从Oracle8开始，提供了从分区交换的功能，如一个分区或子分区与一个非分区表交换、一个hash分区与另一个表的hash子分区交换等等，详细的交换方式可以参考官方文档。
基本语法：ALTER TABLE...EXCHANGE PARTITION
实验环境：11.2.0.4
zx@ORCL>select*fromv$version; BANNER ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ OracleDatabase11gEnterpriseEditionRelease11.2.0.4.0-64bitProduction PL/sqlRelease11.2.0.4.0-Production CORE11.2.0.4.0Production TNSforLinux:Version11.2.0.4.0-Production NLSRTLVersion11.2.0.4.0-Production
一、测试分区交换
创建测试表
--分区表 zx@ORCL>createtablet1 2(idnumber(2),3namevarchar2(15)) 4tablespacett 5partitionbyrange(id) 6(partitionp1valueslessthan(10),7partitionp2valueslessthan(20),8partitionp3valueslessthan(30)); Tablecreated. --非分区表 zx@ORCL>createtablet2(idnumber(2),namevarchar2(15))tablespaceusers; Tablecreated. --插入测试数据 zx@ORCL>insertintot1values(1,'1'); 1rowcreated. zx@ORCL>insertintot1values(11,'11'); 1rowcreated. zx@ORCL>insertintot1values(21,'21'); 1rowcreated. zx@ORCL>insertintot2values(2,'2'); 1rowcreated. zx@ORCL>commit; Commitcomplete. zx@ORCL>select*fromt1; IDNAME ------------------------------------------------------- 11 1111 2121 zx@ORCL>select*fromt2; IDNAME ------------------------------------------------------- 22 --查看表存储表空间 --t2在USERS表空间，t1各个分区都在TT表空间 zx@ORCL>colsegment_namefora20 zx@ORCL>colpartition_namefora15 zx@ORCL>coltablespace_namefora15 zx@ORCL>selectsegment_name,partition_name,tablespace_namefromdba_segmentswheresegment_namein('T1','T2'); SEGMENT_NAMEPARTITION_NAMetaBLESPACE_NAME -------------------------------------------------- T2USERS T1P3TT T1P2TT T1P1TT --查看各表的extent信息 zx@ORCL>selectSEGMENT_NAME,BLOCK_ID,BLOCKS,TABLESPACE_NAMEfromdba_extentswheresegment_name='T2'; SEGMENT_NAMEBLOCK_IDBLOCKSTABLESPACE_NAME ------------------------------------------------------- T21928USERS zx@ORCL>selectSEGMENT_NAME,PARTITION_NAME,TABLESPACE_NAMEfromdba_extentswheresegment_name='T1'; SEGMENT_NAMEPARTITION_NAMEBLOCK_IDBLOCKSTABLESPACE_NAME ---------------------------------------------------------------------- T1P2213761024TT T1P3224001024TT T1P1203521024TT
t1分区p1与t2表交换分区
--分区 zx@ORCL>altertablet1exchangepartitionp1withtablet2; Tablealtered. zx@ORCL>select*fromt2; IDNAME ------------------------------------------------------- 11 zx@ORCL>select*fromt1; IDNAME ------------------------------------------------------- 22 1111 2121
可以看到p1分区里的数据交换到了t2表里，而t2表里里的数据也存储到了t1表中。再次查看各表所在的表空间和extent
--查看表空间 zx@ORCL>selectsegment_name,'T2'); SEGMENT_NAMEPARTITION_NAMetaBLESPACE_NAME -------------------------------------------------- T2TT T1P3TT T1P2TT T1P1USERS --查看extent zx@ORCL>selectSEGMENT_NAME,TABLESPACE_NAMEfromdba_extentswheresegment_name='T2'; SEGMENT_NAMEBLOCK_IDBLOCKSTABLESPACE_NAME ------------------------------------------------------- T2203521024TT zx@ORCL>selectSEGMENT_NAME,TABLESPACE_NAMEfromdba_extentswheresegment_name='T1'; SEGMENT_NAMEPARTITION_NAMEBLOCK_IDBLOCKSTABLESPACE_NAME ---------------------------------------------------------------------- T1P11928USERS T1P2213761024TT T1P3224001024TT
从结果看到T2已经到了TT表空间，而T1的P1分区移动到了USERS表空间，而且P1分区与T2表的extent也做了交换，可以推断实际表里的数据没有移动位置，只是把数据字典里的相关信息做了更换。
二、再看看交换分区对于分区表的索引的影响
在分区表中创建索引
--全局索引 zx@ORCL>createindexidx_t1_idont1(id); Indexcreated. --分区索引 zx@ORCL>createindexidx_t1_nameont1(name)local; Indexcreated. zx@ORCL>selectindex_name,statusfromuser_indexeswhereindex_namelike'IDX_T1%'; INDEX_NAMESTATUS ------------------------------------------------------------------------------------------------------------------ IDX_T1_IDVALID IDX_T1_NAMEN/A zx@ORCL>selectindex_name,statusfromuser_ind_partitionswhereindex_namelike'IDX_T1%'; INDEX_NAMEPARTITION_NAMESTATUS --------------------------------------------------------------------------------------------------------------------------------- IDX_T1_NAMEP1USABLE IDX_T1_NAMEP2USABLE IDX_T1_NAMEP3USABLE
交换分区查看是否对索引有影响
zx@ORCL>altertablet1exchangepartitionp1withtablet2; Tablealtered. zx@ORCL>selectindex_name,statusfromuser_indexeswhereindex_namelike'IDX_T1%'; INDEX_NAMESTATUS ------------------------------------------------------------------------------------------------------------------ IDX_T1_NAMEN/A IDX_T1_IDUNUSABLE zx@ORCL>selectindex_name,statusfromuser_ind_partitionswhereindex_namelike'IDX_T1%'; INDEX_NAMEPARTITION_NAMESTATUS --------------------------------------------------------------------------------------------------------------------------------- IDX_T1_NAMEP1UNUSABLE IDX_T1_NAMEP2USABLE IDX_T1_NAMEP3USABLE
看到全局索引IDX_T1_ID失效了，分区P1对应的分区索引也失效了，但其他分区的分区没有受到影响
交换分区时加入 UPDATE INDEXES子句
zx@ORCL>alterindexidx_t1_idrebuild; Indexaltered. zx@ORCL>alterindexidx_t1_namerebuildpartitionp1; Indexaltered. zx@ORCL>selectindex_name,statusfromuser_indexeswhereindex_namelike'IDX_T1%'; INDEX_NAMESTATUS ------------------------------------------------------------------------------------------------------------------ IDX_T1_NAMEN/A IDX_T1_IDVALID zx@ORCL>selectindex_name,statusfromuser_ind_partitionswhereindex_namelike'IDX_T1%'; INDEX_NAMEPARTITION_NAMESTATUS --------------------------------------------------------------------------------------------------------------------------------- IDX_T1_NAMEP1USABLE IDX_T1_NAMEP2USABLE IDX_T1_NAMEP3USABLE zx@ORCL>altertablet1exchangepartitionp1withtablet2updateindexes; Tablealtered. zx@ORCL>selectindex_name,statusfromuser_ind_partitionswhereindex_namelike'IDX_T1%'; INDEX_NAMEPARTITION_NAMESTATUS --------------------------------------------------------------------------------------------------------------------------------- IDX_T1_NAMEP1UNUSABLE IDX_T1_NAMEP2USABLE IDX_T1_NAMEP3USABLE
可以看到全局索引没有受影响，但是分区索引仍然失效。
更多信息参考官方文档：http://docs.oracle.com/cd/E11882_01/server.112/e25523/part_admin002.htm#i1107555
原文地址：https://www.jb51.cc/oracle/210797.html
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