Query goal: | Find base table columns with CHAR(n) or VARCHAR(n) type and make sure that n is not too big or too small. Also make sure that you do not use CHAR(n) in case of columns that have to keep variable length strings. "Values of type character are physically padded with spaces to the specified width n, and are stored and displayed that way" (https://www.postgresql.org/docs/current/datatype-character.html) |
Notes about the query: | Query returns also information about columns that properties have been specified through a domain. |
Query type: | General (Overview of some aspect of the database.) |
Query license: | MIT License |
Fixing suggestion: | Change the field size. If the column is specified through a domain, then you have to create a new domain and associate the column with the new domain because you cannot change the field size with the ALTER DOMAIN statement. |
Data source: | INFORMATION_SCHEMA only |
SQL query: | Click on query to copy it
SELECT table_schema, table_name, column_name, data_type, character_maximum_length FROM INFORMATION_SCHEMA.columns WHERE data_type LIKE '%char%' AND character_maximum_length IS NOT NULL 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 data_type, character_maximum_length DESC, table_schema, table_name, ordinal_position; |
Collection name | Collection description |
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Find problems by overview | Queries that results point to different aspects of database that might have problems. A human reviewer has to decide based on the results as to whether there are problems or not . |
Category name | Category description |
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Data types | Queries of this category provide information about the data types and their usage. |