I have a spring project with many Entities and a complex relationship between entities. I would like to automatically find the indexes that are missing so that I could create those indexes. Are there any tools that help in achieving this? We are using Hibernate ORM and Oracle Database.
There is a new useful feature in Hibernate: SLOW_QUERY_LOG(LOG_QUERIES_SLOWER_THAN_MS). It would help you if it really worked (HHH-13928)
There is cool (but very expensive) tool Dynatrace, which can tell you relation between a slow REST API call and particular slow SQL
And then there are Oracle's native tools like Diagnostic pack and Tunning pack. But those will not show you relation between slow SQL and piece in you code which called it.
There is common issued when there are missing indexes on FK keys. In most cases those are a must. https://www.orafaq.com/node/2935
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Is Entity Framework 4.1 is the best solution for a web application that is using almost 400 database tables or it would best to make cutome data access layer with straight sql and sp?
The number of tables only affects EF initialization where "views" must be compiled when the context is used first time in the application - 400 is a lot and it will take a lot of time. This can be speed up by generating source code for views and adding these source codes to the project - views will not be compiled at runtime because compiled code will be part of your application but you must manually do this each time you change the model. For EFv4.1 this feature is offered in EF Power Tools CTP1. For EDMX the feature is offered in EdmGen command line tool.
Another impact on such number of tables in on development. Using 400 tables in single EDMX seems impossible so you will need multiple contexts with different sets of mapped entities. This can be complex task for application architecture because working with multiple contexts makes everything harder.
If you want to use code only mapping you must either write classes and mapping for 400 tables or you will again use EF Power Tools CTP1 which will generate them for you.
It is not impossible to use EF with 400 tables but it is complex and requires some experience.
Different people may have different views on it. Answer to your question is how you use EF whether it will be poco model or you are going to use edmx? EF performance depends on the number of records as well, so if you are using 10 tables and altogether they have 100 records then ef will perform better.
But still performance of ef on the basis of tables and records is a big question and it depends on various factors including your database designing whether it is properly normalised or not.
We do have more than 1000 tables, and we are using it (its a web app). You do not have to put everything in a single model, that would make it pretty darn hard to work on the model itself. And we are using Code Only approach, its in development yet, but everything works fine so far.
As a predefined conditions I have multiple database sources to deal with.
Also I have a UDT – user defined types objects in part of this databases ( the UDT’s also have children inside) .
As a methodology I am a believer of using the ORM-object relational mapping to connect to DB’s .
In the past I’ve successfully implemented Fluent NHibernate library to connect to Oracle.
I’ve found a workaround for the Multiple Databases , even though the solution may be more elegant in future.
Nevertheless , I still can’t find a solution for mapping the UDT’s .
I think that it should be something like implementation of IUserType or ICompositeUserType .
If there is a known framework presenting option for a full ORM , including UDT’s handle it also can be a solution in our case.
I’ve checked out the EF of oracle (that is very premature) and also DevArt (that doesn’t handle UDT’s) as a possible solutions.
The ODP.Net is the only possible way right now and it’s not too friendly for the developers to use – no LINQ support , no context to begin with.
If you or any of your colleagues can help with some samples of the implementation of this kind of mapping it will be very appreciated.
I feel your pain, working with ODP.NET is not a pleasant experience at all. DevArt dotConnect supports UDT's. DevArt Objects documentation
A question of ColdFusion ORM
We are using ColdFusion 9 for the past 6 months and while we've used some of the new features, ORM is something we've avoided because we usually work on the same very large website. Over the years we've used Apache OBJ but then we moved back to CF and used our own DAO objects generated from tables to handle basic CRUD. These objects are basic and need to be regenerated manually for schema changes and do not model table relationships at all. To supplement these we have a set of gateway classes for multi-table queries. While all this is very bespoke, these DAOs and gateways do, however, give us great control over the SQL we execute, for example using locking hints and optimiser hints. Our site is busy but our database is very efficient.
So much for the history lesson: the point of this is that we have a new site upcoming soon that will be written from scratch to handle financial transactions. We would normally use our aforementioned DAO objects to handle CRUD and then the usual set of gateway objects for multi-table joins but I thought we might investigate using baked-in CF ORM...
So with that in mind, I'd love to hear of the lessons, tips and tricks others might have to share in regard to using ORM on a busy financial site. For example:
What's the best way to flush your SQL ? What tips do you have for transactional ORM? How do you setup development and live sites for ORM? What about HQL? When should we just do the SQL ourselves by hand?!
Thanks in advance!
Short answer, YES! go for ORM!!!
What's the best way to flush your SQL ?
ormflush()
What tips do you have for transactional ORM?
<cftransaction> or transaction {} in CFScript works fine, and even work across DSN's, much improved in 9.0.1! watch http://tv.adobe.com/watch/max-2010-develop/coldfusion-undocumented/
How do you setup development and live sites for ORM?
same as without ORM, but you may look into this.ormSettings.dbCreate if u mean the DB creation part
What about HQL?
What about it? :) Use it when u want an array of objects, but nothing stopping you from using the good old <cfquery>
When should we just do the SQL ourselves by hand?!
When you feel like HQL doesn't do what you want.
Check out: Things to watch out for in ColdFusion 9 with CF-ORM however keep in mind that some points are no longer true for 9.0.1
I've just started using Zend Framework and Doctrine as its ORM, and I have some doubts regarding the model. It's obvious that the purpose of the ORM is just to map my domain model to database model, but I'm curious how you would model various reports needed on a Web application?
From my point of view, and correct me if I'm wrong, I should avoid writing any queries in the controller (Doctrine Query Language queries, in this case). So, if I want some arbitrary report (e.g. revenue per department, split by month), should I have a special reporting "service" in the domain? This service would fetch my report from the database using ORM queries.
If you could shed some light on this topic, I'd be grateful.
For sure, sometimes DQL is insufficient. In Doctrine2 you can extend it. But Doctrine 1.x is not stupid and you can use native SQL with it: http://www.doctrine-project.org/projects/orm/1.2/docs/manual/native-sql/en
If ORM is insufficient, you can use native SQL. Reporting is the case where SQL queries become tooo complex for ANY simple QL you can image. So... I say go for native queries if you can't avoid it. But save Doctrine for everything else.
I can connect with the DataContext to the Oracle database however I get errors in running the query against the oracle database. I looked at the SQL generated and it is for MSSQL and not Oracle PSQL.
Does anybody know of a decent easy to use wrapper to use LINQ against an Oracle Database?
No, LINQ to SQL is very much MS SQL only - think of it as a client driver.
Microsoft is/was helping Oracle and DataDirect develop providers for Oracle and other non-MS database servers.
We use the OraDirect driver from Devart. It includes ADO.NET Entity framework support. You can download a trial version here. You may then use LINQ to entities or entity SQL on top of this.
The pricing of this is quite developer friendly, you pay per developer seat and you may use it however you like.
Another big advantage of this driver is that you can use it without installing an Oracle client, this is a big plus and worth the price alone.
#Greg: We evaluated the datadirect drivers as well, but the performance was poor and cost astronomical.
Edit: It seems DevArt announced a beta with LINQ support recently
One thing you might look into is that there is now LINQ to Entities, which leverages the MS Entity Framework, which I believe is DB agnostic. I'm still looking into how it works myself, but if you could create an ADO.NET Data Entity that interfaces with Oracle, you could then use LINQ against that Entity.
There's also Lightspeed which has a per-organization (not per-developer) license scheme and seems to have a pretty solid documentation library and a free trial version (up to 8 entities). I'm checking this out presently.
After a long search I found DbLinq and should do the trick. I am going to try it myself. I came across your question because I was searching for the same solution. Hope it helps.
Do look at Linq to entities though. I have a datareader populate a collection of objects that are mapped to the oracle table. I can use linq to query that collection in very powerful, simple, and easy ways. I love it. Highly recommend.
Try Devart LinqConnect. This product allows you to work with Oracle, etc.
Why not try ALinq ？ http://www.alinq.org
Look in codeplex:
Linq To Oracle project
Not an easy way, at least until a good provider is produced.
Really MS should provide at least an OLEDB Linq provider. After all, Linq to Sql is basically an implementation of IQueryable with designer support.
Another cross-database solution that works fairly well across Oracle, SQLite, MySQL and SQL Server is eXpress Persistent Objects