segment growth
From: Remigiusz Sokolowski <remigiusz.sokolowski_at_nordea.com>
Date: Wed, 2 Apr 2014 08:17:34 +0200
Message-ID: <533BAB7E.7030809_at_nordea.com>
I have just tried to realize how to count a segment growth trend based on the dba_hits_seg_stat rows.
And now I am puzzled:
1. on the metalink I have found the article 1395195.1, which suggests to simply sum the db_block_changes_delta
2. I displayed the data for some particular segment to find out the possible relations between numbers and I would say this is rather the value, which indicates literally the delta of block changes i.e. all the deletes, inserts, updates and not only new blocks - for example because the db_block_changes_delta is always positive and db_block_changes_total always grows
3. So I look at space_used_total assuming this is the total space used by the segment in the moment a snap is taken - and here longer example
current size of the object
-----------------
object_name | blocks | bytes
ZABBIX.ITEMS 4992 40894464
excerpt from snap values - few subsequent snaps
-----------------
OBJ_SNAP, SPACE_USED_TOTAL, SPACE_USED_DELTA,
13356 933731 9503
13357 937827 4096
13358 940940 3113
13359 -3277 -3277
13360 737 4014
13361 6062 5325
13362 7045 983
until 13358 all is fine I see the logic ( space_used_total(n)=space_used_total(n-1)+space_used_delta(n) )
but then negative total value (and the logic's gone) - no idea what to think about that.
And the main question - how to calculate the segment growth trend in a reliable manner?
Best regards
Remigiusz
-- http://www.freelists.org/webpage/oracle-l Received on Wed Apr 02 2014 - 08:17:34 CEST
Date: Wed, 2 Apr 2014 08:17:34 +0200
Message-ID: <533BAB7E.7030809_at_nordea.com>
hi,
I have just tried to realize how to count a segment growth trend based on the dba_hits_seg_stat rows.
And now I am puzzled:
1. on the metalink I have found the article 1395195.1, which suggests to simply sum the db_block_changes_delta
2. I displayed the data for some particular segment to find out the possible relations between numbers and I would say this is rather the value, which indicates literally the delta of block changes i.e. all the deletes, inserts, updates and not only new blocks - for example because the db_block_changes_delta is always positive and db_block_changes_total always grows
3. So I look at space_used_total assuming this is the total space used by the segment in the moment a snap is taken - and here longer example
current size of the object
-----------------
object_name | blocks | bytes
ZABBIX.ITEMS 4992 40894464
excerpt from snap values - few subsequent snaps
-----------------
OBJ_SNAP, SPACE_USED_TOTAL, SPACE_USED_DELTA,
13356 933731 9503
13357 937827 4096
13358 940940 3113
13359 -3277 -3277
13360 737 4014
13361 6062 5325
13362 7045 983
until 13358 all is fine I see the logic ( space_used_total(n)=space_used_total(n-1)+space_used_delta(n) )
but then negative total value (and the logic's gone) - no idea what to think about that.
And the main question - how to calculate the segment growth trend in a reliable manner?
Best regards
Remigiusz
-- Pole na kazi ---------------------------------------------------------------------- Remigiusz Sokolowski <remigiusz.sokolowski_at_nordea.com> pos : Senior DBA at DIiUSI comp : Nordea IT Polska Sp. z o.o. addr : Luzycka 6A st, 81-537 Gdynia, Poland phone : +48 58 667 17 43 mobile: +48 602 42 42 77 geo : 54.4952N 18.4332E
Nordea IT Polska Sp.z o.o. z siedzibą w 81-537 Gdynia, ul. Łużycka 6A wpisaną do Rejestru Przedsiębiorców Krajowego Rejestru Sądowego pod numerem: 0000429783, dla której dokumentację przechowuje Sąd Rejonowy dla M.St. Warszawy w Warszawie, XII Wydział Gospodarczy Krajowego Rejestru Sądowego, o kapitale zakładowym i opłaconym w wysokości: 40.000.000,00 złotych, NIP: 527-268-29-50, REGON: 146278110
-- http://www.freelists.org/webpage/oracle-l Received on Wed Apr 02 2014 - 08:17:34 CEST