KingbaseES普通表修改表结构请参考:KingbaseES变更表结构表重写问题
数据类型转换重写与不重写:
- varchar(x) 转换到 varchar(y) 当 y>=x,不需要重写。
- numeric(x,z) 转换到 numeric(y,z) 当 y>=x,或者不指定精度类型,不需要重写。
- numeric(x,c) 转换到 numeric(y,z) 当 y=x c>z,当numeric数据类型标度不一致时,需要重写。
- varbit(x) 转换到 varbit(y) 当 y>=x,不需要重写。
- timestamp(x) 转换到 timestamp(y) 当 y>=x,或者转换为timestamp,不需要重写。
- timestamptz(x) 转换到 timestamptz(y) 当 y>=x,或者转换为timestamptz,不需要重写。
- interval(x) 转换到 interval(y) 当 y>=x ,或者转换为interval,不需要重写。
- timestamp 转换到 text、varchar、varchar(n),char(n),需要重写。
- timestamp(x)转换到 text、varchar、varchar(n)、char(n),n>=x,需要重写。
- text 转换到 char、char(x)、varchar(n),需要重写。
- text 转换到 varchar,不需要重写。
- numeric(x) 转换到 numeric(y),y>=x,不需要重写。
- numeric(x) 转换到 numeric,不需要重写。
- numeric(x,y) 转换到 numeric,不需要重写。
一、普通表的修改:
普通表数据类型长度或者精度由小改大表不会重写,索引也不会重写。
test=# create table t01(id int,name varchar(10));
CREATE TABLE
test=# insert into t01 select generate_series(1,10),substr(md5(random()::text),1,10);
INSERT 0 10
test=# create index on t01 (name);
CREATE INDEX
test=# \d t01Table "public.t01"Column | Type | Collation | Nullable | Default
--------+----------------------------+-----------+----------+---------id | integer | | | name | character varying(10 char) | | |
Indexes:"t01_name_idx" btree (name)test=#
test=# select sys_relation_filenode('t01'),sys_relation_filenode('t01_name_idx');SYS_RELATION_FILENODE | SYS_RELATION_FILENODE
-----------------------+-----------------------289043 | 289046
(1 row)# 设置客户端消息级别client_min_messages=debug5
test=# set client_min_messages=debug5;# 修改t01表name字段长度varchar(10)为varchar(15)
test=# alter table t01 alter column name type varchar(15);
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: rehashing catalog cache id 68 for sys_recyclebin; 33 tups, 16 buckets
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428092/1/7
ALTER TABLEtest=# select sys_relation_filenode('t01'),sys_relation_filenode('t01_name_idx');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILENODE | SYS_RELATION_FILENODE
-----------------------+-----------------------289043 | 289046
(1 row)test=#
分区表修改表结构是否跟普通表一样?
二、分区表的修改:
分区表分区键无法修改数据类型,本测试只针对非分区键进行测试。
create table tb(id bigint,pdate date,info varchar2(10)) partition by range(pdate) INTERVAL ('1 MONTH'::INTERVAL)
(
PARTITION tb_p0 VALUES LESS THAN ('2023-01-01'),
PARTITION tb_p1 VALUES LESS THAN ('2023-02-01'),
PARTITION tb_p2 VALUES LESS THAN ('2023-03-01'),
PARTITION tb_p3 VALUES LESS THAN ('2023-04-01')
);
CREATE TABLE
insert into tb select generate_series(1,100),'2023-01-01'::date,substr(md5(random()::text),1,10);
INSERT 0 100
insert into tb select generate_series(101,200),'2023-02-01'::date,substr(md5(random()::text),1,10);
INSERT 0 100
insert into tb select generate_series(201,300),'2023-03-01'::date,substr(md5(random()::text),1,10);
INSERT 0 100
2.1.分区表非索引列数据类型的修改:
修改非索引列的类型:由小改大,表不会发生重写,索引自然也没有发生重写。
修改非索引列的类型:由大改小,遵循KingbaseES变更表结构表重写规则,表需要重写,索引也需要重写。
test=# set client_min_messages =debug5;
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0
SET
test=# select oid,relname from sys_class where relname='tb';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+---------289063 | tb
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p0';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289066 | tb_tb_p0
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p1';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289069 | tb_tb_p1
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p2';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289072 | tb_tb_p2
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p3';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289075 | tb_tb_p3
(1 row)# 修改tb分区表info列为varchar(20)
test=# alter table tb alter column info type varchar(20);
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428111/1/10
ALTER TABLEtest=# select oid,relname from sys_class where relname='tb';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+---------289063 | tb
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p0';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289066 | tb_tb_p0
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p1';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289069 | tb_tb_p1
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p2';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289072 | tb_tb_p2
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p3';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289075 | tb_tb_p3
(1 row)test=# alter table tb alter column info type varchar(30);
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428112/1/10
ALTER TABLE
test=# select oid,relname from sys_class where relname='tb';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+---------289063 | tb
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p0';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289066 | tb_tb_p0
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p1';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289069 | tb_tb_p1
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p2';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289072 | tb_tb_p2
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p3';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289075 | tb_tb_p3
(1 row)
分区表修改非索引列字段长度或者是精度由小变大,跟普通表一样,不需要重写。
2.2.分区表全局(GLOBAL)索引列数据类型的修改:
修改全局(GLOBAL)索引列的类型:由小改大,表不会发生重写,索引也没有发生重写。
修改全局(GLOBAL)索引列的类型:由大改小,遵循KingbaseES变更表结构表重写规则,表需要重写,索引也需要重写。
test=# \d+ tb Partitioned table "public.tb"Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
--------+----------------------------+-----------+----------+---------+----------+--------------+-------------id | bigint | | | | plain | | pdate | date | | | | plain | | info | character varying(10 char) | | not null | | extended | |
Partition key: RANGE (pdate)
Range interval: INTERVAL ('0-1'::pg_catalog.interval)
Partitions: tb_tb_p0 FOR VALUES FROM (MINVALUE) TO ('2023-01-01 00:00:00'),tb_tb_p1 FOR VALUES FROM ('2023-01-01 00:00:00') TO ('2023-02-01 00:00:00'),tb_tb_p2 FOR VALUES FROM ('2023-02-01 00:00:00') TO ('2023-03-01 00:00:00'),tb_tb_p3 FOR VALUES FROM ('2023-03-01 00:00:00') TO ('2023-04-01 00:00:00')# 添加主键
test=# alter table tb add constraint tb_pk primary key (info);
ALTER TABLE
test=# \d+ tbPartitioned table "public.tb"Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
--------+----------------------------+-----------+----------+---------+----------+--------------+-------------id | bigint | | | | plain | | pdate | date | | | | plain | | info | character varying(10 char) | | not null | | extended | |
Partition key: RANGE (pdate)
Range interval: INTERVAL ('0-1'::pg_catalog.interval)
Indexes:"tb_pk" PRIMARY KEY, btree (info) INCLUDE (tableoid) GLOBAL
Partitions: tb_tb_p0 FOR VALUES FROM (MINVALUE) TO ('2023-01-01 00:00:00'),tb_tb_p1 FOR VALUES FROM ('2023-01-01 00:00:00') TO ('2023-02-01 00:00:00'),tb_tb_p2 FOR VALUES FROM ('2023-02-01 00:00:00') TO ('2023-03-01 00:00:00'),tb_tb_p3 FOR VALUES FROM ('2023-03-01 00:00:00') TO ('2023-04-01 00:00:00')test=# select sys_relation_filepath('tb_pk'); SYS_RELATION_FILEPATH
-----------------------base/12176/289111
(1 row)test=# select oid,relname from sys_class where relname='tb'; OID | RELNAME
--------+---------289063 | tb
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p0';OID | RELNAME
--------+----------289066 | tb_tb_p0
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p1';OID | RELNAME
--------+----------289069 | tb_tb_p1
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p2';OID | RELNAME
--------+----------289072 | tb_tb_p2
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p3';OID | RELNAME
--------+----------289075 | tb_tb_p3
(1 row)test=# alter table tb alter info type varchar(20);
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: drop auto-cascades to index tb_pk
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428121/1/19
ALTER TABLE
test=# select sys_relation_filepath('tb_pk');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILEPATH
-----------------------base/12176/289111
(1 row)test=# select oid,relname from sys_class where relname='tb';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+---------289063 | tb
(1 row)test=# select oid,relname from sys_class where relname='tb_tb_p2';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+----------289072 | tb_tb_p2
(1 row)# 添加全局索引
test=# create unique index on tb(id,info) global;
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: building index "tb_id_info_idx" on table "tb" serially
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428122/1/4
CREATE INDEX
test=# \d+ tbPartitioned table "public.tb"Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
--------+----------------------------+-----------+----------+---------+----------+--------------+-------------id | bigint | | | | plain | | pdate | date | | | | plain | | info | character varying(20 char) | | not null | | extended | |
Partition key: RANGE (pdate)
Range interval: INTERVAL ('0-1'::pg_catalog.interval)
Indexes:"tb_pk" PRIMARY KEY, btree (info) INCLUDE (tableoid) GLOBAL "tb_id_info_idx" UNIQUE, btree (id, info) INCLUDE (tableoid) GLOBAL
Partitions: tb_tb_p0 FOR VALUES FROM (MINVALUE) TO ('2023-01-01 00:00:00'),tb_tb_p1 FOR VALUES FROM ('2023-01-01 00:00:00') TO ('2023-02-01 00:00:00'),tb_tb_p2 FOR VALUES FROM ('2023-02-01 00:00:00') TO ('2023-03-01 00:00:00'),tb_tb_p3 FOR VALUES FROM ('2023-03-01 00:00:00') TO ('2023-04-01 00:00:00')test=# select sys_relation_filepath('tb_pk');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILEPATH
-----------------------base/12176/289111
(1 row)test=# select sys_relation_filepath('tb_id_info_idx');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILEPATH
-----------------------base/12176/289115
(1 row)test=# alter table tb alter info type varchar(30);
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: drop auto-cascades to index tb_pk
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428123/1/27
ALTER TABLE
test=# select sys_relation_filepath('tb_pk');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILEPATH
-----------------------base/12176/289111
(1 row)test=# select sys_relation_filepath('tb_id_info_idx');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILEPATH
-----------------------base/12176/289115
(1 row)
分区表修改全局(GLOBAL)索引列字段长度或者是精度由小变大,跟普通表一样,不需要重写。
2.3.分区表本地(LOCAL)索引列数据类型的修改:
修改本地(LOCAL)索引列的类型:由小改大,表不会发生重写,索引发生重写。
修改本地(LOCAL)索引列的类型:由大改小,遵循KingbaseES变更表结构表重写规则,表需要重写,索引也需要重写。
test=# \d+ tbPartitioned table "public.tb"Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
--------+----------------------------+-----------+----------+---------+----------+--------------+-------------id | bigint | | | | plain | | pdate | date | | | | plain | | info | character varying(30 char) | | not null | | extended | |
Partition key: RANGE (pdate)
Range interval: INTERVAL ('0-1'::pg_catalog.interval)
Indexes:"tb_pk" PRIMARY KEY, btree (info) INCLUDE (tableoid) GLOBAL "tb_id_info_idx" UNIQUE, btree (id, info) INCLUDE (tableoid) GLOBAL
Partitions: tb_tb_p0 FOR VALUES FROM (MINVALUE) TO ('2023-01-01 00:00:00'),tb_tb_p1 FOR VALUES FROM ('2023-01-01 00:00:00') TO ('2023-02-01 00:00:00'),tb_tb_p2 FOR VALUES FROM ('2023-02-01 00:00:00') TO ('2023-03-01 00:00:00'),tb_tb_p3 FOR VALUES FROM ('2023-03-01 00:00:00') TO ('2023-04-01 00:00:00')# 创建本地索引
test=# create index on tb(pdate,info);
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: building index "tb_tb_p0_pdate_info_idx" on table "tb_tb_p0" serially
DEBUG: building index "tb_tb_p1_pdate_info_idx" on table "tb_tb_p1" serially
DEBUG: building index "tb_tb_p2_pdate_info_idx" on table "tb_tb_p2" serially
DEBUG: building index "tb_tb_p3_pdate_info_idx" on table "tb_tb_p3" serially
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428125/1/12
CREATE INDEX
test=# \d+ tbPartitioned table "public.tb"Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
--------+----------------------------+-----------+----------+---------+----------+--------------+-------------id | bigint | | | | plain | | pdate | date | | | | plain | | info | character varying(30 char) | | not null | | extended | |
Partition key: RANGE (pdate)
Range interval: INTERVAL ('0-1'::pg_catalog.interval)
Indexes:"tb_pk" PRIMARY KEY, btree (info) INCLUDE (tableoid) GLOBAL "tb_id_info_idx" UNIQUE, btree (id, info) INCLUDE (tableoid) GLOBAL "tb_pdate_info_idx" btree (pdate, info)
Partitions: tb_tb_p0 FOR VALUES FROM (MINVALUE) TO ('2023-01-01 00:00:00'),tb_tb_p1 FOR VALUES FROM ('2023-01-01 00:00:00') TO ('2023-02-01 00:00:00'),tb_tb_p2 FOR VALUES FROM ('2023-02-01 00:00:00') TO ('2023-03-01 00:00:00'),tb_tb_p3 FOR VALUES FROM ('2023-03-01 00:00:00') TO ('2023-04-01 00:00:00')test=# select sys_relation_filepath('tb_pk'),sys_relation_filepath('tb_id_info_idx');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILEPATH | SYS_RELATION_FILEPATH
-----------------------+-----------------------base/12176/289111 | base/12176/289115
(1 row)test=# select oid,relname from sys_class where relname='tb_pdate_info_idx';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+-------------------289119 | tb_pdate_info_idx
(1 row)# 修改本地索引依赖info列
test=# alter table tb alter info type varchar(40);
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: EventTriggerInvoke 267860
DEBUG: drop auto-cascades to index tb_tb_p0_pdate_info_idx
DEBUG: drop auto-cascades to index tb_tb_p1_pdate_info_idx
DEBUG: drop auto-cascades to index tb_tb_p2_pdate_info_idx
DEBUG: rehashing catalog cache id 68 for sys_recyclebin; 33 tups, 16 buckets
DEBUG: drop auto-cascades to index tb_tb_p3_pdate_info_idx
DEBUG: drop auto-cascades to index tb_pk
DEBUG: building index "tb_tb_p0_pdate_info_idx" on table "tb_tb_p0" serially
DEBUG: building index "tb_tb_p1_pdate_info_idx" on table "tb_tb_p1" serially
DEBUG: building index "tb_tb_p2_pdate_info_idx" on table "tb_tb_p2" serially
DEBUG: building index "tb_tb_p3_pdate_info_idx" on table "tb_tb_p3" serially
DEBUG: EventTriggerInvoke 13761
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 428127/1/51
ALTER TABLE
test=# select sys_relation_filepath('tb_pk'),sys_relation_filepath('tb_id_info_idx');
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0SYS_RELATION_FILEPATH | SYS_RELATION_FILEPATH
-----------------------+-----------------------base/12176/289111 | base/12176/289115
(1 row)test=# select oid,relname from sys_class where relname='tb_pdate_info_idx';
DEBUG: StartTransaction(1) name: unnamed; blockState: DEFAULT; state: INPROGRESS, xid/subid/cid: 0/1/0
DEBUG: CommitTransaction(1) name: unnamed; blockState: STARTED; state: INPROGRESS, xid/subid/cid: 0/1/0OID | RELNAME
--------+-------------------289127 | tb_pdate_info_idx
(1 row)test=#
分区表本地(LOCAL)索引列修改字段长度或者是精度由小变大,表、全局索引不需要重写,但是本地索引需要重写。
2.4.分区表修改表结构总结:
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分区表修改非索引列字段长度或者是精度由小变大,跟普通表一样,不需要重写。
-
分区表修改全局(GLOBAL)索引列字段长度或者是精度由小变大,跟普通表一样,不需要重写。
-
分区表本地(LOCAL)索引列修改字段长度或者是精度由小变大,表、全局索引不需要重写,但是本地索引需要重写。
三、分区表变更表结构的思考:
通过以上测试可知:分区表修改本地索引依赖字段长度或者标度会导致索引重写。
如果分区表数据量大、子分区多、字段列依赖的索引多,修改分区表(本地索引)列字段长度会发生如下问题:
修改字段长度由小到大:分区表所有的子表不会发生重写,但是索引会发生重写,索引越多阻塞时间越长。
目前想到的解决方法:删除被修改列依赖的所有本地索引,避免长时间的AccessExclusiveLock,修改完成后子表使用concurrently的方式创建。
修改字段长度由大到小:分区表所有的子表都会发生重写,只要表发生重写所有的索引都需要重写,此过程会导致业务不可用(影响太大)。
对分区表使用detach?分区表要求所有子分区的表结构必须跟父表一致,所有的子分区全部修改完成后再attach回去,跟直接改区别不大,可以避免业务中断。需要根据业务提前准备好脚本。