统计信息的备份
一般重新收集table 或index 都會(huì)有風(fēng)險(xiǎn),需要把之前的統(tǒng)計(jì)信息備份下,萬(wàn)一收集后performance 沒(méi)有之前好,已經(jīng)將備份的統(tǒng)計(jì)信息導(dǎo)入快速恢復(fù)。
創(chuàng)建統(tǒng)計(jì)信息備份表
begin
dbms_stats.create_stat_table(ownname => 'SYSTEM',stattab => 'STAT_BK');
end;
/
?
生成表統(tǒng)計(jì)信息導(dǎo)出備份腳本
select 'begin dbms_stats.export_table_stats(ownname => ' || chr(39) ||
?????? b.owner || chr(39) || ',tabname =>' || chr(39) || b.table_name ||
??????chr(39) || ',stattab =>' || chr(39) || 'STAT_BK' || chr(39) ||
?????? ',statown =>' || chr(39) || 'SYSTEM' || chr(39) ||
?????? ',cascade => true); end; /'
?from dba_segments a, dba_tables b
?where a.tablespace_name IN ('DW_100M_DT')
?? and a.segment_type = 'TABLE'
?? and a.owner = b.owner
?? and a.segment_name = b.table_name;
?
begin
SYS.dbms_stats.export_table_stats(ownname => 'MESTST',tabname =>'ACTIONMAP',stattab =>'STAT_BK',cascade => true,statown=>'SYSTEM');
end;
/
?
生成索引統(tǒng)計(jì)信息導(dǎo)出備份腳本
select 'begin dbms_stats.export_index_stats(ownname => ' || chr(39) ||
?????? b.owner || chr(39) || ',indname =>' || chr(39) || b.index_name ||
?????? chr(39) || ',stattab =>' || chr(39) || 'STAT_BK' || chr(39) ||
?????? ',statown =>' || chr(39) || 'SYSTEM' || chr(39) || '); end; / '
?from dba_segments a, dba_indexes b
?where a.tablespace_name IN ('GW_100M_DATN', 'GW_100M_IDXN')
?? and a.segment_type = 'INDEX'
?? and a.owner = b.owner
?? and a.segment_name = b.index_name
union
select 'begin dbms_stats.export_index_stats(ownname => ' || chr(39) ||
?????? b.owner || chr(39) || ',indname =>' || chr(39) || b.index_name ||
?????? chr(39) || ',stattab =>' || chr(39) || 'STAT_BK' || chr(39) ||
?????? ',statown =>' || chr(39) || 'SYSTEM' || chr(39) || '); end; / '
?from dba_segments a, dba_indexes b
?where a.tablespace_name IN ('GW_100M_DATN', 'GW_100M_IDXN')
??and a.segment_type = 'TABLE'
?? and a.owner = b.table_owner
?? and a.segment_name = b.table_name;
?
IMPORT 表的統(tǒng)計(jì)信息
begin
SYS.dbms_stats.IMPORT_TABLE_STATS(ownname => 'MESTST',tabname =>'ACTIONMAP',stattab =>'STAT_BK',cascade => true,statown=>'SYSTEM');
end;
/
轉(zhuǎn)載于:https://www.cnblogs.com/yifan268/archive/2011/01/27/1946353.html
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