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Median and average of the length of names of database objects

Query goal: "Names in software are 90 percent of what make software readable. You need to take the time to choose them wisely and keep them relevant. Names are too important to treat carelessly. Names should not cause confusion." (Robert C. Martin, Clean Code) Names should be expressive. Find the median length and average (arithmetic mean) length of the names (identifiers) of user-defined database objects. The values could be used to compare different databases.
Notes about the query: The query does not consider objects that are a part of an extension. The test creates a user-defined aggregate function that should be dropped in the end (see the garbage collection).
Query type: Sofware measure (Numeric values (software measures) about the database)
Query license: MIT License
Data source: INFORMATION_SCHEMA+system catalog
SQL query: Click on query to copy it

CREATE OR REPLACE FUNCTION _final_median(NUMERIC[])
   RETURNS NUMERIC AS
$$
   SELECT AVG(val)
   FROM (
     SELECT val
     FROM unnest($1) val
     ORDER BY 1
     LIMIT  2 - MOD(array_upper($1, 1), 2)
     OFFSET CEIL(array_upper($1, 1) / 2.0) - 1
   ) sub;
$$
LANGUAGE 'sql' IMMUTABLE;
CREATE OR REPLACE AGGREGATE median(NUMERIC) (
  SFUNC=array_append,
  STYPE=NUMERIC[],
  FINALFUNC=_final_median,
  INITCOND='{}'
);

WITH named_objects AS (

SELECT 
 n.oid,
 ''::text AS container_name, 
'DATABASE' AS container_type,
n.nspname AS object_name,
'SCHEMA' AS object_type
FROM pg_namespace AS n INNER JOIN pg_authid AS a ON n.nspowner=a.oid
WHERE (n.nspname='public' OR a.rolname<>'postgres')

UNION SELECT 
c.oid,
n.nspname AS container_name, 
'SCHEMA' AS container_type,
c.relname AS object_name,
CASE WHEN c.relkind='r' THEN 'BASE TABLE'
WHEN c.relkind='S' THEN 'SEQUENCE GENERATOR'
WHEN c.relkind='v' THEN 'VIEW'
WHEN c.relkind='m' THEN 'MATERIALIZED VIEW'
WHEN c.relkind='c' THEN 'COMPOSITE TYPE'
WHEN c.relkind='f' THEN 'FOREIGN TABLE'
WHEN c.relkind='p' THEN 'PARTITIONED TABLE'
WHEN c.relkind='I' THEN 'PARTITIONED INDEX'
END AS object_type
FROM pg_namespace AS n INNER JOIN pg_authid AS a ON n.nspowner=a.oid
INNER JOIN pg_class AS c ON n.oid=c.relnamespace
WHERE (n.nspname='public' OR a.rolname<>'postgres')
AND relkind NOT IN ('t','i')

UNION SELECT 
c.oid,
n.nspname AS container_name, 
'SCHEMA' AS container_type,
c.relname AS object_name,
'INDEX' AS object_type
FROM pg_namespace AS n INNER JOIN pg_authid AS a ON n.nspowner=a.oid
INNER JOIN pg_class AS c ON n.oid=c.relnamespace
INNER JOIN pg_index AS i ON i.indexrelid=c.oid
WHERE (n.nspname='public' OR a.rolname<>'postgres')
AND i.indisprimary = FALSE 
AND i.indisexclusion =FALSE

UNION ALL SELECT 
pt.oid,
n.nspname AS container_name, 
'SCHEMA' AS container_type,
pt.typname AS object_name,
CASE WHEN pt.typtype='d' THEN 'DOMAIN'
WHEN pt.typtype='e' THEN 'ENUMERATION TYPE'
WHEN pt.typtype='r' THEN 'RANGE TYPE' END AS object_type
FROM pg_namespace AS n INNER JOIN pg_authid AS a ON n.nspowner=a.oid
INNER JOIN pg_type AS pt ON n.oid=pt.typnamespace
WHERE (n.nspname='public' OR a.rolname<>'postgres')
AND pt.typtype NOT IN ('b','c')

UNION SELECT
o.oid,
n.nspname || '.' || c.relname AS container_name,
CASE WHEN c.relkind='r' THEN 'BASE TABLE'
WHEN c.relkind='v' THEN 'VIEW'
WHEN c.relkind='m' THEN 'MATERIALIZED VIEW'
WHEN c.relkind='f' THEN 'FOREIGN TABLE'
WHEN c.relkind='p' THEN 'PARTITIONED TABLE'
ELSE 'TABLE' END AS container_type,
conname AS object_name,
CASE WHEN o.contype='p' THEN 'PRIMARY KEY'
WHEN o.contype='u' THEN 'UNIQUE'
WHEN o.contype='f' THEN 'FOREIGN KEY'
WHEN o.contype='c' THEN 'TABLE CHECK'
WHEN o.contype='x' THEN 'EXCLUDE'
WHEN o.contype='t' THEN 'CONSTRAINT TRIGGER' END AS object_type
FROM pg_constraint o INNER JOIN pg_class c ON o.conrelid=c.oid
INNER JOIN pg_namespace AS n ON n.oid=c.relnamespace
INNER JOIN pg_authid AS a ON n.nspowner=a.oid
WHERE (nspname='public' OR rolname<>'postgres')

UNION SELECT 
NULL AS oid,
domain_schema || '.' || domain_name  AS container_name,
'DOMAIN' AS container_type,
constraint_name AS object_name, 
'DOMAIN CHECK' AS object_type
FROM INFORMATION_SCHEMA.domain_constraints
INNER JOIN INFORMATION_SCHEMA.check_constraints AS cc USING (constraint_schema, constraint_name)
WHERE domain_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 NOT LIKE '%IS NOT NULL'

UNION ALL SELECT 
pc.oid,
n.nspname AS container_name, 
'SCHEMA' AS container_type,
pc.proname AS object_name,
CASE WHEN pc.prokind='f' THEN 'FUNCTION'
WHEN pc.prokind='p' THEN 'PROCEDURE'
WHEN pc.prokind='a' THEN 'AGGREGATE FUNCTION'
WHEN pc.prokind='w' THEN 'WINDOW FUNCTION' END AS object_type
FROM pg_namespace AS n INNER JOIN pg_authid AS a ON n.nspowner=a.oid
INNER JOIN pg_proc AS pc ON n.oid=pc.pronamespace
WHERE (nspname='public' OR rolname<>'postgres')

UNION SELECT 
translate(substring(specific_name,'_[0-9]+$'),'_','')::int::oid,
specific_schema || '.' || regexp_replace(specific_name,'_[0-9]*$','') AS container_name, 
'ROUTINE' AS container_type,
parameter_name AS object_name, 
 'PARAMETER' AS object_type
FROM information_schema.parameters
WHERE specific_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 parameter_name IS NOT NULL

UNION SELECT 
tr.oid,
n.nspname || '.' || c.relname AS container_name,
CASE WHEN c.relkind='r' THEN 'BASE TABLE'
WHEN c.relkind='v' THEN 'VIEW'
WHEN c.relkind='m' THEN 'MATERIALIZED VIEW'
WHEN c.relkind='f' THEN 'FOREIGN TABLE'
WHEN c.relkind='p' THEN 'PARTITIONED TABLE'
ELSE 'TABLE' END AS container_type,
tr.tgname AS object_name,
'TRIGGER' AS object_type
FROM pg_trigger tr INNER JOIN pg_class c ON tr.tgrelid=c.oid
INNER JOIN pg_namespace AS n ON n.oid=c.relnamespace
INNER JOIN pg_authid AS a ON n.nspowner=a.oid
WHERE (n.nspname='public' OR a.rolname<>'postgres')
AND tr.tgisinternal='f'
AND tr.tgconstraint=0

UNION SELECT 
NULL AS oid,
schemaname || '.' || tablename AS container_name,
'TABLE' AS container_type,
rulename AS object_name,
'RULE' AS object_type
FROM pg_rules AS r
WHERE r.schemaname NOT IN (SELECT schema_name
FROM INFORMATION_SCHEMA.schemata
WHERE schema_name<>'public' AND
schema_owner='postgres' AND schema_name IS NOT NULL)

UNION SELECT 
NULL AS oid,
'' AS container_name,
'DATABASE' AS container_type,
evtname AS object_name,
'EVENT TRIGGER' AS object_type
FROM pg_event_trigger 

UNION ALL SELECT 
c.oid,
n.nspname || '.' || c.relname AS container_name,
CASE WHEN c.relkind='r' THEN 'BASE TABLE'
WHEN c.relkind='v' THEN 'VIEW'
WHEN c.relkind='m' THEN 'MATERIALIZED VIEW'
WHEN c.relkind='f' THEN 'FOREIGN TABLE'
WHEN c.relkind='p' THEN 'PARTITIONED TABLE'
ELSE 'TABLE' END AS container_type,
at.attname AS object_name,
'COLUMN' AS object_type
FROM pg_attribute at INNER JOIN pg_class c ON at.attrelid=c.oid
INNER JOIN pg_namespace AS n ON n.oid=c.relnamespace
INNER JOIN pg_authid AS a ON n.nspowner=a.oid
WHERE (nspname='public' OR rolname<>'postgres')
AND c.relkind IN ('r','v','m','f','p')
AND at.attisdropped='f'
AND at.attnum>0

),

named_user_defined_objects AS (
SELECT container_name, container_type, object_name, object_type
FROM named_objects nob
WHERE NOT EXISTS (SELECT 1
FROM pg_catalog.pg_depend d 
WHERE EXISTS (SELECT 1 FROM pg_catalog.pg_extension e WHERE d.refobjid=e.oid) AND
d.objid=nob.oid)
)

SELECT Round(Median(Length(object_name)),1) AS name_length_median, Round(Avg(Length(object_name)),1) AS name_length_average
FROM named_user_defined_objects;

DROP FUNCTION IF EXISTS _final_median(NUMERIC[]) CASCADE; DROP AGGREGATE IF EXISTS median(numeric);

Collections where the query belongs to

Collection nameCollection description
Find problems about namesA selection of queries that return information about the names of database objects. Contains all the types of queries - problem detection, software measure, and general overview.

Categories where the query belongs to

Category nameCategory description
NamingQueries of this category provide information about the style of naming.

The list of all the queries