Find base table columns that have type NUMERIC and the scale is 0, i.e., one can record in the column only integer values. Arithmetic operations are slower in case of the numeric type compared to an integer type. Thus, in order to record integer values, one should use columns with the type SMALLINT, INTEGER, or BIGINT instead of NUMERIC(p,0).
Type
Problem detection (Each row in the result could represent a flaw in the design)
Change the data type to SMALLINT, INTEGER, or BIGINT. If the column has been defined based on a domain, then change the underlying type of domain. In case changing the type of a domain one has to drop and recreate the domain and associate the recreated domain again with all the columns with which it was previously associated.
Data Source
INFORMATION_SCHEMA only
SQL Query
SELECT table_schema, table_name, column_name, data_type, numeric_precision, numeric_scale, CASE WHEN numeric_precision<5 THEN 'SMALLINT' WHEN numeric_precision BETWEEN 5 AND 9 THEN 'INTEGER' ELSE 'BIGINT' END AS suggested_type
FROM INFORMATION_SCHEMA.columns
WHERE data_type IN ('decimal', 'numeric')
AND (table_schema, table_name) IN (SELECT table_schema, table_name
FROM INFORMATION_SCHEMA.tables WHERE table_type='BASE TABLE')
AND table_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
AND (numeric_scale=0)
ORDER BY table_schema, table_name, ordinal_position;
SQL statements that help generate fixes for the identified problem.
SQL Query to Generate Fix
Description
SELECT format('ALTER TABLE %1$I.%2$I ALTER COLUMN %3$I SET DATA TYPE %4$s;', table_schema, table_name, column_name, CASE WHEN numeric_precision<5 THEN 'SMALLINT' WHEN numeric_precision BETWEEN 5 AND 9 THEN 'INTEGER' ELSE 'BIGINT' END) AS statements
FROM INFORMATION_SCHEMA.columns
WHERE data_type IN ('decimal', 'numeric')
AND (table_schema, table_name) IN (SELECT table_schema, table_name
FROM INFORMATION_SCHEMA.tables WHERE table_type='BASE TABLE')
AND table_schema NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)
AND (numeric_scale=0)
AND domain_name IS NULL
ORDER BY table_schema, table_name, ordinal_position;
Change type of the column if the column is not defined based on a domain.
Collections
This query belongs to the following collections:
Name
Description
Find problems automatically
Queries, that results point to problems in the database. Each query in the collection produces an initial assessment. However, a human reviewer has the final say as to whether there is a problem or not .
Categories
This query is classified under the following categories:
Name
Description
Data types
Queries of this category provide information about the data types and their usage.
Performance
Queries of this category provide information about indexes in a database.