Description：

pg_reorg is an utility program toreorganize tables in PostgreSQL databases. Unlike clusterdb, it doesn‘t blockany selections and updates during reorganization. You can choose one of thefollowing methods to reorganize.

99549.960 ms

 

3、限制

Temp tables

pg_reorg cannot reorganize temp tables.

 

GiST indexes

pg_reorg cannot reorganize tables usingGiST indexes.

 

DDL commands

You cannot do DDL commands except VACUUMand ANALYZE during pg_reorg. In many cases pg_reorg will fail and rollback collectly,but there are some cases which may result in data-corruption .

 

TRUNCATE

TRUNCATE islost. Deleted rows still exist after pg_reorg.

CREATE INDEX

It causes indexcorruptions.

ALTER TABLE ... ADD COLUMN

It causes lostof data. Newly added columns are initialized with NULLs.

ALTER TABLE ... ALTER COLUMN TYPE

It causes datacorruptions.

ALTER TABLE ... SET TABLESPACE

It causes datacorruptions by wrong relfilenode.

 

 

注意：

1. 重组过程中会增大I/O压力，执行重组时应避开系统繁忙的时间段;

2. 重组过程中需要创建一些临时对象，所以执行重组时应确保有足够的磁盘空间。

    

附

LOG: statement: SET statement_timeout = 0

LOG: statement: SET search_path = pg_catalog, pg_temp, public

LOG: statement: SET client_min_messages = warning

LOG: execute <unnamed>: SELECT * FROM reorg.tables WHERE relid =$1::regclass

DETAIL: parameters: $1 = ‘t1‘

LOG: statement: BEGIN ISOLATION LEVEL READ COMMITTED

LOG: statement: SET LOCAL statement_timeout = 100

LOG: statement: LOCK TABLE t1 IN ACCESS EXCLUSIVE MODE

LOG: statement: RESET statement_timeout

LOG: execute <unnamed>: SELECT reorg.conflicted_triggers($1)

DETAIL: parameters: $1 = ‘16843‘

LOG: statement: CREATE TYPE reorg.pk_16843 AS (id integer)

LOG: statement: CREATE TABLE reorg.log_16843 (id bigserial PRIMARY KEY, pkreorg.pk_16843, row t1)

LOG: statement: CREATE TRIGGER z_reorg_trigger BEFORE INSERT OR DELETE ORUPDATE ON t1 FOR EACH ROW EXECUTE PROCEDURE reorg.reorg_trigger(‘INSERT INTOreorg.log_16843(pk, row) VALUES( CASE WHEN $1 IS NULL THEN NULL ELSE(ROW($1.id)::reorg.pk_16843) END, $2)‘)

LOG: statement: SELECT reorg.disable_autovacuum(‘reorg.log_16843‘)

LOG: statement: COMMIT

LOG: statement: BEGIN ISOLATION LEVEL SERIALIZABLE

LOG: statement: SELECT set_config(‘work_mem‘,current_setting(‘maintenance_work_mem‘), true)

LOG: statement: SET LOCAL synchronize_seqscans = off

LOG: statement: SELECT reorg.array_accum(virtualtransaction) FROM pg_locksWHERE locktype = ‘virtualxid‘ AND pid <> pg_backend_pid() AND(virtualxid, virtualtransaction) <> (‘1/1‘, ‘-1/0‘)

LOG: statement: DELETE FROM reorg.log_16843

LOG: statement: CREATE TABLE reorg.table_16843 WITH (oids=false) TABLESPACEpg_default AS SELECT id,name FROM ONLY t1

LOG: statement: SELECT reorg.disable_autovacuum(‘reorg.table_16843‘)

LOG: statement: COMMIT

LOG: execute <unnamed>: SELECT indexrelid,reorg.reorg_indexdef(indexrelid, indrelid), indisvalid,pg_get_indexdef(indexrelid) FROM pg_index WHERE indrelid = $1

DETAIL: parameters: $1 = ‘16843‘

LOG: statement: CREATE UNIQUE INDEX index_16849 ON reorg.table_16843 USINGbtree (id)

LOG: execute <unnamed>: SELECT reorg.reorg_apply($1, $2, $3, $4, $5,$6)

DETAIL: parameters: $1 = ‘SELECT * FROM reorg.log_16843 ORDER BY id LIMIT $1‘,$2 = ‘INSERT INTO reorg.table_16843 VALUES ($1.*)‘, $3 = ‘DELETE FROMreorg.table_16843 WHERE (id) = ($1.id)‘, $4 = ‘UPDATE reorg.table_16843 SET(id, name) = ($2.id, $2.name) WHERE (id) = ($1.id)‘, $5 = ‘DELETE FROMreorg.log_16843 WHERE id = $1‘, $6 = ‘1000‘

LOG: execute <unnamed>: SELECT pid FROM pg_locks WHERE locktype =‘virtualxid‘ AND pid <> pg_backend_pid() AND virtualtransaction = ANY($1)

DETAIL: parameters: $1 = ‘{}‘

LOG: statement: BEGIN ISOLATION LEVEL READ COMMITTED

LOG: statement: SET LOCAL statement_timeout = 100

LOG: statement: LOCK TABLE t1 IN ACCESS EXCLUSIVE MODE

LOG: statement: RESET statement_timeout

LOG: execute <unnamed>: SELECT reorg.reorg_apply($1, $2, $3, $4, $5,$6)

DETAIL: parameters: $1 = ‘SELECT * FROM reorg.log_16843 ORDER BY id LIMIT $1‘,$2 = ‘INSERT INTO reorg.table_16843 VALUES ($1.*)‘, $3 = ‘DELETE FROMreorg.table_16843 WHERE (id) = ($1.id)‘, $4 = ‘UPDATE reorg.table_16843 SET(id, name) = ($2.id, $2.name) WHERE (id) = ($1.id)‘, $5 = ‘DELETE FROMreorg.log_16843 WHERE id = $1‘, $6 = ‘0‘

LOG: execute <unnamed>: SELECT reorg.reorg_swap($1)

DETAIL: parameters: $1 = ‘16843‘

LOG: statement: COMMIT

LOG: statement: BEGIN ISOLATION LEVEL READ COMMITTED

LOG: execute <unnamed>: SELECT reorg.reorg_drop($1)

DETAIL: parameters: $1 = ‘16843‘

LOG: statement: COMMIT

LOG: statement: BEGIN ISOLATION LEVEL READ COMMITTED

LOG: statement: ANALYZE t1

LOG: statement: COMMIT