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Message	Score	Author	Date
Hi Friends, I reduced the datafile size and try......		sathish kumar	Jun 27, 2012, 20:01
SQL> select file_name, 2 ceil( (nvl(hwm,1)*&&b......		sathish kumar	Jun 27, 2012, 20:02
Hi, Just curious, are you doing this exercise s......		BenBart BartBen	Jun 28, 2012, 04:12

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Subject:	High Water mark
Author:	sathish kumar, India
Date:	Jun 27, 2012, 20:01, 2967 days ago
Os info:	Any OS
Oracle info:	oracle Any Version
Message:	Hi Friends, I reduced the datafile size and try to release the free blocks. I tried like below. select a.tablespace_name, a.file_name, ceil( (nvl(hwm,1)*8192)/1024/1024 ) from dba_data_files a, ( select file_id, max(block_id+blocks-1) hwm from dba_extents group by file_id) b where a.file_id = b.file_id(+) AND A.TABLESPACE_NAME='TBS' order by tablespace_name, file_name; TABLESPACE_NAME FILE_NAME Mo ------------------------------ --------------------- -------- TBS /oradata1/oradata/testdb/TBS02.dbf 24576 TBS /oradata3/oradata/testdb/TBS01.dbf 25600 TBS /oradata2/oradata/testdb/TBS04.dbf 14652 SQL> SELECT BYTES/1024/1024,FILE_NAME FROM DBA_DATA_FILES WHERE TABLESPACE_NAME='TBS'; BYTES/1024/1024 FILE_NAME --------------- -------------- 25600 /oradata3/oradata/testdb/TBS01.dbf 21600 /oradata2/oradata/testdb/TBS04.dbf 24576 /oradata1/oradata/testdb/TBS02.dbf SQL> select file_name, 2 ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) smallest, 3 ceil( blocks*&&blksize/1024/1024) currsize, 4 ceil( blocks*&&blksize/1024/1024) - 5 ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) savings from dba_data_files a, 6 7 ( select file_id, max(block_id+blocks-1) hwm 8 from dba_extents 9 group by file_id ) b 10 where a.file_id = b.file_id(+) and a.TABLESPACE_NAME='TBS'; 11 Enter value for blksize: 8192 old 2: ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) smallest, new 2: ceil( (nvl(hwm,1)*8192)/1024/1024 ) smallest, old 3: ceil( blocks*&&blksize/1024/1024) currsize, new 3: ceil( blocks*8192/1024/1024) currsize, old 4: ceil( blocks*&&blksize/1024/1024) - new 4: ceil( blocks*8192/1024/1024) - old 5: ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) savings new 5: ceil( (nvl(hwm,1)*8192)/1024/1024 ) savings FILE_NAME SMALLEST CURRSIZE SAVINGS --------------------------------------------- ---------- ---------- ---------- /oradata2/oradata/testdb/TBS04.dbf 14652 21600 6948 /oradata3/oradata/testdb/TBS01.dbf 25600 25600 0 /oradata1/oradata/testdb/TBS02.dbf 24576 24576 0 SQL> SELECT NUM_ROWS,BLOCKS,EMPTY_BLOCKS AS EMPTY,AVG_SPACE,AVG_ROW_LEN FROM ALL_tables where owner='HR' and table_name='TEST1'; NUM_ROWS BLOCKS EMPTY AVG_SPACE AVG_ROW_LEN ---------- ---------- ---------- ---------- ----------- 77866 2318 1266 995 209 SQL> SQL> ALTER TABLE HR.TEST1 DEALLOCATE UNUSED KEEP 1000K; Table altered. SQL> SELECT NUM_ROWS,BLOCKS,EMPTY_BLOCKS AS EMPTY,AVG_SPACE,AVG_ROW_LEN FROM ALL_tables where owner='HR' and table_name='TEST1'; NUM_ROWS BLOCKS EMPTY AVG_SPACE AVG_ROW_LEN ---------- ---------- ---------- ---------- ----------- 77866 2318 1266 995 209 SQL> analyze table HR.TEST1 compute statistics; Table analyzed. SQL> SELECT NUM_ROWS,BLOCKS,EMPTY_BLOCKS AS EMPTY,AVG_SPACE,AVG_ROW_LEN FROM ALL_tables where owner='HR' and table_name='TEST1'; NUM_ROWS BLOCKS EMPTY AVG_SPACE AVG_ROW_LEN ---------- ---------- ---------- ---------- ----------- 77900 2318 178 990 209
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Subject:	Re: High Water mark
Author:	sathish kumar, India
Date:	Jun 27, 2012, 20:02, 2967 days ago
Message:	SQL> select file_name, 2 ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) smallest, 3 ceil( blocks*&&blksize/1024/1024) currsize, 4 ceil( blocks*&&blksize/1024/1024) - 5 ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) savings from dba_data_files a, 6 7 ( select file_id, max(block_id+blocks-1) hwm 8 from dba_extents 9 group by file_id ) b 10 where a.file_id = b.file_id(+) and a.TABLESPACE_NAME='TBS'; 11 old 2: ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) smallest, new 2: ceil( (nvl(hwm,1)*8192)/1024/1024 ) smallest, old 3: ceil( blocks*&&blksize/1024/1024) currsize, new 3: ceil( blocks*8192/1024/1024) currsize, old 4: ceil( blocks*&&blksize/1024/1024) - new 4: ceil( blocks*8192/1024/1024) - old 5: ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) savings new 5: ceil( (nvl(hwm,1)*8192)/1024/1024 ) savings FILE_NAME SMALLEST CURRSIZE SAVINGS --------------------------------------------- ---------- ---------- ---------- /oradata2/oradata/testdb/TBS04.dbf 14652 21600 6948 /oradata3/oradata/testdb/TBS01.dbf 25600 25600 0 /oradata1/oradata/testdb/TBS02.dbf 24576 24576 0 select a.tablespace_name, a.file_name, ceil( (nvl(hwm,1)*8192)/1024/1024 ) from dba_data_files a, ( select file_id, max(block_id+blocks-1) hwm from dba_extents group by file_id) b where a.file_id = b.file_id(+) AND A.TABLESPACE_NAME='TBS' order by tablespace_name, file_name; TABLESPACE_NAME FILE_NAME Mo ------------------------------ --------------------- -------- TBS /oradata1/oradata/testdb/TBS02.dbf 24576 TBS /oradata3/oradata/testdb/TBS01.dbf 25600 TBS /oradata2/oradata/testdb/TBS04.dbf 14652 1)My doubt is even if reduce 1000k, Why none of the datafile freespace is increased? 2)Also please let me know the steps i followed above is correct or not? 3)Please give the query to find the High Water Mark of 1)Specific Table 2)Specific Datafile 3)Entire Database Please help me. Thanks in Advance.
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Subject:	Re: High Water mark
Author:	BenBart BartBen, Philippines
Date:	Jun 28, 2012, 04:12, 2966 days ago
Message:	Hi, Just curious, are you doing this exercise so you will have more freespace on the tablespace in question? I don't see the point of playing around with resizing datafiles if eventually they will increase again due to usage.
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