Created
November 23, 2018 18:10
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Getting the list of rows per table | |
``` | |
SELECT schemaname,relname,n_live_tup | |
FROM pg_stat_user_tables | |
ORDER BY n_live_tup DESC; | |
``` | |
search_columns | |
``` | |
CREATE OR REPLACE FUNCTION search_columns( | |
needle text, | |
haystack_tables name[] default '{}', | |
haystack_schema name[] default '{}' | |
) | |
RETURNS table(schemaname text, tablename text, columnname text, rowctid text) | |
AS $$ | |
begin | |
FOR schemaname,tablename,columnname IN | |
SELECT c.table_schema,c.table_name,c.column_name | |
FROM information_schema.columns c | |
JOIN information_schema.tables t ON | |
(t.table_name=c.table_name AND t.table_schema=c.table_schema) | |
WHERE (c.table_name=ANY(haystack_tables) OR haystack_tables='{}') | |
AND (c.table_schema=ANY(haystack_schema) OR haystack_schema='{}') | |
AND t.table_type='BASE TABLE' | |
LOOP | |
EXECUTE format('SELECT ctid FROM %I.%I WHERE cast(%I as text)=%L', | |
schemaname, | |
tablename, | |
columnname, | |
needle | |
) INTO rowctid; | |
IF rowctid is not null THEN | |
RETURN NEXT; | |
END IF; | |
END LOOP; | |
END; | |
$$ language plpgsql; | |
``` | |
Search in all tables within public schema: | |
``` | |
select * from search_columns('foobar'); | |
schemaname | tablename | columnname | rowctid | |
------------+-----------+------------+--------- | |
public | s3 | usename | (0,11) | |
public | s2 | relname | (7,29) | |
public | w | body | (0,2) | |
(3 rows) | |
Search in a specific table: | |
``` | |
select * from search_columns('foobar','{w}'); | |
schemaname | tablename | columnname | rowctid | |
------------+-----------+------------+--------- | |
public | w | body | (0,2) | |
(1 row) | |
Search in a subset of tables obtained from a select: | |
select * from search_columns('foobar', array(select table_name::name from information_schema.tables where table_name like 's%'), array['public']); | |
schemaname | tablename | columnname | rowctid | |
------------+-----------+------------+--------- | |
public | s2 | relname | (7,29) | |
public | s3 | usename | (0,11) | |
(2 rows) | |
Get a result row with the corresponding base table and and ctid: | |
select * from public.w where ctid='(0,2)'; | |
title | body | tsv | |
-------+--------+--------------------- | |
toto | foobar | 'foobar':2 'toto':1 | |
To test again a regular expression instead of strict equality, like grep, this: | |
SELECT ctid FROM %I.%I WHERE cast(%I as text)=%L | |
may be changed to: | |
SELECT ctid FROM %I.%I WHERE cast(%I as text) ~ %L | |
``` |
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