9a94b3879a
The return values of it can be safely used when len(schema.table_name) exceeds the 63 char limit of the postgres type `name`.
79 lines
2.1 KiB
PL/PgSQL
79 lines
2.1 KiB
PL/PgSQL
-- Return an array of table names scanned by a given query
|
|
--
|
|
-- Requires PostgreSQL 9.x+
|
|
--
|
|
CREATE OR REPLACE FUNCTION CDB_QueryTablesRegclass(query text)
|
|
RETURNS regclass[]
|
|
AS $$
|
|
DECLARE
|
|
exp XML;
|
|
tables regclass[];
|
|
rec RECORD;
|
|
rec2 RECORD;
|
|
BEGIN
|
|
|
|
tables := '{}';
|
|
|
|
FOR rec IN SELECT CDB_QueryStatements(query) q LOOP
|
|
|
|
IF NOT ( rec.q ilike 'select%' or rec.q ilike 'with%' ) THEN
|
|
--RAISE WARNING 'Skipping %', rec.q;
|
|
CONTINUE;
|
|
END IF;
|
|
|
|
BEGIN
|
|
EXECUTE 'EXPLAIN (FORMAT XML, VERBOSE) ' || rec.q INTO STRICT exp;
|
|
EXCEPTION WHEN others THEN
|
|
-- TODO: if error is 'relation "xxxxxx" does not exist', take xxxxxx as
|
|
-- the affected table ?
|
|
RAISE WARNING 'CDB_QueryTables cannot explain query: % (%: %)', rec.q, SQLSTATE, SQLERRM;
|
|
RAISE EXCEPTION '%', SQLERRM;
|
|
CONTINUE;
|
|
END;
|
|
|
|
-- Now need to extract all values of <Relation-Name>
|
|
|
|
-- RAISE DEBUG 'Explain: %', exp;
|
|
|
|
FOR rec2 IN WITH
|
|
inp AS (
|
|
SELECT
|
|
xpath('//x:Relation-Name/text()', exp, ARRAY[ARRAY['x', 'http://www.postgresql.org/2009/explain']]) as x,
|
|
xpath('//x:Relation-Name/../x:Schema/text()', exp, ARRAY[ARRAY['x', 'http://www.postgresql.org/2009/explain']]) as s
|
|
)
|
|
SELECT unnest(x) as p, unnest(s) as sc from inp
|
|
LOOP
|
|
-- RAISE DEBUG 'tab: %', rec2.p;
|
|
-- RAISE DEBUG 'sc: %', rec2.sc;
|
|
tables := array_append(tables, (rec2.sc || '.' || rec2.p)::regclass);
|
|
END LOOP;
|
|
|
|
-- RAISE DEBUG 'Tables: %', tables;
|
|
|
|
END LOOP;
|
|
|
|
-- RAISE DEBUG 'Tables: %', tables;
|
|
|
|
-- Remove duplicates and sort by name
|
|
IF array_upper(tables, 1) > 0 THEN
|
|
WITH dist as ( SELECT DISTINCT unnest(tables)::text as p ORDER BY p )
|
|
SELECT array_agg(p) from dist into tables;
|
|
END IF;
|
|
|
|
--RAISE DEBUG 'Tables: %', tables;
|
|
|
|
return tables;
|
|
END
|
|
$$ LANGUAGE 'plpgsql' VOLATILE STRICT;
|
|
|
|
|
|
-- Keep CDB_QueryTables with same signature for backwards compatibility.
|
|
-- It should probably be removed in the future.
|
|
CREATE OR REPLACE FUNCTION CDB_QueryTables(query text)
|
|
RETURNS name[]
|
|
AS $$
|
|
BEGIN
|
|
RETURN CDB_QueryTablesRegclass(query)::name[];
|
|
END
|
|
$$ LANGUAGE 'plpgsql' VOLATILE STRICT;
|