RE: CMP 2.0 vs BMP - Which performes better?
Hi Jeff and other dear friends, I had this doubt in my mind very earlier. When we load very large amount of data from the database, how it can be handled? If we use result sets and iterate, this is going to take a long time? How can we limit the number of records that is present in the memory at a time? thanks, Prasanth. From: Jeff Schnitzer [EMAIL PROTECTED] Reply-To: Orion-Interest [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Subject: RE: CMP 2.0 vs BMP - Which performes better? Date: Thu, 4 Apr 2002 16:22:17 -0800 From: Curt Smith [mailto:[EMAIL PROTECTED]] There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. I'd like to know more of the details? How does the container deal with the following finder in CMP differently than BMP? Collection remoteRefs = home.findSalaryGreaterThan ( 50,000); Lets assume this produces 1000 results which you then iterate through. With BMP beans, this will require 1001 database queries. First the finder, then 1000 selects to load each bean. With CMP, it's actually rather ambiguous what will happen. Last time I checked, Orion will load all the beans into an ArrayList. Yes, lots of memory consumed, but a *lot* better than 1001 database hits. Admittedly a bigger problem with orders of magnitude more objects, but even with BMP you're going to choke if the finder query returns a billion rows of primary key data. Some containers (not Orion, I don't think) allow you to specify that finders should lazy-load beans. But this brings you back to BMP performance. Some containers allow you to define field groups to minimize the amount of data brought back (especially useful if you store blobs), but not Orion. Personally, I don't understand why containers don't implement Collections backed by the ResultSet directly. 98% of the time, the client just creates an iterator and walks the results. If the client does something that the ResultSet can't support, build the full Collection. Jeff Schnitzer [EMAIL PROTECTED] _ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx
RE: CMP 2.0 vs BMP - Which performes better?
See my earlier post on this thread. You can use custom finders with _extreme_ ease in Orion. I gave an example for Oracle (since Oracle does not _have_ the sql LIMIT statement). For other databases, you could use a LIMIT statement in your custom finder. Regards, the elephantwalker www.elephantwalker.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of prasanth sb Sent: Friday, April 05, 2002 7:20 AM To: Orion-Interest Subject: RE: CMP 2.0 vs BMP - Which performes better? Hi Jeff and other dear friends, I had this doubt in my mind very earlier. When we load very large amount of data from the database, how it can be handled? If we use result sets and iterate, this is going to take a long time? How can we limit the number of records that is present in the memory at a time? thanks, Prasanth. From: Jeff Schnitzer [EMAIL PROTECTED] Reply-To: Orion-Interest [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Subject: RE: CMP 2.0 vs BMP - Which performes better? Date: Thu, 4 Apr 2002 16:22:17 -0800 From: Curt Smith [mailto:[EMAIL PROTECTED]] There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. I'd like to know more of the details? How does the container deal with the following finder in CMP differently than BMP? Collection remoteRefs = home.findSalaryGreaterThan ( 50,000); Lets assume this produces 1000 results which you then iterate through. With BMP beans, this will require 1001 database queries. First the finder, then 1000 selects to load each bean. With CMP, it's actually rather ambiguous what will happen. Last time I checked, Orion will load all the beans into an ArrayList. Yes, lots of memory consumed, but a *lot* better than 1001 database hits. Admittedly a bigger problem with orders of magnitude more objects, but even with BMP you're going to choke if the finder query returns a billion rows of primary key data. Some containers (not Orion, I don't think) allow you to specify that finders should lazy-load beans. But this brings you back to BMP performance. Some containers allow you to define field groups to minimize the amount of data brought back (especially useful if you store blobs), but not Orion. Personally, I don't understand why containers don't implement Collections backed by the ResultSet directly. 98% of the time, the client just creates an iterator and walks the results. If the client does something that the ResultSet can't support, build the full Collection. Jeff Schnitzer [EMAIL PROTECTED] _ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx
RE: CMP 2.0 vs BMP - Which performes better?
Hi elephantwalker, A big thanks for the help. This is a great support from elephantwalker with quick replies.God bless. thanks, Prasanth. From: The elephantwalker [EMAIL PROTECTED] Reply-To: Orion-Interest [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Subject: RE: CMP 2.0 vs BMP - Which performes better? Date: Fri, 5 Apr 2002 11:54:00 -0800 See my earlier post on this thread. You can use custom finders with _extreme_ ease in Orion. I gave an example for Oracle (since Oracle does not _have_ the sql LIMIT statement). For other databases, you could use a LIMIT statement in your custom finder. Regards, the elephantwalker www.elephantwalker.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of prasanth sb Sent: Friday, April 05, 2002 7:20 AM To: Orion-Interest Subject: RE: CMP 2.0 vs BMP - Which performes better? Hi Jeff and other dear friends, I had this doubt in my mind very earlier. When we load very large amount of data from the database, how it can be handled? If we use result sets and iterate, this is going to take a long time? How can we limit the number of records that is present in the memory at a time? thanks, Prasanth. From: Jeff Schnitzer [EMAIL PROTECTED] Reply-To: Orion-Interest [EMAIL PROTECTED] To: Orion-Interest [EMAIL PROTECTED] Subject: RE: CMP 2.0 vs BMP - Which performes better? Date: Thu, 4 Apr 2002 16:22:17 -0800 From: Curt Smith [mailto:[EMAIL PROTECTED]] There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. I'd like to know more of the details? How does the container deal with the following finder in CMP differently than BMP? Collection remoteRefs = home.findSalaryGreaterThan ( 50,000); Lets assume this produces 1000 results which you then iterate through. With BMP beans, this will require 1001 database queries. First the finder, then 1000 selects to load each bean. With CMP, it's actually rather ambiguous what will happen. Last time I checked, Orion will load all the beans into an ArrayList. Yes, lots of memory consumed, but a *lot* better than 1001 database hits. Admittedly a bigger problem with orders of magnitude more objects, but even with BMP you're going to choke if the finder query returns a billion rows of primary key data. Some containers (not Orion, I don't think) allow you to specify that finders should lazy-load beans. But this brings you back to BMP performance. Some containers allow you to define field groups to minimize the amount of data brought back (especially useful if you store blobs), but not Orion. Personally, I don't understand why containers don't implement Collections backed by the ResultSet directly. 98% of the time, the client just creates an iterator and walks the results. If the client does something that the ResultSet can't support, build the full Collection. Jeff Schnitzer [EMAIL PROTECTED] _ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx _ Send and receive Hotmail on your mobile device: http://mobile.msn.com
Re: CMP 2.0 vs BMP - Which performes better?
There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. I'd like to know more of the details? How does the container deal with the following finder in CMP differently than BMP? Collection remoteRefs = home.findSalaryGreaterThan ( 50,000); Or what was the scenario you where refering to? To me the finder returns a collection problem is but one of the damning EJB achilies heals, in that the spec left out setting the max row count to limit the find collection to. How does CMP help the huge memory and CPU and JNDI hit that a boundless findAll() causes? Thanks, curt
RE: CMP 2.0 vs BMP - Which performes better?
Curt, I don't know anybody that uses the vanilla findAll() in a cmp finder. In orion, it is _extremely_ easy to add a customer finder findAll that has a limit. Here is my findAll for Oracle(oracle doesn't have LIMIT): finder-method partial=false query=select * from (select a.*, rownum rn from (select somebean.* from somebean order by somebean.lastmodified desc) a where rownum lt; ($1 + $2) ) where rn gt;= $1 method ejb-namesomebean/ejb-name method-namefindAll/method-name method-params method-paramint/method-param method-paramint/method-param /method-params /method /finder-method You could likewise use a stored procedure in the finder-method for even greater speed. With these finders, cmp _rocks_! regards, the elephantwalker www.elephantwalker.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Curt Smith Sent: Thursday, April 04, 2002 9:21 AM To: Orion-Interest Subject: Re: CMP 2.0 vs BMP - Which performes better? There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. I'd like to know more of the details? How does the container deal with the following finder in CMP differently than BMP? Collection remoteRefs = home.findSalaryGreaterThan ( 50,000); Or what was the scenario you where refering to? To me the finder returns a collection problem is but one of the damning EJB achilies heals, in that the spec left out setting the max row count to limit the find collection to. How does CMP help the huge memory and CPU and JNDI hit that a boundless findAll() causes? Thanks, curt
Re: [orion-interest]RE: CMP 2.0 vs BMP - Which performes better?
Some caveats for the approach below: - DB specified, rownum is an Oracle thing - select * will bite you in the ass if your table structure ever changes There are actually approaches for doing a limit type finder, using a poll/seek algorithm... On 4/4/02 4:59 pm, The elephantwalker [EMAIL PROTECTED] wrote: Curt, I don't know anybody that uses the vanilla findAll() in a cmp finder. In orion, it is _extremely_ easy to add a customer finder findAll that has a limit. Here is my findAll for Oracle(oracle doesn't have LIMIT): finder-method partial=false query=select * from (select a.*, rownum rn from (select somebean.* from somebean order by somebean.lastmodified desc) a where rownum lt; ($1 + $2) ) where rn gt;= $1 method ejb-namesomebean/ejb-name method-namefindAll/method-name method-params method-paramint/method-param method-paramint/method-param /method-params /method /finder-method You could likewise use a stored procedure in the finder-method for even greater speed. With these finders, cmp _rocks_! regards, the elephantwalker www.elephantwalker.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Curt Smith Sent: Thursday, April 04, 2002 9:21 AM To: Orion-Interest Subject: Re: CMP 2.0 vs BMP - Which performes better? There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. I'd like to know more of the details? How does the container deal with the following finder in CMP differently than BMP? Collection remoteRefs = home.findSalaryGreaterThan ( 50,000); Or what was the scenario you where refering to? To me the finder returns a collection problem is but one of the damning EJB achilies heals, in that the spec left out setting the max row count to limit the find collection to. How does CMP help the huge memory and CPU and JNDI hit that a boundless findAll() causes? Thanks, curt
RE: CMP 2.0 vs BMP - Which performes better?
From: Curt Smith [mailto:[EMAIL PROTECTED]] There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. I'd like to know more of the details? How does the container deal with the following finder in CMP differently than BMP? Collection remoteRefs = home.findSalaryGreaterThan ( 50,000); Lets assume this produces 1000 results which you then iterate through. With BMP beans, this will require 1001 database queries. First the finder, then 1000 selects to load each bean. With CMP, it's actually rather ambiguous what will happen. Last time I checked, Orion will load all the beans into an ArrayList. Yes, lots of memory consumed, but a *lot* better than 1001 database hits. Admittedly a bigger problem with orders of magnitude more objects, but even with BMP you're going to choke if the finder query returns a billion rows of primary key data. Some containers (not Orion, I don't think) allow you to specify that finders should lazy-load beans. But this brings you back to BMP performance. Some containers allow you to define field groups to minimize the amount of data brought back (especially useful if you store blobs), but not Orion. Personally, I don't understand why containers don't implement Collections backed by the ResultSet directly. 98% of the time, the client just creates an iterator and walks the results. If the client does something that the ResultSet can't support, build the full Collection. Jeff Schnitzer [EMAIL PROTECTED]
RE: CMP 2.0 vs BMP - Which performes better?
Huh? There are several constraints to BMP beans which make them almost always perform slower than CMP beans. In particular, the inability to bulk load beans from finder methods is a nearly fatal defect. In general, I recommend a combination of CMP entities and raw JDBC in session beans for queries that are not efficient or possible in a CMP environment. Just watch out for relationships in Orion. They are horribly broken, have been for years, and don't show any sign of getting better. Jeff Schnitzer [EMAIL PROTECTED] -Original Message- From: Andrew Chau [mailto:[EMAIL PROTECTED]] Sent: Friday, March 29, 2002 6:11 PM To: Orion-Interest Subject: RE: CMP 2.0 vs BMP - Which performes better? If performance is the only factor, BMP performs a million times faster than CMP. Well, may be not that much faster, but you get the point. CMP is for ease of development, basically the container does all the work for you, but it is not as flexible and you cannot fine tune the query like you can do in BMP. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Orion Newsgroup Sent: Thursday, March 28, 2002 2:40 PM To: Orion-Interest Subject: CMP 2.0 vs BMP - Which performes better? Subject: CMP 2.0 vs BMP - Which performes better? From: alt.cybercafes [EMAIL PROTECTED] === I am in the process of building a database intensive app and wanted to know whether to use container manage persistance versus bean manage persistence for this database instensive application. What are the pros and cons of CMP and BMP.? thanks
RE: CMP 2.0 vs BMP - Which performes better?
If performance is the only factor, BMP performs a million times faster than CMP. Well, may be not that much faster, but you get the point. CMP is for ease of development, basically the container does all the work for you, but it is not as flexible and you cannot fine tune the query like you can do in BMP. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Orion Newsgroup Sent: Thursday, March 28, 2002 2:40 PM To: Orion-Interest Subject: CMP 2.0 vs BMP - Which performes better? Subject: CMP 2.0 vs BMP - Which performes better? From: alt.cybercafes [EMAIL PROTECTED] === I am in the process of building a database intensive app and wanted to know whether to use container manage persistance versus bean manage persistence for this database instensive application. What are the pros and cons of CMP and BMP.? thanks
