Oracle 分區(qū)表之在線重定義
一、介紹
「DBMS_REDEFINITION(在線重定義):」
- 「支持的數(shù)據(jù)庫(kù)版本」:Oracle Database - Enterprise Edition - Version 9.2.0.4 and later
- 在線重定義是通過(guò) 「物化視圖」 實(shí)現(xiàn)的。
「使用在線重定義的一些限制條件」:
- 必須有足夠的表空間來(lái)容納表的兩倍數(shù)據(jù)量。
- 主鍵列不能被修改。
- 表必須有主鍵。
- 必須在同一個(gè)用戶下進(jìn)行在線重定義。
- SYS和SYSTEM用戶下的表無(wú)法進(jìn)行在線重定義。
- 在線重定義無(wú)法采用nologging。
- 如果中間表有新增列,則不能有NOT NULL約束
「DBMS_REDEFINITION包:」
- ABSORT_REDEF_TABLE:清理重定義的錯(cuò)誤和中止重定義;
- CAN_REDEF_TABLE:檢查表是否可以進(jìn)行重定義,存儲(chǔ)過(guò)程執(zhí)行成功代表可以進(jìn)行重定義;
- COPY_TABLE_DEPENDENTS:同步索引和依賴的對(duì)象(包括索引、約束、觸發(fā)器、權(quán)限等);
- FINISH_REDEF_TABLE:完成在線重定義;
- REGISTER_DEPENDENTS_OBJECTS:注冊(cè)依賴的對(duì)象,如索引、約束、觸發(fā)器等;
- START_REDEF_TABLE:開始在線重定義;
- SYNC_INTERIM_TABLE:增量同步數(shù)據(jù);
- UNREGISTER_DEPENDENT_OBJECT:不注冊(cè)依賴的對(duì)象,如索引、約束、觸發(fā)器等;
二、實(shí)戰(zhàn)
1、構(gòu)建測(cè)試數(shù)據(jù)創(chuàng)建測(cè)試表空間和用戶:
- sqlplus / as sysdba
- create tablespace PAR;
- create user par identified by par;
- grant dba to par;
創(chuàng)建測(cè)試表:
- sqlplus par/par
- create table lucifer(
- id number(8) PRIMARY KEY,
- name varchar2(20) not null,
- par_date date)
- tablespace PAR;
- comment on table lucifer is 'lucifer表';
- comment on column lucifer.name is '姓名';
- comment on column lucifer.par_date is '分區(qū)日期';
- create index id_name on lucifer(name) tablespace par;
插入測(cè)試數(shù)據(jù):
- sqlplus par/par
- begin
- for i in 0 .. 24 loop
- insert into lucifer values
- (i,
- 'lcuifer_' || i,
- add_months(to_date('2021-1-1', 'yyyy-mm-dd'), i));
- end loop;
- commit;
- end;
- /
可以看到,測(cè)試數(shù)據(jù)已經(jīng)構(gòu)建完成,接下來(lái)開始實(shí)戰(zhàn)操作。
2、查看是否能夠重定義
需提前確認(rèn)表是否有主鍵,表空間是否足夠:
- sqlplus / as sysdba
- ##查看主鍵
- select cu.* from user_cons_columns cu, user_constraints au where cu.constraint_name = au.constraint_name and au.constraint_type = 'P' and au.table_name = 'LUCIFER';
確認(rèn)是否可以重定義,沒(méi)有主鍵用 rowid:
- sqlplus / as sysdba
- exec dbms_redefinition.can_redef_table('PAR', 'LUCIFER');
執(zhí)行沒(méi)有報(bào)錯(cuò)代表可以進(jìn)行表的在線重定義。
3、創(chuàng)建中間表(分區(qū)表結(jié)構(gòu))
通過(guò)PL/SQL包一鍵生成分區(qū)表結(jié)構(gòu):
- sqlplus par/par
- BEGIN
- ctas_par(p_tab => 'lucifer',
- p_part_colum => 'par_date',
- p_part_nums => 24,
- p_tablespace => 'par');
- END;
- /
創(chuàng)建中間分區(qū)表 lucifer_par:
- create table lucifer_par
- (
- id NUMBER(8),
- name VARCHAR2(20),
- par_date DATE
- )
- partition BY RANGE(par_date)(
- partition lucifer_P202101 values less than (TO_DATE(' 2021-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202102 values less than (TO_DATE(' 2021-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202103 values less than (TO_DATE(' 2021-04-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202104 values less than (TO_DATE(' 2021-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202105 values less than (TO_DATE(' 2021-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202106 values less than (TO_DATE(' 2021-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202107 values less than (TO_DATE(' 2021-08-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202108 values less than (TO_DATE(' 2021-09-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202109 values less than (TO_DATE(' 2021-10-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202110 values less than (TO_DATE(' 2021-11-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202111 values less than (TO_DATE(' 2021-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202112 values less than (TO_DATE(' 2022-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202201 values less than (TO_DATE(' 2022-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202202 values less than (TO_DATE(' 2022-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202203 values less than (TO_DATE(' 2022-04-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202204 values less than (TO_DATE(' 2022-05-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202205 values less than (TO_DATE(' 2022-06-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202206 values less than (TO_DATE(' 2022-07-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202207 values less than (TO_DATE(' 2022-08-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202208 values less than (TO_DATE(' 2022-09-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202209 values less than (TO_DATE(' 2022-10-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202210 values less than (TO_DATE(' 2022-11-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202211 values less than (TO_DATE(' 2022-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_P202212 values less than (TO_DATE(' 2023-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')) tablespace par,
- partition lucifer_MAX values less than (maxvalue) tablespace par)
- enable row movement
- tablespace par;
如上,唯一索引和約束不加,會(huì)自動(dòng)復(fù)制,分區(qū)表結(jié)構(gòu)的中間表已經(jīng)生成。
4、檢查中間表是否開啟行遷移
- select row_movement from dba_tables where table_name='LUCIFER' and owner='PAR';
- select row_movement from dba_tables where table_name='LUCIFER_PAR' and owner='PAR';
5、收集表統(tǒng)計(jì)信息
為了確保數(shù)據(jù)準(zhǔn)確,開始前進(jìn)行統(tǒng)計(jì)信息收集:
- sqlplus / as sysdba
- exec dbms_stats.gather_table_stats(ownname => 'PAR',tabname => 'LUCIFER',estimate_percent => 10,method_opt=> 'for all indexed columns',cascade=>TRUE,degree => '8') ;
- exec dbms_stats.gather_table_stats(ownname => 'PAR',tabname => 'LUCIFER_PAR',estimate_percent => 10,method_opt=> 'for all indexed columns',cascade=>TRUE,degree => '8') ;
6、開始在線重定義
- sqlplus / as sysdba
- EXEC DBMS_REDEFINITION.START_REDEF_TABLE('PAR','LUCIFER','LUCIFER_PAR');
7、復(fù)制表屬性,排除索引
選擇自動(dòng)復(fù)制表屬性,手動(dòng)創(chuàng)建本地索引(local):
- 優(yōu)點(diǎn):只需要關(guān)注索引是否遺漏,無(wú)需關(guān)注觸發(fā)器,權(quán)限,約束等依賴。
- 缺點(diǎn):需要手動(dòng)創(chuàng)建索引,并且結(jié)束后手動(dòng)rename索引。
- sqlplus par/par
- SET SERVEROUTPUT ON
- DECLARE
- l_errors NUMBER;
- BEGIN
- DBMS_REDEFINITION.copy_table_dependents(
- uname => USER,
- orig_table => 'LUCIFER',
- int_table => 'LUCIFER_PAR',
- copy_indexes => 0,
- copy_triggers => TRUE,
- copy_constraints => TRUE,
- copy_privileges => TRUE,
- ignore_errors => FALSE,
- num_errors => l_errors,
- copy_statistics => FALSE,
- copy_mvlog => FALSE);
- DBMS_OUTPUT.put_line('Errors=' || l_errors);
- END;
- /
執(zhí)行過(guò)程沒(méi)有任何報(bào)錯(cuò),代表正常。
8、中間表創(chuàng)建本地索引
中間表LUCIFER_PAR創(chuàng)建索引:
- create index ID_NAME_PAR on LUCIFER_PAR(NAME) tablespace PAR local parallel 8;
注意:索引名稱需要與原索引名稱不一致。
9、取消索引并行度
如果創(chuàng)建索引時(shí),開啟并行創(chuàng)建,則需要取消索引并行度:
- sqlplus / as sysdba
- select 'alter index '||owner||'.'||index_name||' noparallel;'
- from dba_indexes
- where table_name = 'LUCIFER_PAR' and owner= 'PAR';
10、同步數(shù)據(jù)(可以減少結(jié)束重定義過(guò)程的鎖表時(shí)間)
- sqlplus / as sysdba
- BEGIN
- dbms_redefinition.sync_interim_table(
- uname => 'PAR',
- orig_table => 'LUCIFER',
- int_table => 'LUCIFER_PAR');
- END;
- /
注意: 這一步操作是為了在結(jié)束重定義的時(shí)候,減少鎖表的時(shí)間。
11、收集中間表統(tǒng)計(jì)信息
為了下面同步數(shù)據(jù)做準(zhǔn)備,收集中間表統(tǒng)計(jì)信息:
- sqlplus / as sysdba
- exec dbms_stats.gather_table_stats(ownname => 'PAR',tabname => 'LUCIFER_PAR',estimate_percent => 10,method_opt=> 'for all indexed columns',cascade=>TRUE,degree => '8') ;
12、結(jié)束重定義(結(jié)束重定義需要鎖表,具體時(shí)間根據(jù)表的大小決定)
- sqlplus / as sysdba
- BEGIN
- dbms_redefinition.finish_redef_table(
- uname => 'PAR',
- orig_table => 'LUCIFER',
- int_table => 'LUCIFER_PAR');
- END;
- /
13、查看分區(qū)表是否已轉(zhuǎn)換
- sqlplus par/par
- select owner,table_name,partitioned from user_tables where table_name in ('LUCIFER','LUCIFER_PAR');
如上,LUCIFER表已經(jīng)在線重定義為分區(qū)表結(jié)構(gòu)。
14、手動(dòng)修改重命名索引
此時(shí),原表名的表已經(jīng)轉(zhuǎn)換為中間表,需要先將原表的索引,rename到其他名字,本次是BAK,需要注意索引名稱長(zhǎng)度不能過(guò)長(zhǎng)
- sqlplus / as sysdba
- ALTER index PAR.ID_NAME RENAME TO ID_NAME_BAK;
rename新分區(qū)表索引,由于新分區(qū)表的索引名稱還是中間表的索引名稱,所以需要手動(dòng)rename:
- sqlplus / as sysdba
- ALTER index PAR.ID_NAME_PAR RENAME TO ID_NAME;
15、查看是否存在無(wú)效索引
- sqlplus / as sysdba
- SELECT owner index_owner, index_name, index_type,'N/A' partition_name,status,table_name,tablespace_name,
- 'alter index '||owner||'.'||index_name||' rebuild;' rebuild_index
- FROM dba_indexes
- WHERE status = 'UNUSABLE'
- UNION ALL
- SELECT a.index_owner,a.index_name,b.index_type,a.partition_name,a.status,b.table_name,a.tablespace_name,
- 'alter index '||a.index_owner||'.'||a.index_name||' rebuild partition '||a.partition_name||' ;' rebuild_index
- FROM dba_ind_partitions a, dba_indexes b
- WHERE a.index_name = b.index_name
- AND a.index_owner = b.owner
- AND a.status = 'UNUSABLE'
- UNION ALL
- SELECT owner index_owner,a.index_name,b.index_type,'N/A' partition_name,a.status,b.table_name,NULL,
- 'alter index '||a.index_owner||'.'||a.index_name||' rebuild subpartition '||a.subpartition_name||';' rebuild_index
- FROM dba_ind_subpartitions a, dba_indexes b
- WHERE a.index_name = b.index_name
- AND a.index_owner = b.owner
- AND a.status = 'UNUSABLE';
16、檢查切換后是否開啟row_movement
- sqlplus / as sysdba
- select owner,table_name,row_movement from dba_tables where table_name in ('LUCIFER','LUCIFER_PAR') and owner='PAR';
17、檢查無(wú)效對(duì)象
- ##無(wú)效對(duì)象編譯
- sqlplus / as sysdba
- @?/rdbms/admin/utlrp.sql
- select 'alter '||object_type||' '||owner||'.'||object_name||' compile;'
- from dba_objects t
- where t.status = 'INVALID' order by 1;
18、收集統(tǒng)計(jì)信息
- sqlplus / as sysdba
- exec dbms_stats.gather_table_stats(ownname => 'PAR',tabname => 'LUCIFER',estimate_percent => 10,method_opt=> 'for all indexed columns',cascade=>TRUE,degree => '8') ;
19、插入測(cè)試數(shù)據(jù)
- sqlplus par/par
- begin
- for i in 100 .. 124 loop
- insert into lucifer values
- (i,
- 'lcuifer_' || i,
- add_months(to_date('2021-5-1', 'yyyy-mm-dd'), i));
- end loop;
- commit;
- end;
- /
20、查詢分區(qū)表數(shù)據(jù)分布
- sqlplus par/par
- SELECT COUNT(*) FROM LUCIFER;
- SELECT * FROM LUCIFER PARTITION(LUCIFER_P202101);
- SELECT * FROM LUCIFER PARTITION(LUCIFER_P202201);
- SELECT * FROM LUCIFER PARTITION(LUCIFER_MAX);
可以發(fā)現(xiàn),數(shù)據(jù)已經(jīng)根據(jù)日期均勻分布在不同的子分區(qū)中。
至此,在線重定義已經(jīng)完成,分區(qū)表已成功轉(zhuǎn)換。
「參考MOS文檔:」
- How To Partition Existing Table Using DBMS_REDEFINITION (Doc ID 472449.1)