Find most used data type in Snowflake

Query below returns data types used in a database ordered by the number of their occurance.

Query

select  c.data_type,
        count(*) as columns, 
         cast(100.0 *
               count(*) / 
                   (select count(*) from information_schema.tables t
                    inner join information_schema.columns c on 
                    c.table_schema = t.table_schema 
                    and c.table_name = t.table_name
                    where table_type = 'BASE TABLE') 
       as decimal (14,2))  as percent_columns, 
       count(distinct t.table_schema || '.' ||  t.table_name ) as tables,
       cast(100.0 * 
              count(distinct t.table_schema || '.' ||  t.table_name) / 
                (select count(*) from information_schema.tables
                 where table_type = 'BASE TABLE')
       as decimal (14,2)) as percent_tables
from information_schema.tables t
inner join information_schema.columns c on 
         c.table_schema = t.table_schema and c.table_name = t.table_name
where table_type = 'BASE TABLE'   
group by c.data_type
order by count(*) desc;

Columns

  • data_type - built in or user data type without length or precision, e.g. int, varchar or date
  • columns - number of columns in a database with this data type
  • percent_columns - percentage of columns with this data type. Rows add up to 100%
  • tables - number of tables in a database with this data type
  • percent_tables - percentage of tables with columns with this data type.

Rows

  • One row represents one data type
  • Scope of rows: all data types used in a database
  • Ordered by number of columns descending

Sample results

Those results show data types used in SNOWFLAKE_SAMPLE_DATA database. As you can see most popular data type is number - it is used in 648 columns which is 58.27% of all columns in 80 tables (which 91.95% of all tables).

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