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Name and description maximum length

Query goal: Find tables where is both a column for registering name and description. Find the permitted maximum field size in these columns. Take into account that the maximum length may be controlled by using a CHECK constraint. Make sure that the permitted maximum field sizes are sufficiently different.
Notes about the query: The query considers both column names in English and Estonian.
Query type: General (Overview of some aspect of the database.)
Query license: MIT License
Data source: INFORMATION_SCHEMA+system catalog
SQL query: Click on query to copy it

WITH length_checks AS (select 
n.nspname as table_schema,
c.relname as table_name,
a.attname as column_name,
regexp_replace(pg_get_constraintdef(o.oid),'CHECK ', '','g') AS check_clause,
'TABLE CHECK' AS check_type, 
o.conname AS constraint_name
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
inner join pg_namespace n on o.connamespace=n.oid
INNER JOIN pg_attribute a ON a.attrelid = c.oid AND a.attnum = o.conkey[1] AND a.attisdropped = FALSE
where o.contype = 'c' 
AND cardinality(o.conkey)=1
AND c.relkind IN ('r', 'f')
AND regexp_replace(pg_get_constraintdef(o.oid),'CHECK ', '','g') ~*'length[(]'
UNION ALL SELECT cdu.table_schema, cdu.table_name, cdu.column_name, cc.check_clause, 'DOMAIN CHECK' AS check_type, 
d.domain_schema||'.'||d.domain_name || '.' || cc.constraint_name AS name
FROM INFORMATION_SCHEMA.column_domain_usage AS cdu INNER JOIN INFORMATION_SCHEMA.tables AS t USING (table_schema, table_name) 
INNER JOIN INFORMATION_SCHEMA.domain_constraints AS dc USING (domain_schema, domain_name) 
INNER JOIN INFORMATION_SCHEMA.domains AS d USING (domain_schema, domain_name)
INNER JOIN INFORMATION_SCHEMA.check_constraints AS cc USING (constraint_schema, constraint_name)
WHERE t.table_type IN ('BASE TABLE', 'FOREIGN') AND cc.check_clause NOT LIKE '%IS NOT NULL'  AND 
cdu.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 cc.check_clause~*'length[(]'),
columns AS (SELECT A.table_schema, A.table_name , A.column_name, CASE WHEN data_type ILIKE 'character%' AND character_maximum_length IS NOT NULL THEN data_type || '(' || character_maximum_length::text || ')'
WHEN data_type ILIKE 'timestamp%' AND datetime_precision IS NOT NULL THEN data_type || '(' || datetime_precision || ')'
WHEN data_type ILIKE 'numeric%' AND numeric_precision IS NOT NULL THEN data_type || '(' || numeric_precision::text || ',' ||coalesce(numeric_scale,0)::text || ')'
WHEN data_type ILIKE 'interval%' AND interval_type IS NOT NULL THEN data_type || '(' || interval_type::text || ')'
WHEN data_type='USER-DEFINED' THEN udt_schema || '.' || udt_name 
ELSE data_type END AS data_type
FROM information_schema.columns A INNER JOIN information_schema.tables T USING (table_schema, table_name)
INNER JOIN information_schema.schemata S ON A.table_schema=S.schema_name
WHERE T.table_type='BASE TABLE'
AND (A.table_schema = 'public'
OR S.schema_owner<>'postgres')
AND column_name~*'(nimi|nimetus|pealkiri|name|title|kirjeldus|kommentaar|selgitus|lugu|description|comment|explanation|story)')
SELECT column_name.table_schema, column_name.table_name,
column_name.column_name AS name_column, column_name.data_type AS name_column_type, lc_name.check_clause AS name_column_check, lc_name.check_type AS name_column_check_type,
column_description.column_name AS description_column, column_description.data_type AS name_column_type, lc_description.check_clause AS description_column_check, lc_description.check_type AS description_column_check_type
FROM columns AS column_name LEFT JOIN length_checks AS lc_name USING (table_schema, table_name, column_name),
columns AS column_description LEFT JOIN length_checks AS lc_description USING (table_schema, table_name, column_name)
WHERE column_name.table_schema=column_description.table_schema
AND column_name.table_name=column_description.table_name
AND column_name.column_name~*'(nimi|nimetus|pealkiri|name|title)'
AND column_description.column_name~*'(kirjeldus|kommentaar|selgitus|lugu|description|comment|explanation|story)'
ORDER BY column_name.table_schema, column_name.table_name;

Collections where the query belongs to

Collection nameCollection description
Find problems by overviewQueries 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 .

Categories where the query belongs to

Category nameCategory description
Field sizeQueries of this category provide information about the maximum size of values that can be recorded in column fields
Result quality depends on namesQueries of this category use names (for instance, column names) to try to guess the meaning of a database object. Thus, the goodness of names determines the number of false positive and false negative results.
Validity and completenessQueries of this category provide information about whether database design represents the world (domain) correctly (validity) and whether database design captures all the information about the world (domain) that is correct and relevant (completeness).

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