How to know if using an ORM will not lead to poor performance? -


i plan create small online dd3 game manager:

  • download client , play peer peer friends
  • online
  • or create characters sheet home game.

there (very) basics grid , 2d "graphics". used grid map , characters sheets persistence . also, not want spend time on it.

i'm experienced programmer. i'm used db tuning, , stored procedures. tasks highly time consuming. plan use , orm.

however, i've seens many industrial project performing poorly because of those. of time difference outrageous. here re points:

  1. how decide ( precise guideline/methods ) if orm kill preformance of apps? parameters important ( size? number of tables? number of queries?... )
  2. is orm fine tuning not more time consuming @ end odl school db tuning?

please precise in answers. i'll take time read each of them , check facts , examples.

orm perform worse (will less optimized) correctly designed database. gain in easier/quicker development if don't sql , plan move sql engine. suggest not use orm if not planning in moving 1 sql engine another. use if hate sql.

how decide:

  1. you hate sql: +1 orm.
  2. you love objects: +1 orm.
  3. your don't want use non-sql solution: +1 orm.
  4. you won't need stats or tables merging of many entities (tables/objects): +1 orm.
  5. you plan move dbms in future: +1 orm (or @ least sql framework).

you see it's not problem of how many queries run in application, it's problem of merging tables efficiently (and running in-efficient queries many times). merging 2 tables can less efficient in orm (for example orm might use 3 tables when need 1 , id relation table). , yes - fine tuning orm compared sql horror (you end writing in semi-sql , not give same level of control).


Comments

Post a Comment

Popular posts from this blog

php - Why I am getting the Error "Commands out of sync; you can't run this command now" -

the documentation of error mentioned in title says if commands out of sync; can't run command now in client code, calling client functions in wrong order. this can happen, example, if using mysql_use_result() , try execute new query before have called mysql_free_result(). can happen if try execute 2 queries return data without calling mysql_use_result() or mysql_store_result() in between. from here: http://dev.mysql.com/doc/refman/5.0/en/commands-out-of-sync.html but in first query not fetching data mysql database, inserting. , in second query getting data database. here code $connection = mysqli_connect("localhost","username","password","tbl_msgs"); if(mysqli_connect_errno($connection)) { die("failed connect mysql: " . mysqli_connect_error()); } $query = "insert users (total_comments, total_views) values ({$total_comments}, {$total_views});"; $query .= "insert msgs (no...
Read more

linux - Does gcc have any options to add version info in ELF binary file? -

i mean whether gcc can insert source code version infor elf binary section or similar. not want change source file, add info gcc option in makefile. you can emit version info text file, turn text file object file statically link executable. the first step simple have write code: script or write version info in format plain text file. write makefile rule produce version.o version.txt, using objcopy . you'll have object file 2 useful symbols defined in it: beginning , end of textual version info. add generated object executable, , you'll able access version 2 ways: running strings on binary, or writing code in application print version string (you'll need declare start , end symbols variables in header file).
Read more

java - Are there any classes that implement javax.persistence.Parameter<T>? -

i'm using named queries fetch entities database using jpa , hibernate , came across puzzling me: how come there no default implementations of javax.persistence.parameter interface? i rather impressed how @staticmetamodel used criteriabuilder in jpa2 meaning type safety , don't have mess around setting string names. wanted apply similar of jpa1 ejb's i'm working on: dealergroup_.class: public dealergroup_ { public parameter<integer> id = new parameterimpl<integer>("id"); /// etc... } dealergroupfacade.class: // ... public dealergroup fetch(integer id) { typedquery<dealergroup> query = em.createnamedquery("dealergroup.fetchbyid", dealergroup.class); query.setparameter(dealergroup_.id, query); return query.getsingleresult(); } // ... i surprised find there no implementations of parameter interface - of course, implement myself absence makes me suspicious may mistake using in way? should implementing parameter...
Read more