You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@ofbiz.apache.org by Jacques Le Roux <ja...@les7arts.com> on 2012/05/20 11:01:46 UTC
Slim-down continue [was Re: svn commit: r1340414 - ...]
Quick questions (seems that there is a lack of internal documentation to say the least), there are not only addressed to Adam...
About javacc dependency do we really need it *OOTB*?
Can't we use rather externally maintained ant targets like in ant-contrib? For instance pleaser read
http://markmail.org/message/lidw73cuzyfr6cic
What is framework\sql used for *OOTB*?
What is the jjtree task used for *OOTB*?
In other words what are the benefits for the Apache OFBiz projet from those marvellous pieces of code (a "bit" undocumented though)
Jacques
PS : you can refer to https://issues.apache.org/jira/browse/OFBIZ-4833: "Housekeeping of jar files"
From: "Jacques Le Roux" <ja...@les7arts.com>
> From: "Adam Heath" <do...@brainfood.com>
>> And, this commit was done wrong in the first place. If you remove a library, remove it's entry from *all* locations, including
>> NOTICE, LICENSE, build.xml(s). Do a grep on it's name.
>
> Indeed
>
>> In addition, each library removal should have been done as a *separate* change, not all bundled like this. Separate allows for
>> debugging things when something goes wrong in the future, and one has to revert back to previous versions to figure it out(also
>> known as git bisect).
>
> Right
>
> Jacques
>
>> On 05/19/2012 07:24 PM, Scott Gray wrote:
>>> +1, I'm really sick and tired of this Jacques. The lack of care shown in obvious places like this makes me very concerned about
>>> all of your commits in general, I really don't want to have to start closely reviewing every single one. Given that you are
>>> OFBiz's most prolific committer by a large margin, you're taking time away from the other committers by forcing us to review all
>>> of your work and that's just not fair. I regularly see basic problems with your commits but I just don't have the energy to
>>> respond most of the time unless it's obviously going to break something.
>>>
>>> Before committing please just stop and ask yourself a few questions:
>>> - Do I fully understand the problem I'm about to try and solve?
>>> - Have a taken all practical steps to ensure this change won't break anything?
>>> - Is this the best solution to the problem?
>>>
>>> If the answer to any of the above is no then just stop, wait, think and discuss.
>>>
>>> Thanks
>>> Scott
>>>
>>> On 20/05/2012, at 12:52 AM, Adrian Crum wrote:
>>>
>>>> Jacques,
>>>>
>>>> I am going to repeat what Scott said the other day:
>>>>
>>>> Before you commit, run ant clean-all load-demo run-tests.
>>>>
>>>> This lack of care in the commit process needs to stop.
>>>>
>>>> -Adrian
>>>>
>>>> On 5/19/2012 1:41 PM, Adrian Crum wrote:
>>>>> The project will not compile after this change.
>>>>>
>>>>> -Adrian
>>>>>
>>>>> On 5/19/2012 11:57 AM, jleroux@apache.org wrote:
>>>>>> Author: jleroux
>>>>>> Date: Sat May 19 10:57:40 2012
>>>>>> New Revision: 1340414
>>>>>>
>>>>>> URL: http://svn.apache.org/viewvc?rev=1340414&view=rev
>>>>>> Log:
>>>>>> Following
>>>>>> https://issues.apache.org/jira/browse/OFBIZ-4833?focusedCommentId=13275249&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13275249
>>>>>> Moves to Attic:
>>>>>> framework/base/lib/ant/ant-nodeps-1.8.1.jar => can be removed IMO. It was added with ant 1.8 by Hans, not sure why (no
>>>>>> comment about need), seems to contains no needed stuff
>>>>>> framework/base/lib/javacc can be removed IMO. The Java Compiler Compiler tm (JavaCC tm) - The Java Parser Generator, not
>>>>>> used OOTB, was added by Marco, not sure why (no comment about need)
>>>>>> framework/base/lib/Tidy.jar was used at bottom of eCommerce pages before, no longer needed
>>>>>> framework/base/lib/ant-trax-1.8.0.jar can be removed IMO. It was added with ant 1.8 by Hans, not sure why (no comment
>>>>>> about need), contains XSLT task
>>>>>> framework/base/lib/commons/commons-vfs-20070730.jar certainly added with Webslinger can be removed now
>>>>>>
>>>>>> Removed:
>>>>>> ofbiz/trunk/framework/base/lib/Tidy.jar
>>>>>> ofbiz/trunk/framework/base/lib/ant-trax-1.8.0.jar
>>>>>> ofbiz/trunk/framework/base/lib/ant/ant-nodeps-1.8.1.jar
>>>>>> ofbiz/trunk/framework/base/lib/commons/commons-vfs-20070730.jar
>>>>>> ofbiz/trunk/framework/base/lib/javacc/
>>>>>> ofbiz/trunk/lib/
>>>>>>
>>>
>>
>
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Jacques Le Roux <ja...@les7arts.com>.
Thanks Adrian
Jacques
From: "Adrian Crum" <ad...@sandglass-software.com>
> On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
>> Quick questions (seems that there is a lack of internal documentation
>> to say the least), there are not only addressed to Adam...
>>
>> About javacc dependency do we really need it *OOTB*?
>> Can't we use rather externally maintained ant targets like in
>> ant-contrib? For instance pleaser read
>> http://markmail.org/message/lidw73cuzyfr6cic
>>
>> What is framework\sql used for *OOTB*?
>
> From what I understand, the sql component parses SQL statements into
> OFBiz entity conditions, and then executes the statement using the
> entity engine. I don't think it is used OOTB for anything, but it could
> be useful for integration with third-party libraries that take SQL
> statements - like Jasper Reports.
>
> -Adrian
>
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Jacques Le Roux <ja...@les7arts.com>.
From: "Adam Heath" <do...@brainfood.com>
> On 05/24/2012 04:05 PM, Jacques Le Roux wrote:
>> From: "Adam Heath" <do...@brainfood.com>
>>> On 05/24/2012 10:18 AM, Adam Heath wrote:
>>>> On 05/24/2012 08:15 AM, Adrian Crum wrote:
>>>>> On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
>>>>>> Quick questions (seems that there is a lack of internal
>>>>>> documentation to say the least), there are not only addressed to
>>>>>> Adam...
>>>>>>
>>>>>> About javacc dependency do we really need it *OOTB*?
>>>>>> Can't we use rather externally maintained ant targets like in
>>>>>> ant-contrib? For instance pleaser read
>>>>>> http://markmail.org/message/lidw73cuzyfr6cic
>>>>>>
>>>>>> What is framework\sql used for *OOTB*?
>>>>>
>>>>> From what I understand, the sql component parses SQL statements into
>>>>> OFBiz entity conditions, and then executes the statement using the
>>>>> entity engine. I don't think it is used OOTB for anything, but it
>>>>> could be useful for integration with third-party libraries that take
>>>>> SQL statements - like Jasper Reports.
>>>>
>>>> You can also parse *raw* where clauses.
>>>>
>>>> ==
>>>> import org.ofbiz.sql.Parser;
>>>> import org.ofbiz.entity.sql.EntityPlanner;
>>>>
>>>> String sqlConditionString = "contactMechId = ?contactMechId";
>>>>
>>>> def sqlPlanner = new EntityPlanner();
>>>> def reader = new StringReader(sqlCondition);
>>>> def sqlCondition = new Parser(reader).EntityCondition();
>>>>
>>>> while (true) {
>>>> def condition = sqlPlanner.getConditionPlanner().parse(sqlCondition,
>>>> [contactMechId: '1']);
>>>> delegator.findList(entityName, condition, ....)
>>>> }
>>>> ==
>>>>
>>>> I suppose I should place some of that in a util class(SQLUtil comes to
>>>> mind, it was never finished).
>>>>
>>>> I support (), and, or, in, between, it's rather complete.
>>>
>>> The idea was that you would parse the sqlCondition once, in a static
>>> {} block somewhere, then at runtime, just build that map. This
>>> builds-upon the map/list idea inherent in ofbiz.
>>>
>>> I also had plans that you could store sql strings into a properties
>>> file somewhere, so that they could possibly be changed by the end-user
>>> without having to recompile.
>>>
>>> I need to revisit the "SELECT a.partyId, b.* EXCLUDE(partyId) FROM
>>> Party a LEFT JOIN PartyContactMech b USING (partyId)", now that ofbiz
>>> better supports conditions on the join clauses, esp. when combining
>>> views into other views.
>>
>> Thanks for the explanation,
>>
>> So should we not rather create a Jira with all the needed in a patch
>> until this is finished?
>> Or maybe a branch would be easier?
>>
>> Still with the slim-down idea in mind and as objective.
>
> I like the slimdown, but tbh, I would like to see the framework/sql stuff used more than it is(0 right now). Andrew Zeneski was
> an original requestor for something that parsed sql into EntityCondition. I took his suggestion, but went further, to allow
> CREATE VIEW AS SELECT to work.
>
> I've noticed that there aren't that many view definitions in ofbiz. As I've been deprecating all this code recently, I've noticed
> java code doing nested loop kinda-stuff, instead of just doing a view. I'm guessing because view-xml is verbose and not how
> people actually think.
>
> However, with what I committed, you can define the view using a SQL syntax, which is then backed by a DynamicViewEntity.
>
> I've seen rather impressive speedups just rewriting code to a single SQL query, instead of java loops; the database can be rather
> efficient. So making view writing simpler is a laudable goal.
Great, but still, why not a branch as long as it's not finished?
Also something which I think is pretty neat in the principle (I still did not review the code) and would speed up views:
https://issues.apache.org/jira/browse/OFBIZ-4041
Jacques
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Pierre Smits <pi...@gmail.com>.
May be doing a little example code that shows how it works and the
performance impact can help developers with implementation in various areas.
Regards,
Pierre
2012/5/25 Adam Heath <do...@brainfood.com>
> On 05/24/2012 04:05 PM, Jacques Le Roux wrote:
>
>> From: "Adam Heath" <do...@brainfood.com>
>>
>>> On 05/24/2012 10:18 AM, Adam Heath wrote:
>>>
>>>> On 05/24/2012 08:15 AM, Adrian Crum wrote:
>>>>
>>>>> On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
>>>>>
>>>>>> Quick questions (seems that there is a lack of internal
>>>>>> documentation to say the least), there are not only addressed to
>>>>>> Adam...
>>>>>>
>>>>>> About javacc dependency do we really need it *OOTB*?
>>>>>> Can't we use rather externally maintained ant targets like in
>>>>>> ant-contrib? For instance pleaser read
>>>>>> http://markmail.org/message/**lidw73cuzyfr6cic<http://markmail.org/message/lidw73cuzyfr6cic>
>>>>>>
>>>>>> What is framework\sql used for *OOTB*?
>>>>>>
>>>>>
>>>>> From what I understand, the sql component parses SQL statements into
>>>>> OFBiz entity conditions, and then executes the statement using the
>>>>> entity engine. I don't think it is used OOTB for anything, but it
>>>>> could be useful for integration with third-party libraries that take
>>>>> SQL statements - like Jasper Reports.
>>>>>
>>>>
>>>> You can also parse *raw* where clauses.
>>>>
>>>> ==
>>>> import org.ofbiz.sql.Parser;
>>>> import org.ofbiz.entity.sql.**EntityPlanner;
>>>>
>>>> String sqlConditionString = "contactMechId = ?contactMechId";
>>>>
>>>> def sqlPlanner = new EntityPlanner();
>>>> def reader = new StringReader(sqlCondition);
>>>> def sqlCondition = new Parser(reader).**EntityCondition();
>>>>
>>>> while (true) {
>>>> def condition = sqlPlanner.**getConditionPlanner().parse(**
>>>> sqlCondition,
>>>> [contactMechId: '1']);
>>>> delegator.findList(entityName, condition, ....)
>>>> }
>>>> ==
>>>>
>>>> I suppose I should place some of that in a util class(SQLUtil comes to
>>>> mind, it was never finished).
>>>>
>>>> I support (), and, or, in, between, it's rather complete.
>>>>
>>>
>>> The idea was that you would parse the sqlCondition once, in a static
>>> {} block somewhere, then at runtime, just build that map. This
>>> builds-upon the map/list idea inherent in ofbiz.
>>>
>>> I also had plans that you could store sql strings into a properties
>>> file somewhere, so that they could possibly be changed by the end-user
>>> without having to recompile.
>>>
>>> I need to revisit the "SELECT a.partyId, b.* EXCLUDE(partyId) FROM
>>> Party a LEFT JOIN PartyContactMech b USING (partyId)", now that ofbiz
>>> better supports conditions on the join clauses, esp. when combining
>>> views into other views.
>>>
>>
>> Thanks for the explanation,
>>
>> So should we not rather create a Jira with all the needed in a patch
>> until this is finished?
>> Or maybe a branch would be easier?
>>
>> Still with the slim-down idea in mind and as objective.
>>
>
> I like the slimdown, but tbh, I would like to see the framework/sql stuff
> used more than it is(0 right now). Andrew Zeneski was an original
> requestor for something that parsed sql into EntityCondition. I took his
> suggestion, but went further, to allow CREATE VIEW AS SELECT to work.
>
> I've noticed that there aren't that many view definitions in ofbiz. As
> I've been deprecating all this code recently, I've noticed java code doing
> nested loop kinda-stuff, instead of just doing a view. I'm guessing
> because view-xml is verbose and not how people actually think.
>
> However, with what I committed, you can define the view using a SQL
> syntax, which is then backed by a DynamicViewEntity.
>
> I've seen rather impressive speedups just rewriting code to a single SQL
> query, instead of java loops; the database can be rather efficient. So
> making view writing simpler is a laudable goal.
>
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Adam Heath <do...@brainfood.com>.
On 05/24/2012 04:05 PM, Jacques Le Roux wrote:
> From: "Adam Heath" <do...@brainfood.com>
>> On 05/24/2012 10:18 AM, Adam Heath wrote:
>>> On 05/24/2012 08:15 AM, Adrian Crum wrote:
>>>> On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
>>>>> Quick questions (seems that there is a lack of internal
>>>>> documentation to say the least), there are not only addressed to
>>>>> Adam...
>>>>>
>>>>> About javacc dependency do we really need it *OOTB*?
>>>>> Can't we use rather externally maintained ant targets like in
>>>>> ant-contrib? For instance pleaser read
>>>>> http://markmail.org/message/lidw73cuzyfr6cic
>>>>>
>>>>> What is framework\sql used for *OOTB*?
>>>>
>>>> From what I understand, the sql component parses SQL statements into
>>>> OFBiz entity conditions, and then executes the statement using the
>>>> entity engine. I don't think it is used OOTB for anything, but it
>>>> could be useful for integration with third-party libraries that take
>>>> SQL statements - like Jasper Reports.
>>>
>>> You can also parse *raw* where clauses.
>>>
>>> ==
>>> import org.ofbiz.sql.Parser;
>>> import org.ofbiz.entity.sql.EntityPlanner;
>>>
>>> String sqlConditionString = "contactMechId = ?contactMechId";
>>>
>>> def sqlPlanner = new EntityPlanner();
>>> def reader = new StringReader(sqlCondition);
>>> def sqlCondition = new Parser(reader).EntityCondition();
>>>
>>> while (true) {
>>> def condition = sqlPlanner.getConditionPlanner().parse(sqlCondition,
>>> [contactMechId: '1']);
>>> delegator.findList(entityName, condition, ....)
>>> }
>>> ==
>>>
>>> I suppose I should place some of that in a util class(SQLUtil comes to
>>> mind, it was never finished).
>>>
>>> I support (), and, or, in, between, it's rather complete.
>>
>> The idea was that you would parse the sqlCondition once, in a static
>> {} block somewhere, then at runtime, just build that map. This
>> builds-upon the map/list idea inherent in ofbiz.
>>
>> I also had plans that you could store sql strings into a properties
>> file somewhere, so that they could possibly be changed by the end-user
>> without having to recompile.
>>
>> I need to revisit the "SELECT a.partyId, b.* EXCLUDE(partyId) FROM
>> Party a LEFT JOIN PartyContactMech b USING (partyId)", now that ofbiz
>> better supports conditions on the join clauses, esp. when combining
>> views into other views.
>
> Thanks for the explanation,
>
> So should we not rather create a Jira with all the needed in a patch
> until this is finished?
> Or maybe a branch would be easier?
>
> Still with the slim-down idea in mind and as objective.
I like the slimdown, but tbh, I would like to see the framework/sql
stuff used more than it is(0 right now). Andrew Zeneski was an original
requestor for something that parsed sql into EntityCondition. I took
his suggestion, but went further, to allow CREATE VIEW AS SELECT to work.
I've noticed that there aren't that many view definitions in ofbiz. As
I've been deprecating all this code recently, I've noticed java code
doing nested loop kinda-stuff, instead of just doing a view. I'm
guessing because view-xml is verbose and not how people actually think.
However, with what I committed, you can define the view using a SQL
syntax, which is then backed by a DynamicViewEntity.
I've seen rather impressive speedups just rewriting code to a single SQL
query, instead of java loops; the database can be rather efficient. So
making view writing simpler is a laudable goal.
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Jacques Le Roux <ja...@les7arts.com>.
From: "Adam Heath" <do...@brainfood.com>
> On 05/24/2012 10:18 AM, Adam Heath wrote:
>> On 05/24/2012 08:15 AM, Adrian Crum wrote:
>>> On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
>>>> Quick questions (seems that there is a lack of internal
>>>> documentation to say the least), there are not only addressed to
>>>> Adam...
>>>>
>>>> About javacc dependency do we really need it *OOTB*?
>>>> Can't we use rather externally maintained ant targets like in
>>>> ant-contrib? For instance pleaser read
>>>> http://markmail.org/message/lidw73cuzyfr6cic
>>>>
>>>> What is framework\sql used for *OOTB*?
>>>
>>> From what I understand, the sql component parses SQL statements into
>>> OFBiz entity conditions, and then executes the statement using the
>>> entity engine. I don't think it is used OOTB for anything, but it
>>> could be useful for integration with third-party libraries that take
>>> SQL statements - like Jasper Reports.
>>
>> You can also parse *raw* where clauses.
>>
>> ==
>> import org.ofbiz.sql.Parser;
>> import org.ofbiz.entity.sql.EntityPlanner;
>>
>> String sqlConditionString = "contactMechId = ?contactMechId";
>>
>> def sqlPlanner = new EntityPlanner();
>> def reader = new StringReader(sqlCondition);
>> def sqlCondition = new Parser(reader).EntityCondition();
>>
>> while (true) {
>> def condition = sqlPlanner.getConditionPlanner().parse(sqlCondition,
>> [contactMechId: '1']);
>> delegator.findList(entityName, condition, ....)
>> }
>> ==
>>
>> I suppose I should place some of that in a util class(SQLUtil comes to
>> mind, it was never finished).
>>
>> I support (), and, or, in, between, it's rather complete.
>
> The idea was that you would parse the sqlCondition once, in a static
> {} block somewhere, then at runtime, just build that map. This
> builds-upon the map/list idea inherent in ofbiz.
>
> I also had plans that you could store sql strings into a properties
> file somewhere, so that they could possibly be changed by the end-user
> without having to recompile.
>
> I need to revisit the "SELECT a.partyId, b.* EXCLUDE(partyId) FROM
> Party a LEFT JOIN PartyContactMech b USING (partyId)", now that ofbiz
> better supports conditions on the join clauses, esp. when combining
> views into other views.
Thanks for the explanation,
So should we not rather create a Jira with all the needed in a patch until this is finished?
Or maybe a branch would be easier?
Still with the slim-down idea in mind and as objective.
Jacques
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Adam Heath <do...@brainfood.com>.
On 05/24/2012 10:18 AM, Adam Heath wrote:
> On 05/24/2012 08:15 AM, Adrian Crum wrote:
>> On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
>>> Quick questions (seems that there is a lack of internal
>>> documentation to say the least), there are not only addressed to
>>> Adam...
>>>
>>> About javacc dependency do we really need it *OOTB*?
>>> Can't we use rather externally maintained ant targets like in
>>> ant-contrib? For instance pleaser read
>>> http://markmail.org/message/lidw73cuzyfr6cic
>>>
>>> What is framework\sql used for *OOTB*?
>>
>> From what I understand, the sql component parses SQL statements into
>> OFBiz entity conditions, and then executes the statement using the
>> entity engine. I don't think it is used OOTB for anything, but it
>> could be useful for integration with third-party libraries that take
>> SQL statements - like Jasper Reports.
>
> You can also parse *raw* where clauses.
>
> ==
> import org.ofbiz.sql.Parser;
> import org.ofbiz.entity.sql.EntityPlanner;
>
> String sqlConditionString = "contactMechId = ?contactMechId";
>
> def sqlPlanner = new EntityPlanner();
> def reader = new StringReader(sqlCondition);
> def sqlCondition = new Parser(reader).EntityCondition();
>
> while (true) {
> def condition = sqlPlanner.getConditionPlanner().parse(sqlCondition,
> [contactMechId: '1']);
> delegator.findList(entityName, condition, ....)
> }
> ==
>
> I suppose I should place some of that in a util class(SQLUtil comes to
> mind, it was never finished).
>
> I support (), and, or, in, between, it's rather complete.
The idea was that you would parse the sqlCondition once, in a static
{} block somewhere, then at runtime, just build that map. This
builds-upon the map/list idea inherent in ofbiz.
I also had plans that you could store sql strings into a properties
file somewhere, so that they could possibly be changed by the end-user
without having to recompile.
I need to revisit the "SELECT a.partyId, b.* EXCLUDE(partyId) FROM
Party a LEFT JOIN PartyContactMech b USING (partyId)", now that ofbiz
better supports conditions on the join clauses, esp. when combining
views into other views.
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Adam Heath <do...@brainfood.com>.
On 05/24/2012 08:15 AM, Adrian Crum wrote:
> On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
>> Quick questions (seems that there is a lack of internal
>> documentation to say the least), there are not only addressed to
>> Adam...
>>
>> About javacc dependency do we really need it *OOTB*?
>> Can't we use rather externally maintained ant targets like in
>> ant-contrib? For instance pleaser read
>> http://markmail.org/message/lidw73cuzyfr6cic
>>
>> What is framework\sql used for *OOTB*?
>
> From what I understand, the sql component parses SQL statements into
> OFBiz entity conditions, and then executes the statement using the
> entity engine. I don't think it is used OOTB for anything, but it
> could be useful for integration with third-party libraries that take
> SQL statements - like Jasper Reports.
You can also parse *raw* where clauses.
==
import org.ofbiz.sql.Parser;
import org.ofbiz.entity.sql.EntityPlanner;
String sqlConditionString = "contactMechId = ?contactMechId";
def sqlPlanner = new EntityPlanner();
def reader = new StringReader(sqlCondition);
def sqlCondition = new Parser(reader).EntityCondition();
while (true) {
def condition = sqlPlanner.getConditionPlanner().parse(sqlCondition,
[contactMechId: '1']);
delegator.findList(entityName, condition, ....)
}
==
I suppose I should place some of that in a util class(SQLUtil comes to
mind, it was never finished).
I support (), and, or, in, between, it's rather complete.
Re: Slim-down continue [was Re: svn commit: r1340414 - ...]
Posted by Adrian Crum <ad...@sandglass-software.com>.
On 5/20/2012 10:01 AM, Jacques Le Roux wrote:
> Quick questions (seems that there is a lack of internal documentation
> to say the least), there are not only addressed to Adam...
>
> About javacc dependency do we really need it *OOTB*?
> Can't we use rather externally maintained ant targets like in
> ant-contrib? For instance pleaser read
> http://markmail.org/message/lidw73cuzyfr6cic
>
> What is framework\sql used for *OOTB*?
From what I understand, the sql component parses SQL statements into
OFBiz entity conditions, and then executes the statement using the
entity engine. I don't think it is used OOTB for anything, but it could
be useful for integration with third-party libraries that take SQL
statements - like Jasper Reports.
-Adrian