| Query goal: | Find base table columns that have FLOAT, REAL, or DOUBLE PRECISION type. "The data types real and double precision are inexact, variable-precision numeric types. On all currently supported platforms, these types are implementations of IEEE Standard 754 for Binary Floating-Point Arithmetic (single and double precision, respectively), to the extent that the underlying processor, operating system, and compiler support it." (PostgreSQL documentation) Do not use the approximate numeric types FLOAT, REAL, and DOUBLE PRECISION in order to present fractional numeric data. Due to the use of the IEEE 754 standard the results of calculations with the values, which have one of these types, can be inexact because out of necessity some numbers must be rounded to a value, which is very close. "Comparing two floating-point values for equality might not always work as expected." (PostgreSQL documentation) |
| Query type: | Problem detection (Each row in the result could represent a flaw in the design) |
| Query reliability: | High (Few or no false-positive results) |
| Query license: | MIT License |
| Fixing suggestion: | If you require exact storage and calculations (such as for monetary amounts), use the numeric type instead. |
| Data source: | INFORMATION_SCHEMA only |
| SQL query: | Click on query to copy it
SELECT table_schema, table_name, column_name, data_type
FROM INFORMATION_SCHEMA.columns
WHERE data_type IN ('real','float', 'double precision') 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)
ORDER BY table_schema, table_name, ordinal_position; |