pg_repack bloat 处理测试初步-阿里云开发者社区

一、软件安装

1.软件需求：

postgresql-9.5.2.tar.gz

pg_repack-1.3.4.zip

2.安装pg_repack

[root@localhost pg_repack-1.3.4]# export PATH=/opt/pgsql/9.5.2/bin:$PATH

[root@localhost pg_repack-1.3.4]# export LD_LIBRARY_PATH=/opt/pgsql/9.5.2/lib

[root@localhost pg_repack-1.3.4]# export MANPATH=/opt/pgsql/9.5.2/share/man:$MANPATH

[root@localhost pg_repack-1.3.4]# make

make[1]: Entering directory `/home/soft/pg_repack-1.3.4/bin'

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -O2 -I/opt/pgsql/9.5.2/include -DREPACK_VERSION=1.3.4 -I. -I./ -I/opt/pgsql/9.5.2/include/server -I/opt/pgsql/9.5.2/include/internal -D_GNU_SOURCE -c -o pg_repack.o pg_repack.c

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -O2 pg_repack.o pgut/pgut.o pgut/pgut-fe.o -L/opt/pgsql/9.5.2/lib -lpq -L/opt/pgsql/9.5.2/lib -Wl,--as-needed -Wl,-rpath,'/opt/pgsql/9.5.2/lib',--enable-new-dtags -lpgcommon -lpgport -lz -lreadline -lrt -lcrypt -ldl -lm -o pg_repack

make[1]: Leaving directory `/home/soft/pg_repack-1.3.4/bin'

make[1]: Entering directory `/home/soft/pg_repack-1.3.4/lib'

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -O2 -fpic -DREPACK_VERSION=1.3.4 -I. -I./ -I/opt/pgsql/9.5.2/include/server -I/opt/pgsql/9.5.2/include/internal -D_GNU_SOURCE -c -o repack.o repack.c

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -O2 -fpic -DREPACK_VERSION=1.3.4 -I. -I./ -I/opt/pgsql/9.5.2/include/server -I/opt/pgsql/9.5.2/include/internal -D_GNU_SOURCE -c -o pgut/pgut-be.o pgut/pgut-be.c

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -O2 -fpic -DREPACK_VERSION=1.3.4 -I. -I./ -I/opt/pgsql/9.5.2/include/server -I/opt/pgsql/9.5.2/include/internal -D_GNU_SOURCE -c -o pgut/pgut-spi.o pgut/pgut-spi.c

( echo '{ global:'; gawk '/^[^#]/ {printf "%s;\n",$1}' exports.txt; echo ' local: *; };' ) >exports.list

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -O2 -fpic -shared -Wl,--version-script=exports.list -o pg_repack.so repack.o pgut/pgut-be.o pgut/pgut-spi.o -L/opt/pgsql/9.5.2/lib -Wl,--as-needed -Wl,-rpath,'/opt/pgsql/9.5.2/lib',--enable-new-dtags

sed 's,REPACK_VERSION,1.3.4,g' pg_repack.sql.in > pg_repack--1.3.4.sql;

sed 's,REPACK_VERSION,1.3.4,g' pg_repack.control.in > pg_repack.control

make[1]: Leaving directory `/home/soft/pg_repack-1.3.4/lib'

make[1]: Entering directory `/home/soft/pg_repack-1.3.4/regress'

make[1]: Nothing to be done for `all'.

make[1]: Leaving directory `/home/soft/pg_repack-1.3.4/regress'

[root@localhost pg_repack-1.3.4]# make install

make[1]: Entering directory `/home/soft/pg_repack-1.3.4/bin'

/bin/mkdir -p '/opt/pgsql/9.5.2/bin'

/usr/bin/install -c pg_repack '/opt/pgsql/9.5.2/bin'

make[1]: Leaving directory `/home/soft/pg_repack-1.3.4/bin'

make[1]: Entering directory `/home/soft/pg_repack-1.3.4/lib'

/bin/mkdir -p '/opt/pgsql/9.5.2/lib'

/bin/mkdir -p '/opt/pgsql/9.5.2/share/extension'

/usr/bin/install -c -m 755 pg_repack.so '/opt/pgsql/9.5.2/lib/pg_repack.so'

/usr/bin/install -c -m 644 .//pg_repack.control '/opt/pgsql/9.5.2/share/extension/'

/usr/bin/install -c -m 644 pg_repack--1.3.4.sql pg_repack.control '/opt/pgsql/9.5.2/share/extension/'

make[1]: Leaving directory `/home/soft/pg_repack-1.3.4/lib'

make[1]: Entering directory `/home/soft/pg_repack-1.3.4/regress'

make[1]: Nothing to be done for `install'.

make[1]: Leaving directory `/home/soft/pg_repack-1.3.4/regress'

[root@localhost pg_repack-1.3.4]#

3.创建初始环境

[postgres@localhost ~]$ createdb bloatdb

[postgres@localhost ~]$ psql -d bloatdb -c "create extension pgstattuple;"

CREATE EXTENSION

[postgres@localhost ~]$ psql -d bloatdb -c "CREATE EXTENSION pg_repack;"

CREATE EXTENSION

[postgres@localhost ~]$

$ psql bloatdb

psql (9.5.2)

Type "help" for help.

bloatdb=# \dx

List of installed extensions

Name | Version | Schema | Description

-------------+---------+------------+--------------------------------------------------------------

pg_repack | 1.3.4 | public | Reorganize tables in PostgreSQL databases with minimal locks

pgstattuple | 1.3 | public | show tuple-level statistics

plpgsql | 1.0 | pg_catalog | PL/pgSQL procedural language

(3 rows)

二、静态（无活跃交易）膨胀整理测试

1.处理表tbl指定索引

1).准备环境

bloatdb=# create table tbl(id int primary key, first varchar(20),second varchar(20));

CREATE TABLE

bloatdb=# create index idx_tbl_first on tbl (first);

CREATE INDEX

bloatdb=# create index idx_tbl_second on tbl (second);

CREATE INDEX

bloatdb=# SELECT count(*) FROM tbl;

count

-------

(1 row)

bloatdb=# SELECT pg_size_pretty(pg_total_relation_size('tbl'));

pg_size_pretty

----------------

24 kB

(1 row)

bloatdb=# INSERT INTO tbl VALUES(generate_series(1,10000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

INSERT 0 10000

bloatdb=# SELECT count(*) FROM tbl;

count

-------

10000

(1 row)

bloatdb=# SELECT pg_size_pretty(pg_total_relation_size('tbl'));

pg_size_pretty

----------------

1584 kB

(1 row)

bloatdb=#

更新列

bloatdb=# UPDATE tbl SET first= 'updated-001';

UPDATE 10000

bloatdb=# SELECT count(*) FROM tbl;

count

-------

10000

(1 row)

bloatdb=# SELECT pg_size_pretty(pg_total_relation_size('tbl'));

pg_size_pretty

----------------

3376 kB

(1 row)

bloatdb=#

2).查询膨胀率

建立膨胀统计表

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" --create_stats_table

膨胀统计

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_second.......................................................(52.69%) 417 kB wasted

2. public.idx_tbl_first........................................................(52.64%) 413 kB wasted

3. public.tbl_pkey.............................................................(57.79%) 388 kB wasted

[postgres@localhost ~]$

3).处理膨胀

指定数据库的特定索引

[postgres@localhost ~]$ pg_repack -d bloatdb --index idx_tbl_first

INFO: repacking index "public"."idx_tbl_first"

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_second.......................................................(52.69%) 417 kB wasted

2. public.tbl_pkey.............................................................(57.79%) 388 kB wasted

3. public.idx_tbl_first.....................................................(0.93%) 3121 bytes wasted

[postgres@localhost ~]$

2.处理表tbl所有索引

1).准备环境

bloatdb=# update tbl set second='chris';

UPDATE 10000

bloatdb=# SELECT count(*) FROM tbl;

count

-------

10000

(1 row)

bloatdb=# SELECT pg_size_pretty(pg_total_relation_size('tbl'));

pg_size_pretty

----------------

3600 kB

(1 row)

bloatdb=#

bloatdb=# update tbl set first='chris';

UPDATE 10000

bloatdb=# SELECT count(*) FROM tbl;

count

-------

10000

(1 row)

bloatdb=# SELECT pg_size_pretty(pg_total_relation_size('tbl'));

pg_size_pretty

----------------

4176 kB

(1 row)

bloatdb=#

2).检查膨胀

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_second.......................................................(59.94%) 820 kB wasted

2. public.idx_tbl_first........................................................(40.94%) 409 kB wasted

3. public.tbl_pkey.............................................................(28.73%) 193 kB wasted

[postgres@localhost ~]$

3).处理tbl表所有索引膨胀

[postgres@localhost ~]$ pg_repack -d bloatdb --table tbl --only-indexes

INFO: repacking indexes of "tbl"

INFO: repacking index "public"."idx_tbl_first"

INFO: repacking index "public"."idx_tbl_second"

INFO: repacking index "public"."tbl_pkey"

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_first.....................................................(1.23%) 3028 bytes wasted

2. public.idx_tbl_second....................................................(1.23%) 3028 bytes wasted

3. public.tbl_pkey..........................................................(1.23%) 3028 bytes wasted

[postgres@localhost ~]$

3.处理tbl数据和索引膨胀

1).索引膨胀

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_first.........................................................(57.87%) 49 MB wasted

2. public.idx_tbl_second........................................................(39.29%) 34 MB wasted

3. public.tbl_pkey..............................................................(51.22%) 26 MB wasted

2).处理膨胀online VACUUM FULL 数据库bloatdb表tbl(数据和索引)

[postgres@localhost ~]$ pg_repack --no-order --table tbl -d bloatdb

INFO: repacking table "tbl"

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.tbl_pkey..............................................................(0.0%) 0 bytes wasted

2. public.idx_tbl_second........................................................(0.0%) 0 bytes wasted

3. public.idx_tbl_first.........................................................(0.0%) 0 bytes wasted

[postgres@localhost ~]$

三、动态(有交易发生时)膨胀处理

1.整个表做膨胀处理

1).初始条件

-- clear table data

bloatdb=# select * from tbl;

id | first | second

----+-------+--------

(0 rows)

bloatdb=#

bloatdb=# INSERT INTO tbl VALUES(generate_series(1,100000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

INSERT 0 100000

bloatdb=# UPDATE tbl SET first= 'updated-001';

UPDATE 100000

bloatdb=#

-- check bloat

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_second........................................................(67.26%) 17 MB wasted

2. public.idx_tbl_first.........................................................(67.46%) 17 MB wasted

3. public.tbl_pkey............................................................(63.91%) 9832 kB wasted

[postgres@localhost ~]$

2).大量插入数据同时做膨胀处理

statement_timeout=0, 视情况调整：maintenance_work_mem，wal_keep_segments(streaming,SSD<2000>)

先插入数据，过程中处理膨胀加上-T参数值为3600.

-- session 1：insert data

bloatdb=# INSERT INTO tbl VALUES(generate_series(100001,3000000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

光标闪烁

-- session 2：repack during insert

$ pg_repack -d bloatdb --no-order --table tbl --wait-timeout=3600

INFO: repacking table "tbl"

光标闪烁

############################## args: -j ###########################################

如果使用--table指定多个table时，会依次处理每个指定的表。如果整理使用-j参数，则pg_repack，在创建临时表索引时会启动多个后台进程并行创建索引，一般每建立一个索引都需要启动一个后台进程，直到min(j,tbl_idx_number<表中总的索引数>)数量的worker被创建完成。当指定j数量小于索引数量时，一个索引创建完成时，空闲的work会自动被分派去建立剩余索引。当指定j数量大于索引数量时，一次性分派索引总数个work来执行索引创建任务。

$ pg_repack -j 10 --no-order -d bloatdb --table tbl --wait-timeout=3600

NOTICE: Setting up workers.conns

INFO: repacking table "tbl"

LOG: Initial worker 0 to build index: CREATE UNIQUE INDEX index_22025 ON repack.table_22022 USING btree (id)

LOG: Initial worker 1 to build index: CREATE INDEX index_22027 ON repack.table_22022 USING btree (first)

LOG: Initial worker 2 to build index: CREATE INDEX index_22028 ON repack.table_22022 USING btree (second)

LOG: Command finished in worker 0: CREATE UNIQUE INDEX index_22025 ON repack.table_22022 USING btree (id)

LOG: Command finished in worker 1: CREATE INDEX index_22027 ON repack.table_22022 USING btree (first)

LOG: Command finished in worker 2: CREATE INDEX index_22028 ON repack.table_22022 USING btree (second)

指定多个表的情况，j < idx_numbers

$ pg_repack -j 2 --no-order -d bloatdb --table tbl -t tbl01 --wait-timeout=3600

NOTICE: Setting up workers.conns

INFO: repacking table "tbl"

LOG: Initial worker 0 to build index: CREATE UNIQUE INDEX index_22025 ON repack.table_22022 USING btree (id)

LOG: Initial worker 1 to build index: CREATE INDEX index_22027 ON repack.table_22022 USING btree (first)

LOG: Command finished in worker 0: CREATE UNIQUE INDEX index_22025 ON repack.table_22022 USING btree (id)

LOG: Assigning worker 0 to build index #2: CREATE INDEX index_22028 ON repack.table_22022 USING btree (second)

LOG: Command finished in worker 1: CREATE INDEX index_22027 ON repack.table_22022 USING btree (first)

LOG: Command finished in worker 0: CREATE INDEX index_22028 ON repack.table_22022 USING btree (second)

(处理过程中有长事务，会等待事务完成)

NOTICE: Waiting for 1 transactions to finish. First PID: 10426

INFO: repacking table "tbl01"

LOG: Initial worker 0 to build index: CREATE UNIQUE INDEX index_22065 ON repack.table_22062 USING btree (id)

LOG: Initial worker 1 to build index: CREATE INDEX index_22067 ON repack.table_22062 USING btree (first)

LOG: Command finished in worker 0: CREATE UNIQUE INDEX index_22065 ON repack.table_22062 USING btree (id)

LOG: Assigning worker 0 to build index #2: CREATE INDEX index_22068 ON repack.table_22062 USING btree (second)

LOG: Command finished in worker 1: CREATE INDEX index_22067 ON repack.table_22062 USING btree (first)

LOG: Command finished in worker 0: CREATE INDEX index_22068 ON repack.table_22062 USING btree (second)

##################################################################################

--session 1 finish insert

bloatdb=# INSERT INTO tbl VALUES(generate_series(100001,3000000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

INSERT 0 2900000

bloatdb=#

-- session 2： finish repack

[postgres@localhost ~]$ pg_repack -d bloatdb --no-order --table tbl --wait-timeout=3600

INFO: repacking table "tbl"

-- session 2：膨胀检查

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.tbl_pkey..............................................................(0.0%) 0 bytes wasted

2. public.idx_tbl_second........................................................(0.0%) 0 bytes wasted

3. public.idx_tbl_first.........................................................(0.0%) 0 bytes wasted

[postgres@localhost ~]$

-- session 1：数据检查

bloatdb=# select count(*) from tbl ;

count

---------

3000000

(1 row)

bloatdb=#

2.指定tbl表所有索引膨胀处理

如果tbl表有多个索引情况下，默认处理方式，一个索引接着一个索引做膨胀处理即使指定了-j参数大于1。

1).准备数据

--session 1： insert data

bloatdb=# delete FROM tbl;

DELETE 3000000

bloatdb=# INSERT INTO tbl VALUES(generate_series(1,100000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

INSERT 0 100000

bloatdb=# update tbl set first='chris';

UPDATE 100000

bloatdb=#

-- session 2：check bloat

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.tbl_pkey..............................................................(41.14%) 28 MB wasted

2. public.idx_tbl_second.......................................................(4.32%) 4471 kB wasted

3. public.idx_tbl_first........................................................(2.96%) 2889 kB wasted

[postgres@localhost ~]$

2).online insert and repack

--session 1： insert large data

bloatdb=# INSERT INTO tbl VALUES(generate_series(100001,3000000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

光标闪烁

-- session 2：process bloat，during session 1 inert large data

[postgres@localhost ~]$ pg_repack -d bloatdb --table tbl --only-indexes --wait-timeout=3600

INFO: repacking indexes of "tbl"

INFO: repacking index "public"."idx_tbl_first"

INFO: repacking index "public"."idx_tbl_second"

光标闪烁

--session 1：insert finish

bloatdb=# INSERT INTO tbl VALUES(generate_series(100001,3000000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

INSERT 0 2900000

bloatdb=#

--session 2：repack finish

[postgres@localhost ~]$ pg_repack -d bloatdb --table tbl --only-indexes -T 3600

INFO: repacking indexes of "tbl"

INFO: repacking index "public"."idx_tbl_first"

INFO: repacking index "public"."idx_tbl_second"

INFO: repacking index "public"."tbl_pkey"

3) check table data and index bloat

--session 2：check bloat

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.tbl_pkey..............................................................(0.0%) 0 bytes wasted

2. public.idx_tbl_first.........................................................(0.0%) 0 bytes wasted

3. public.idx_tbl_second........................................................(0.0%) 0 bytes wasted

[postgres@localhost ~]$

--session 1：check table data

bloatdb=# select count(*) from tbl;

count

---------

3000000

(1 row)

bloatdb=#

3.指定tbl表指定索引膨胀处理

注意：--index(默认使用concurrently方式创建指定索引)，无法与--only-indexes选项同时使用。

[postgres@localhost ~]$ pg_repack -d bloatdb --index idx_tbl_first --only-indexes

ERROR: cannot specify --index (-i) and --only-indexes (-x)

1).准备数据

-- read data

bloatdb=# delete FROM tbl;

DELETE 3000000

bloatdb=# INSERT INTO tbl VALUES(generate_series(1,100000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

INSERT 0 100000

bloatdb=# update tbl set first='chris';

UPDATE 100000

bloatdb=#

-- check bloat

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_second........................................................(47.57%) 97 MB wasted

2. public.tbl_pkey.............................................................(9.44%) 7206 kB wasted

3. public.idx_tbl_first........................................................(3.11%) 3040 kB wasted

[postgres@localhost ~]$

2).online insert and repack

--session 1： insert large data

bloatdb=# INSERT INTO tbl VALUES(generate_series(100001,3000000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

光标闪烁

-- session 2：process bloat，during session 1 inert large data

[postgres@localhost ~]$ pg_repack -d bloatdb --index idx_tbl_second --wait-timeout=3600

INFO: repacking index "public"."idx_tbl_second"

光标闪烁

--session 1：insert finish

bloatdb=# INSERT INTO tbl VALUES(generate_series(100001,3000000), 'first'||(random()*(10^3))::integer, 'second'||(random()*(10^3))::integer);

INSERT 0 2900000

bloatdb=#

--session 2：repack finish

[postgres@localhost ~]$ pg_repack -d bloatdb --index idx_tbl_second --wait-timeout=3600

INFO: repacking index "public"."idx_tbl_second"

[postgres@localhost ~]$

3) check table data and index bloat

--session 2：check bloat

[postgres@localhost ~]$ /home/soft/pg_bloat_check-master/pg_bloat_check.py -c "dbname=bloatdb" -t tbl

1. public.idx_tbl_first........................................................(50.77%) 102 MB wasted

2. public.tbl_pkey...............................................................(47.6%) 65 MB wasted

3. public.idx_tbl_second........................................................(0.0%) 0 bytes wasted

[postgres@localhost ~]$

--session 1：check table data

bloatdb=# select count(*) from tbl;

count

---------

3000000

(1 row)

bloatdb=#

测试结论：

一般同等条件下，索引比数据更容易膨胀。
在磁盘空间较紧张的情况下，建议一条接着一条索引处理。
一般bloat处理所需磁盘空闲空间是对象size的2倍，所以处理前必须先关注空闲磁盘空间大小。
注意pg_repack版本对Pg版本的支持情况，9.6截至2016-11-26仍未支持，详见http://pgxn.org/dist/pg_repack/doc/pg_repack.html#Releases。
处理存在在线交易的表或者索引对象的bloat时，注意设置超时参数--wait-timeout，一般设置为1800或3600（特别感谢李海龙建议）。