PGXC_GET_STAT_ALL_TABLES

PGXC_GET_STAT_ALL_TABLES displays information about insertion, update, and deletion operations on tables and the dirty page rate of tables.

Before running VACUUM FULL on a system catalog with a high dirty page rate, ensure that no user is performing operations on it. You are advised to run VACUUM FULL to tables (excluding system catalogs) whose dirty page rate exceeds 80% or run it based on service scenarios.

**Table 1** PGXC_GET_STAT_ALL_TABLES columns
Name	Type	Description
relid	oid	Table OID
relname	name	Table name
schemaname	name	Schema name of the table
n_tup_ins	numeric	Number of inserted tuples
n_tup_upd	numeric	Number of updated tuples
n_tup_del	numeric	Number of deleted tuples
n_live_tup	numeric	Number of live tuples
n_dead_tup	numeric	Number of dead tuples
dirty_page_rate	numeric(5,2)	Dirty page rate (%) of a table

GaussDB(DWS) also provides the pgxc_get_stat_dirty_tables(int dirty_percent, int n_tuples) and pgxc_get_stat_dirty_tables(int dirty_percent, int n_tuples, text schema) functions to quickly filter out tables whose dirty page rate is greater than dirty_percent, number of dead tuples is greater than n_tuples, and schema name is schema.

For details, see Other Functions.

Examples

Use the view PGXC_GET_STAT_ALL_TABLES to query the tables whose dirty page rate is greater than 30%.

    
         SELECT * FROM PGXC_GET_STAT_ALL_TABLES WHERE dirty_page_rate>30;
 relid |         relname         | schemaname | n_tup_ins | n_tup_upd | n_tup_del | n_live_tup | n_dead_tup | dirty_page_rate
-------+-------------------------+------------+-----------+-----------+-----------+------------+------------+-----------------
  2840 | pg_toast_2619           | pg_toast   |      7415 |         0 |      7415 |          0 |        291 |           88.00
  9001 | pgxc_class              | pg_catalog |     56331 |         3 |     56285 |         54 |        143 |           72.59
 53860 | reason                  | dbadmin    |         9 |        19 |         0 |          9 |         19 |           67.86
  9025 | pg_object               | pg_catalog |    112858 |   1179707 |    112619 |        246 |        429 |           63.56
  9015 | pgxc_node               | pg_catalog |        15 |        24 |         0 |         15 |         24 |           61.54
  2606 | pg_constraint           | pg_catalog |        78 |         0 |        42 |         36 |         42 |           53.85
  1260 | pg_authid               | pg_catalog |         6 |         6 |         0 |          6 |          6 |           50.00
(7 rows)

You can also use the pgxc_get_stat_dirty_tables function to query tables whose dirty page rate is greater than 10% and number of dirty data rows is greater than 1000.

    
         SELECT a.schemaname,a.relname,pg_size_pretty(pg_table_size(b.oid)),a.dirty_page_rate FROM pgxc_get_stat_dirty_tables(10,1000) a,pg_catalog.pg_class b WHERE a.relname = b.relname order by pg_table_size(b.oid) desc;
 schemaname |   relname    | pg_size_pretty | dirty_page_rate
------------+--------------+----------------+-----------------
 pg_catalog | pg_attribute | 2792 KB        |           12.09
 pg_catalog | pg_class     | 568 KB         |           15.36
 pg_catalog | pg_type      | 368 KB         |           12.17
(3 rows)