乱色视频中文字幕,成人在线不卡视频

SQL>COL segment_name for a20
SQL>COL PARTITION_NAME for a20
SQL>SELECT segment_name, partition_name, tablespace_name
　　2FROM dba_segments
　　3WHERE segment_name='DBOBJS_IDX';
　　SEGMENT_NAME     PARTITION_NAME   TABLESPACE_NAME
　　----------------------------------------------------------------------
　　DBOBJS_IDX         DBOBJS_06         USERS
　　DBOBJS_IDX         DBOBJS_07         USERS
SQL>insert   into   dbobjs
　　2select object_id, object_name, created
　　3from   dba_objects   where   created
　　6227 rows created.

SQL>commit;
    Commitcomplete.

SQL>select count(*) from dbobjs partition(DBOBJS_06);
　　COUNT(*)
　　----------
　　6154

SQL>select count(*) from dbobjs partition(dbobjs_07);
　　COUNT(*)
　　----------
　　73

*************************************

我們可以通過查詢來對(duì)比一下分區(qū)表和非分區(qū)表的查詢性能差異:

SQL>set autotrace on
SQL>select count(*) from dbobjs where created<to_date('01/01/2008','dd/mm/yyyy');
　　COUNT(*)
　　----------
　　6227
　　ExecutionPlan
　　----------------------------------------------------------
　　0SELECTSTATEMENTptimizer=CHOOSE(Cost=1Card=1Bytes=9)
　　10SORT(AGGREGATE)
　　21PARTITIONRANGE(ALL)
　　32INDEX(RANGESCAN)OF'DBOBJS_IDX'(NON-UNIQUE)(Cost=2Card=8Bytes=72)
　　Statistics
　　----------------------------------------------------------
　　0recursivecalls
　　0dbblockgets
　　25consistentgets
　　0physicalreads
　　0redosize
　　380bytessentviaSQL*Nettoclient
　　503bytesreceivedviaSQL*Netfromclient
　　2SQL*Netroundtripsto/fromclient
　　0sorts(memory)
　　0sorts(disk)
　　1rowsprocessed

SQL>select count(*) from dbobjs where created<to_date('01/01/2007','dd/mm/yyyy');
　　COUNT(*)
　　----------
　　6154
　　ExecutionPlan
　　----------------------------------------------------------
　　0SELECTSTATEMENTptimizer=CHOOSE(Cost=1Card=1Bytes=9)
　　10SORT(AGGREGATE)
　　21INDEX(RANGESCAN)OF'DBOBJS_IDX'(NON-UNIQUE)(Cost=2Card=4Bytes=36)
　　Statistics
　　----------------------------------------------------------
　　0recursivecalls
　　0dbblockgets
　　24consistentgets
　　0physicalreads
　　0redosize
　　380bytessentviaSQL*Nettoclient
　　503bytesreceivedviaSQL*Netfromclient
　　2SQL*Netroundtripsto/fromclient
　　0sorts(memory)
　　0sorts(disk)
　　1rowsprocessed
SQL>selectc ount(distinct(object_name)) from dbobjs where created<to_date('01/01/2007','dd/mm/yyyy');
　　COUNT(DISTINCT(OBJECT_NAME))
　　----------------------------
　　4753
　　ExecutionPlan
　　----------------------------------------------------------
　　0SELECTSTATEMENTptimizer=CHOOSE(Cost=1Card=1Bytes=75)
　　10SORT(GROUPBY)
　　21TABLEACCESS(BYLOCALINDEXROWID)OF'DBOBJS'(Cost=1Card=4Bytes=300)
　　32INDEX(RANGESCAN)OF'DBOBJS_IDX'(NON-UNIQUE)(Cost=2Card=1)
　　Statistics
　　----------------------------------------------------------
　　0recursivecalls
　　0dbblockgets
　　101consistentgets
　　0physicalreads
　　0redosize
　　400bytessentviaSQL*Nettoclient
　　503bytesreceivedviaSQL*Netfromclient
　　2SQL*Netroundtripsto/fromclient
　　1sorts(memory)
　　0sorts(disk)
　　1rowsprocessed

********************************************************
對(duì)于非分區(qū)表的測(cè)試:

SQL>CREATE TABLE dbobjs2
　　2(object_id NUMBER NOT NULL,
　　3object_name VARCHAR2(128),
　　4created DATE NOT NULL
　　5);
　　Tablecreated.
SQL>CREATE INDEX dbobjs_idx2 ON dbobjs2(created);
　　Index created.
SQL>insert into dbobjs2
　　2select object_id, object_name, created
　　3from dba_objects where created
　　6227rowscreated.
SQL>commit;
　　Commitcomplete.
SQL>select count(distinct(object_name))
from dbobjs2
where created<to_date'01/01/2007','dd/mm/yyyy');

　　COUNT(DISTINCT(OBJECT_NAME))
　　----------------------------
　　4753
　　ExecutionPlan
　　----------------------------------------------------------
　　0SELECTSTATEMENTptimizer=CHOOSE
　　10SORT(GROUPBY)
　　21TABLEACCESS(BYINDEXROWID)OF'DBOBJS2'
　　32INDEX(RANGESCAN)OF'DBOBJS_IDX2'(NON-UNIQUE)
　　Statistics
　　----------------------------------------------------------
　　0recursivecalls
　　0dbblockgets
　　2670consistentgets
　　0physicalreads
　　1332redosize
　　400bytessentviaSQL*Nettoclient
　　503bytesreceivedviaSQL*Netfromclient
　　2SQL*Netroundtripsto/fromclient
　　1sorts(memory)
　　0sorts(disk)
　　1rowsprocessed
******************************

當(dāng)增加表分區(qū)時(shí)，LOCAL索引被自動(dòng)維護(hù):

SQL>ALTER TABLE dbobjs ADD PARTITION dbobjs_08 VALUES LESS THAN(TO_DATE('01/01/2009','DD/MM/YYYY'));
　　Table altered.
SQL>set autotrace off
SQL>COL segment_name for a20
SQL>COL PARTITION_NAME for a20
SQL>SELECT segment_name, partition_name, tablespace_name FROM dba_segments WHERE segment_name='DBOBJS_IDX';
　　SEGMENT_NAME      PARTITION_NAME      TABLESPACE_NAME
　　----------------------------------------------------------------------
　　DBOBJS_IDX         DBOBJS_06            USERS
　　DBOBJS_IDX         DBOBJS_07            USERS
　　DBOBJS_IDX         DBOBJS_08            EYGLE

SQL>SELECT segment_name, partition_name, tablespace_name FROM dba_segments WHERE segment_name='DBOBJS';
　　SEGMENT_NAME      PARTITION_NAME      TABLESPACE_NAME
　　----------------------------------------------------------------------
　　DBOBJS            DBOBJS_06            EYGLE
　　DBOBJS            DBOBJS_07            EYGLE
　　DBOBJS            DBOBJS_08            EYGLE

*************************************************************************************

--The End---

本站僅提供存儲(chǔ)服務(wù)，所有內(nèi)容均由用戶發(fā)布，如發(fā)現(xiàn)有害或侵權(quán)內(nèi)容，請(qǐng)點(diǎn)擊舉報(bào)。

免费视频淫片aa毛片_日韩高清在线亚洲专区vr_日韩大片免费观看视频播放_亚洲欧美国产精品完整版