41 lines
1.4 KiB
MySQL
41 lines
1.4 KiB
MySQL
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-- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com
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-- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions.
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drop table t;
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create table t PCTFREE 0 as select * from dba_source, (select 1 from dual connect by level<=5);
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--create table t PCTFREE 0 as select * from dba_source;
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-- deliberately using analyze table command to compute the number of chained rows
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analyze table t compute statistics;
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select num_rows,blocks,empty_blocks,chain_cnt from user_tables where table_name = 'T';
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update t set owner = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' where rownum <= 100000;
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commit;
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update t set owner = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' where rownum <= 100000;
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commit;
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update t set owner = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' where rownum <= 100000;
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commit;
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update t set owner = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' where rownum <= 100000;
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commit;
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update t set owner = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' where rownum <= 100000;
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commit;
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update t set owner = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' where rownum <= 100000;
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commit;
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analyze table t compute statistics;
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select num_rows,blocks,empty_blocks,chain_cnt from user_tables where table_name = 'T';
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--exec dbms_stats.gather_table_stats(user,'T');
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pause About to create the index, run snapper in another window on this session. Press ENTER to continue...
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create index i on t(case when owner = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA' then owner else null end) online;
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