your_column
FROM your_table;