Re: optimization/indexing
Re: optimization/indexing
- Subject: Re: optimization/indexing
- From: Jeff Schmitz <email@hidden>
- Date: Thu, 18 Dec 2008 22:11:06 -0600
"LOBs"? Sorry, I'm not familiar with that term.
I have set the EOAdaptorDebugEnabled flag. Below is the output from a
ERXBatchFetchUtilities.batchFetch call that takes 94 seconds. It's
traversing something like a 1 to 65 to 2 relationship.
Dec 18 20:48:38 netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG
NSLog - === Begin Internal TransactionDec 18 20:48:38
netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG NSLog -
evaluateExpression: <com.webobjects.jdbcadaptor._FrontBasePlugIn
$FrontbaseExpression: "SELECT t0."entryID", t0."c_game", t0."c_group",
t0."id", t0."c_items", t0."c_score"
, t0."c_selected_item", t0."c_selected_weight" FROM "t_combo_team" t0
WHERE (t0."entryID" = 1000001 OR t0."entryID" = 1000002)"
withBindings: >
Dec 18 20:48:38 netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG
NSLog - 126 row(s) processed
Dec 18 20:48:38 netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG
NSLog - === Commit Internal Transaction
Dec 18 20:48:38 netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG
NSLog - === Begin Internal TransactionDec 18 20:48:38
netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG NSLog -
evaluateExpression: <com.webobjects.jdbcadaptor._FrontBasePlugIn
$FrontbaseExpression: "SELECT t0."comboTeamID", t0."c_count", t0."id",
t0."c_must", t0."c_must_team", t0."c_place" FROM "WinAnalysis" t0
WHERE (t0."comboTeamID" = 1000114 OR t0."comboTeamID" = 1000098 OR
t0."comboTeamID" = 1000067 OR t0."comboTeamID" = 1000071 OR
t0."comboTeamID" = 1000101 OR t0."comboTeamID" = 1000080 OR
t0."comboTeamID" = 1000085 OR t0."comboTeamID" = 1000078 OR
t0."comboTeamID" = 1000088 OR t0."comboTeamID" = 1000122 OR
t0."comboTeamID" = 1000076 OR t0."comboTeamID" = 1000116 OR
t0."comboTeamID" = 1000125 OR t0."comboTeamID" = 1000110 OR
t0."comboTeamID" = 1000069 OR t0."comboTeamID" = 1000092 OR
t0."comboTeamID" = 1000086 OR t0."comboTeamID" = 1000064 OR
t0."comboTeamID" = 1000074 OR t0."comboTeamID" = 1000119 OR
t0."comboTeamID" = 1000100 OR t0."comboTeamID" = 1000093 OR
t0."comboTeamID" = 1000066 OR t0."comboTeamID" = 1000099 OR
t0."comboTeamID" = 1000120 OR t0."comboTeamID" = 1000121 OR
t0."comboTeamID" = 1000105 OR t0."comboTeamID" = 1000097 OR
t0."comboTeamID" = 1000089 OR t0."comboTeamID" = 1000126 OR
t0."comboTeamID" = 1000117 OR t0."comboTeamID" = 1000095 OR
t0."comboTeamID" = 1000104 OR t0."comboTeamID" = 1000077 OR
t0."comboTeamID" = 1000109 OR t0."comboTeamID" = 1000090 OR
t0."comboTeamID" = 1000075 OR t0."comboTeamID" = 1000096 OR
t0."comboTeamID" = 1000079 OR t0."comboTeamID" = 1000081 OR
t0."comboTeamID" = 1000111 OR t0."comboTeamID" = 1000091 OR
t0."comboTeamID" = 1000087 OR t0."comboTeamID" = 1000106 OR
t0."comboTeamID" = 1000124 OR t0."comboTeamID" = 1000084 OR
t0."comboTeamID" = 1000108 OR t0."comboTeamID" = 1000068 OR
t0."comboTeamID" = 1000113 OR t0."comboTeamID" = 1000094 OR
t0."comboTeamID" = 1000107 OR t0."comboTeamID" = 1000070 OR
t0."comboTeamID" = 1000072 OR t0."comboTeamID" = 1000102 OR
t0."comboTeamID" = 1000112 OR t0."comboTeamID" = 1000103 OR
t0."comboTeamID" = 1000082 OR t0."comboTeamID" = 1000118 OR
t0."comboTeamID" = 1000065 OR t0."comboTeamID" = 1000073 OR
t0."comboTeamID" = 1000123 OR t0."comboTeamID" = 1000083 OR
t0."comboTeamID" = 1000115)" withBindings: >
Dec 18 20:50:12 netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG
NSLog - 189 row(s) processed
Dec 18 20:50:12 netBrackets[2001] (ERXNSLogLog4jBridge.java:46) DEBUG
NSLog - === Commit Internal Transaction
On Dec 18, 2008, at 9:52 PM, Clark Mueller wrote:
Jeff,
What does your model/database schema actually look like? Have you
tried setting EOAdaptorDebugEnabled to true in your launch config
(or via property)? How do the LOBs fit into your design?
Clark
On 18-Dec-08, at 7:41 PM, Jeff Schmitz wrote:
By consider a different design, do you mean something like the
below (from the wiki)? Coming form an OO world, I perhaps took the
paradigm too far and chopped up my data into too many tables? e.g.
Would denormalizing my 1 --> 65 --> 2 tables into a single table
help? Or would a better suggestion be to use "blobs" for the 65--
>2 part so in the end I'd have a relationship of 1-->1 blob? If
the blob route, can I assume you wouldn't want the optimistic
locking to check the blob for changes?
A common experience with large and complex object model, is that
people model their objects, then do a large fetch and find out that
bringing in a large set of EO's can be really slow .
Adapt your model
When you are going to be using a relational to object mapping
library (like EOF), you should expect that this will change your
requirements; enough that you can adapt your model to fit the tool.
If fetching an EO is heavy/slow, then generally the fewer objects
you bring in, the faster your system will perform. So if you
collapse and denormalize many small tables, into a few bigger ones,
you will be doing fewer EO loads, and probably dealing less with
all that fault and relationship management of all those little
fragments and relationships; which can result in performance savings.
You can do this a little by flattening relationships, or using
views in the database to make things appear to be flatter than they
are; or you can go right to model and actually flatten. Arguments
can be made for each, depending on your requirements.
You can even go further, and start moving complex data structures
and relationships into blobs that you manage yourself. This
offloads EOF from managing them, and often allows you to speed
things up; but the cost is more code maintenance on your part, and
of course denormalizing can negatively impact the design so you
want to be careful about how zealously you go down this path.
On Dec 17, 2008, at 12:39 PM, Chuck Hill wrote:
On Dec 17, 2008, at 9:25 AM, Jeff Schmitz wrote:
Yes, now that I think of it, there is one of these "crazy" joins
that's probably coming into play that joins each of my 7000 rows
with 65 rows in a different table, so that table must have about
450,000 rows. Any good optimization approaches for these type of
one to "very many" relationships? recursive fetch? I can see
this table getting into the many millions of rows real fast.
I'd spend some quality time considering a different design. I
doubt it is doing a crazy join. My money would be on Mike's
prediction of insane amounts of rapidly scrolling SQL.
ERXBatchFetching can be a big help here, properly used.
Chuck
On Tuesday, December 16, 2008, at 11:09PM, "Chuck Hill" <email@hidden
> wrote:
Either some crazy joins with other tables or something you are not
aware of is going on. 7K rows is tiny.
Chuck
On Dec 16, 2008, at 9:07 PM, Jeff Schmitz wrote:
hmm, I'm not doing an insert at all, just a read. Kind of
thought
there must be something else too though (with my limited
experience)
but figured indexing would be a good thing to do regardless
before
digging into debugging the real culprit here.
Jeff
On Dec 16, 2008, at 11:01 PM, Mike Schrag wrote:
More than a minute to insert to a 7000 row table?
Do other operations on the same DB take an appropriate amount
of
time? If not I would start looking at DNS or other
connectivity
issues. I can't fathom a FB DB sucking at that level.
this was my first thought, too ... something else is going on
here. I suspect if sql debug was turned on, you'd see tons of
faulting going on that you didn't realize and that the insert
itself is not actually the slow thing.
ms
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--
Chuck Hill Senior Consultant / VP Development
Practical WebObjects - for developers who want to increase their
overall knowledge of WebObjects or who are trying to solve
specific
problems.
http://www.global-village.net/products/practical_webobjects
--
Chuck Hill Senior Consultant / VP Development
Practical WebObjects - for developers who want to increase their
overall knowledge of WebObjects or who are trying to solve
specific problems.
http://www.global-village.net/products/practical_webobjects
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