mysql - Table with many columns or many small tables? -

i created table has 30 columns.

create table "settings" (   "column1" integer primary key,   ...   ...   "column30" ) 

however, can group them , create different table can have foreign keys primary table. best way follow? or number of columns small it's same way follow?

it depends on data , query do.

best 1 big table

• if need extract columns always
• if need update many fields @ same time
• if fields or quite have not null values

best many little tables

• if data "sparse" means not many columns have values can imagine split them in different tables , create record in child table if not null values exists
• if extract few related fields @ 1 time
• if update related fields @ 1 time
• better names each column (for example instead of domicile_address , residence_address can have 2 columns named address in 2 tables residences , domiciles)

the problem can use both solutions depending situation. usage analysis must done choose right one.