Re: toast tables - Mailing list pgsql-admin
From | Scott Mead |
---|---|
Subject | Re: toast tables |
Date | |
Msg-id | CAKq0gv+Qgwjy8FaDGb4otcOvP2WcsKx_EbOgq+Z7MXKG-AvJPQ@mail.gmail.com Whole thread Raw |
In response to | toast tables ("drum.lucas@gmail.com" <drum.lucas@gmail.com>) |
Responses |
Re: toast tables
|
List | pgsql-admin |
On Mon, May 9, 2016 at 6:59 PM, drum.lucas@gmail.com <drum.lucas@gmail.com> wrote:
Hi all,I'm currently using PostgreSQL 9.2 and my DB size is 2.2 TB..Running the query below;WITH schema_size AS (
SELECT
tab.table_catalog AS database_name,
tab.table_schema AS schema_name,
tab.table_name,
pg_total_relation_size(table_schema || '.' || tab.table_name) AS table_size_total,
pg_relation_size(table_schema || '.' || tab.table_name) AS table_size
FROM information_schema.tables tab
WHERE table_schema NOT IN ('pg_catalog', 'information_schema')
), pretty_size AS (
SELECT
database_name,
schema_name,
pg_database_size(database_name) AS database_size_bigint,
pg_size_pretty(pg_database_size(database_name)) AS database_size,
sum(table_size_total) AS schema_size_bigint_total,
pg_size_pretty(sum(table_size_total)) AS schema_size_total,
sum(table_size) AS schema_size_bigint,
pg_size_pretty(sum(table_size)) AS schema_size
FROM schema_size
GROUP BY database_name, schema_name
)
SELECT
database_name,
schema_name,
database_size,
schema_size_total,
schema_size,
((schema_size_bigint_total * 100) / database_size_bigint) AS perc_total,
((schema_size_bigint * 100) / database_size_bigint) AS perc
FROM pretty_sizeI get the following data:schema | schema_size_total | schema_size | perc_total | percgorfs | 1824 GB | 20 GB | 85.4308477608319514 | 0.94562882033477939710As you can see, the GORFS schema is 1.8 TB.That is all pg_Toast tables....I read the documentation [1] but actually I couldn't understand:Is there any way to get the size decreased ?The DB is in production, so I can't run the VACCUM FULL.Is there anything I can do?Is the pg_toast normal?
TOAST (The Oversized Attribute Storage Technique) is completely normal and automatic based on your datatypes.
Have you tried to estimate bloat?
/* WARNING: executed with a non-superuser role, the query inspect only tables you are granted to read.
* This query is compatible with PostgreSQL 9.0 and more
*/
SELECT current_database(), schemaname, tblname, bs*tblpages AS real_size,
(tblpages-est_tblpages)*bs AS extra_size,
CASE WHEN tblpages - est_tblpages > 0
THEN 100 * (tblpages - est_tblpages)/tblpages::float
ELSE 0
END AS extra_ratio, fillfactor, (tblpages-est_tblpages_ff)*bs AS bloat_size,
CASE WHEN tblpages - est_tblpages_ff > 0
THEN 100 * (tblpages - est_tblpages_ff)/tblpages::float
ELSE 0
END AS bloat_ratio, is_na
-- , (pst).free_percent + (pst).dead_tuple_percent AS real_frag
FROM (
SELECT ceil( reltuples / ( (bs-page_hdr)/tpl_size ) ) + ceil( toasttuples / 4 ) AS est_tblpages,
ceil( reltuples / ( (bs-page_hdr)*fillfactor/(tpl_size*100) ) ) + ceil( toasttuples / 4 ) AS est_tblpages_ff,
tblpages, fillfactor, bs, tblid, schemaname, tblname, heappages, toastpages, is_na
-- , stattuple.pgstattuple(tblid) AS pst
FROM (
SELECT
( 4 + tpl_hdr_size + tpl_data_size + (2*ma)
- CASE WHEN tpl_hdr_size%ma = 0 THEN ma ELSE tpl_hdr_size%ma END
- CASE WHEN ceil(tpl_data_size)::int%ma = 0 THEN ma ELSE ceil(tpl_data_size)::int%ma END
) AS tpl_size, bs - page_hdr AS size_per_block, (heappages + toastpages) AS tblpages, heappages,
toastpages, reltuples, toasttuples, bs, page_hdr, tblid, schemaname, tblname, fillfactor, is_na
FROM (
SELECT
tbl.oid AS tblid, ns.nspname AS schemaname, tbl.relname AS tblname, tbl.reltuples,
tbl.relpages AS heappages, coalesce(toast.relpages, 0) AS toastpages,
coalesce(toast.reltuples, 0) AS toasttuples,
coalesce(substring(
array_to_string(tbl.reloptions, ' ')
FROM '%fillfactor=#"__#"%' FOR '#')::smallint, 100) AS fillfactor,
current_setting('block_size')::numeric AS bs,
CASE WHEN version()~'mingw32' OR version()~'64-bit|x86_64|ppc64|ia64|amd64' THEN 8 ELSE 4 END AS ma,
24 AS page_hdr,
23 + CASE WHEN MAX(coalesce(null_frac,0)) > 0 THEN ( 7 + count(*) ) / 8 ELSE 0::int END
+ CASE WHEN tbl.relhasoids THEN 4 ELSE 0 END AS tpl_hdr_size,
sum( (1-coalesce(s.null_frac, 0)) * coalesce(s.avg_width, 1024) ) AS tpl_data_size,
bool_or(att.atttypid = 'pg_catalog.name'::regtype) AS is_na
FROM pg_attribute AS att
JOIN pg_class AS tbl ON att.attrelid = tbl.oid
JOIN pg_namespace AS ns ON ns.oid = tbl.relnamespace
JOIN pg_stats AS s ON s.schemaname=ns.nspname
AND s.tablename = tbl.relname AND s.inherited=false AND s.attname=att.attname
LEFT JOIN pg_class AS toast ON tbl.reltoastrelid = toast.oid
WHERE att.attnum > 0 AND NOT att.attisdropped
AND tbl.relkind = 'r'
GROUP BY 1,2,3,4,5,6,7,8,9,10, tbl.relhasoids
ORDER BY 2,3
) AS s
) AS s2
) AS s3
-- WHERE NOT is_na
-- AND tblpages*((pst).free_percent + (pst).dead_tuple_percent)::float4/100 >= 1 pgsql-admin by date: