RE: FILL FACTOR
> Neil Truby wrote:
>> Having spent about half an hour looking for a CREATE INDEX example
>> showing show to use the FILLFACTOR option I now can't find how to
>>display the current fill factor for an index!
Maybe you have to "reverse engineer" it with oncheck -pT on the table.
Thought process:
fillfactor tells how much space to reserve in index LEAF pages....or
rather 100-fillfactor=% space to reserve for growth.
oncheck -pT shows you "Index Usage Report" indicating how many levelsare in your index and the "avg free bytes" at each level.....so if you
have multiple levels in your index, the final leaf level should give you
some clue?
There must be a more simple way...
Maybe system catalog/sysmaster query
Maybe the OAT tool does it nicely in GUI form?
Anyway... Carrying on cuz I feel like rambling...
Here's an example of oncheck -pT with potentially bad math (I always
screw this stuff up):
-----------------------
TBLspace Usage Report for trg:sapr3.zzsub
Type Pages Empty Semi-Full Full
Very-Full
---------------- ---------- ---------- ---------- ----------
----------
Free 16
Bit-Map 1
Index 22
Data (Home) 26
----------
Total Pages 65
[ some sectons snipped out ]
Index Usage Report for index 36537_322383 on trg:sapr3.zzsub
Average Average
Level Total No. Keys Free Bytes
----- -------- -------- ----------
1 1 21 1612
2 21 67 610
----- -------- -------- ----------
Total 22 65 655
-------------------------
My LEAF level is #2, and it has an average of 610 free bytes/page.
I am on a 2K page, so 610/2048 = 29% free
Or if I have to subtract overhead.... 610/2020 = 30% free
I don't override FILLFACTOR in onconfig, my onconfig setting is 80.
So my above calc should show roughly 20% free.......
Maybe it didn't work cuz I am looking at a small table.
I could post the whole oncheck example for this, but someone will likely
post a much shorter solution :)
Norma Jean
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"Sebastian, Norma J." <NormaJean.Sebastian@tellabs.com> wrote in message
news:mailman.211.1199553710.20610.informix-list@iiug.org...
<94,000 lines removed>
I could post the whole oncheck example for this, but someone will likely
post a much shorter solution :)
I hope so! ;-)
Thanks for your interest.
A quick google search showed that this question was asked by someone else ...
Art's answer was that it wasn't possible since the FILLFACTOR wasn't stored. It was just used at creation time.
I'm not a physical DBA (too many databases) but maybe one of the sysmaster tables that describe the b-tree index would have the fill factor value?
> From: neil.truby@ardenta.com> Subject: Re: FILL FACTOR> Date: Sat, 5 Jan 2008 18:31:09 +0000> To: informix-list@iiug.org> > "Sebastian, Norma J." <NormaJean.Sebastian@tellabs.com> wrote in message > news:mailman.211.1199553710.20610.informix-list@iiug.org...> > <94,000 lines removed>> > I could post the whole oncheck example for this, but someone will likely> post a much shorter solution :)> > I hope so! ;-)> > Thanks for your interest. > > > _______________________________________________> Informix-list mailing list> Informix-list@iiug.org> http://www.iiug.org/mailman/listinfo/informix-list
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