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visits member for 2 years
seen Aug 14 '13 at 2:46

May
23
comment Find fragmented space free below HWM Oracle
Yes! definitely interested. I was reading quite a bit on it. Since I am studying the subject, can use quality material.
Apr
25
comment Efficient way to perform approximated search?
I am working on a few test records at the moment so couldn't really tell, but as soon as I have a more real bulk of data, I'll make sure update this info.
Jan
30
comment Count events on “user based” sliding window
thanks for the nice trick on how to create a window with only one value anyway :)
Jan
30
comment Count events on “user based” sliding window
Thanks for the answer, but is kind of that though. Maybe I didn't exactly get your question on the comments before, but, from what you did seems like we have the same "global" maximun as before. At that point my query would work too. I was wondering on how to use only the relevant maximun for each user (although, as I said, I believe the results wont change in this case). To that end, I figure your data query would have to look something like select TO_NUMBER(TO_CHAR(max(dt), 'J')) as maxwindow, usr from sales group by usr, isn't it?
Jan
29
comment Count events on “user based” sliding window
for the first window for example, max(dt) is the upper limit and max(dt) - [WindowSize] + 1 is the lower limit. for the second window, max(dt) - [WindowSize] for the upper, max(dt) - [2 x WindowSize] + 1 lower and so forth.
Oct
3
comment Why does the query cost change so much and how to prevent it
@ChrisSaxon Small has about 100 rows, medium nears 1k, huge is ~400 millions.
Oct
3
comment Why does the query cost change so much and how to prevent it
@VincentMalgrat I am not a dba, but I gave it a show based on what I read here dba-oracle.com/art_dbazine_oracle10g_dynamic_sampling_hint.htm it didn't work, but I might have applied it wrong (sorry, I can't really take the time to experiment all that much now). The hint I used was /*+ dynamic_sampling(my_id 10) */. thanks
Oct
3
comment Why does the query cost change so much and how to prevent it
@ChrisSaxon Sure, There you have it. I renamed the tables to make sense with the topic, hope I haven't messed it up.
Oct
2
comment Why does the query cost change so much and how to prevent it
@Phil The stats are fine, but thanks. And, there isn't any reason to not join.. I actually did try that, thats what I meant with "I have tried to isolate the "small query" in a with clause, tried to use an join instead a sub query", sorry if it was ambiguous.
Sep
27
comment Use of hash functions in group by?
You read it correctly, but it isn't the whole story. I've made it short so I could explain the question, but this comparison is just part of a whole process which isn't even executed by Oracle. What you said is probably a better idea in most cases but here I'd just want to generate the hashes to feed my other process (responsible for the comparison).
Sep
10
comment Help to understand explain plan in Oracle
Well, I was hoping for something like "the heaviest part of your query is the search on costumer_price_history by such field as shown in such line of the explain plan"
Sep
10
comment Help to understand explain plan in Oracle
Done. thanks for the heads up.