我正在寻找一种方法,为我在Postgres中所有的表找到行数。我知道我可以一次做一张表:
SELECT count(*) FROM table_name;
但我想看看所有表的行数,然后按它排序,以了解所有表的大小。
我正在寻找一种方法,为我在Postgres中所有的表找到行数。我知道我可以一次做一张表:
SELECT count(*) FROM table_name;
但我想看看所有表的行数,然后按它排序,以了解所有表的大小。
当前回答
我做了一个小的变化,包括所有的表,也是非公共的表。
CREATE TYPE table_count AS (table_schema TEXT,table_name TEXT, num_rows INTEGER);
CREATE OR REPLACE FUNCTION count_em_all () RETURNS SETOF table_count AS '
DECLARE
the_count RECORD;
t_name RECORD;
r table_count%ROWTYPE;
BEGIN
FOR t_name IN
SELECT table_schema,table_name
FROM information_schema.tables
where table_schema !=''pg_catalog''
and table_schema !=''information_schema''
ORDER BY 1,2
LOOP
FOR the_count IN EXECUTE ''SELECT COUNT(*) AS "count" FROM '' || t_name.table_schema||''.''||t_name.table_name
LOOP
END LOOP;
r.table_schema := t_name.table_schema;
r.table_name := t_name.table_name;
r.num_rows := the_count.count;
RETURN NEXT r;
END LOOP;
RETURN;
END;
' LANGUAGE plpgsql;
使用select count_em_all();叫它。
希望这对你有用。 保罗
其他回答
我通常不依赖于统计数据,尤其是在PostgreSQL中。
SELECT table_name, dsql2('select count(*) from '||table_name) as rownum
FROM information_schema.tables
WHERE table_type='BASE TABLE'
AND table_schema='livescreen'
ORDER BY 2 DESC;
CREATE OR REPLACE FUNCTION dsql2(i_text text)
RETURNS int AS
$BODY$
Declare
v_val int;
BEGIN
execute i_text into v_val;
return v_val;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
不确定bash中的答案对您来说是否可以接受,但FWIW…
PGCOMMAND=" psql -h localhost -U fred -d mydb -At -c \"
SELECT table_name
FROM information_schema.tables
WHERE table_type='BASE TABLE'
AND table_schema='public'
\""
TABLENAMES=$(export PGPASSWORD=test; eval "$PGCOMMAND")
for TABLENAME in $TABLENAMES; do
PGCOMMAND=" psql -h localhost -U fred -d mydb -At -c \"
SELECT '$TABLENAME',
count(*)
FROM $TABLENAME
\""
eval "$PGCOMMAND"
done
您可以使用此查询生成所有表名及其计数
select ' select '''|| tablename ||''', count(*) from ' || tablename ||'
union' from pg_tables where schemaname='public';
上述查询的结果将是
select 'dim_date', count(*) from dim_date union
select 'dim_store', count(*) from dim_store union
select 'dim_product', count(*) from dim_product union
select 'dim_employee', count(*) from dim_employee union
您需要删除最后一个联合符,并在末尾添加分号!!
select 'dim_date', count(*) from dim_date union
select 'dim_store', count(*) from dim_store union
select 'dim_product', count(*) from dim_product union
select 'dim_employee', count(*) from dim_employee **;**
跑! !
这对我很有效
SELECT schemaname,relname,n_live_tup FROM pg_stat_user_tables ORDER BY n_live_tup DESC;
下面的查询将给出每个表的行数和大小
选择table_schema, table_name, pg_relation_size('“' | | table_schema | |”“。”“| | table_name | |”“”)/ 1024/1024 size_MB, (xpath('/row/c/text()', query_to_xml(format('select count(*) AS c from %I.)%I', table_schema, table_name), false, true, ")))[1]::text::int AS rows_n 从information_schema.tables order by size_MB