Search Results

Search found 39613 results on 1585 pages for 'large object heap'.

Page 1/1585 | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

• Know more about shared pool subpool

  - by Liu Maclean(???)

  ????T.askmaclean.com???Shared Pool?SubPool?????,????????_kghdsidx_count ? subpool ??subpool????( ???duration)???: SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi PL/SQL Release 10.2.0.5.0 - Production CORE    10.2.0.5.0      Production TNS for Linux: Version 10.2.0.5.0 - Production NLSRTL Version 10.2.0.5.0 - Production SQL> set linesize 200 pagesize 1400 SQL> show parameter kgh NAME                                 TYPE                             VALUE ------------------------------------ -------------------------------- ------------------------------ _kghdsidx_count                      integer                          7 SQL> oradebug setmypid; Statement processed. SQL> oradebug dump heapdump 536870914; Statement processed. SQL> oradebug tracefile_name /s01/admin/G10R25/udump/g10r25_ora_11783.trc [oracle@vrh8 dbs]$ grep "sga heap"  /s01/admin/G10R25/udump/g10r25_ora_11783.trc HEAP DUMP heap name="sga heap"  desc=0x60000058 HEAP DUMP heap name="sga heap(1,0)"  desc=0x60036110 FIVE LARGEST SUB HEAPS for heap name="sga heap(1,0)"   desc=0x60036110 HEAP DUMP heap name="sga heap(2,0)"  desc=0x6003f938 FIVE LARGEST SUB HEAPS for heap name="sga heap(2,0)"   desc=0x6003f938 HEAP DUMP heap name="sga heap(3,0)"  desc=0x60049160 FIVE LARGEST SUB HEAPS for heap name="sga heap(3,0)"   desc=0x60049160 HEAP DUMP heap name="sga heap(4,0)"  desc=0x60052988 FIVE LARGEST SUB HEAPS for heap name="sga heap(4,0)"   desc=0x60052988 HEAP DUMP heap name="sga heap(5,0)"  desc=0x6005c1b0 FIVE LARGEST SUB HEAPS for heap name="sga heap(5,0)"   desc=0x6005c1b0 HEAP DUMP heap name="sga heap(6,0)"  desc=0x600659d8 FIVE LARGEST SUB HEAPS for heap name="sga heap(6,0)"   desc=0x600659d8 HEAP DUMP heap name="sga heap(7,0)"  desc=0x6006f200 FIVE LARGEST SUB HEAPS for heap name="sga heap(7,0)"   desc=0x6006f200 SQL> alter system set "_kghdsidx_count"=6 scope=spfile; System altered. SQL> startup force; ORACLE instance started. Total System Global Area  859832320 bytes Fixed Size                  2100104 bytes Variable Size             746587256 bytes Database Buffers          104857600 bytes Redo Buffers                6287360 bytes Database mounted. Database opened. SQL> SQL> oradebug setmypid; Statement processed. SQL> oradebug dump heapdump 536870914; Statement processed. SQL> oradebug tracefile_name /s01/admin/G10R25/udump/g10r25_ora_11908.trc [oracle@vrh8 dbs]$ grep "sga heap"  /s01/admin/G10R25/udump/g10r25_ora_11908.trc HEAP DUMP heap name="sga heap"  desc=0x60000058 HEAP DUMP heap name="sga heap(1,0)"  desc=0x600360f0 FIVE LARGEST SUB HEAPS for heap name="sga heap(1,0)"   desc=0x600360f0 HEAP DUMP heap name="sga heap(2,0)"  desc=0x6003f918 FIVE LARGEST SUB HEAPS for heap name="sga heap(2,0)"   desc=0x6003f918 HEAP DUMP heap name="sga heap(3,0)"  desc=0x60049140 FIVE LARGEST SUB HEAPS for heap name="sga heap(3,0)"   desc=0x60049140 HEAP DUMP heap name="sga heap(4,0)"  desc=0x60052968 FIVE LARGEST SUB HEAPS for heap name="sga heap(4,0)"   desc=0x60052968 HEAP DUMP heap name="sga heap(5,0)"  desc=0x6005c190 FIVE LARGEST SUB HEAPS for heap name="sga heap(5,0)"   desc=0x6005c190 HEAP DUMP heap name="sga heap(6,0)"  desc=0x600659b8 FIVE LARGEST SUB HEAPS for heap name="sga heap(6,0)"   desc=0x600659b8 SQL> SQL> alter system set "_kghdsidx_count"=2 scope=spfile; System altered. SQL> SQL> startup force; ORACLE instance started. Total System Global Area  851443712 bytes Fixed Size                  2100040 bytes Variable Size             738198712 bytes Database Buffers          104857600 bytes Redo Buffers                6287360 bytes Database mounted. Database opened. SQL> oradebug setmypid; Statement processed. SQL> oradebug dump heapdump 2; Statement processed. SQL> oradebug tracefile_name /s01/admin/G10R25/udump/g10r25_ora_12003.trc [oracle@vrh8 ~]$ grep "sga heap"  /s01/admin/G10R25/udump/g10r25_ora_12003.trc HEAP DUMP heap name="sga heap"  desc=0x60000058 HEAP DUMP heap name="sga heap(1,0)"  desc=0x600360b0 HEAP DUMP heap name="sga heap(2,0)"  desc=0x6003f8d SQL> alter system set cpu_count=16 scope=spfile; System altered. SQL> startup force; ORACLE instance started. Total System Global Area  851443712 bytes Fixed Size                  2100040 bytes Variable Size             738198712 bytes Database Buffers          104857600 bytes Redo Buffers                6287360 bytes Database mounted. Database opened. SQL> oradebug setmypid; Statement processed. SQL>  oradebug dump heapdump 2; Statement processed. SQL> oradebug tracefile_name /s01/admin/G10R25/udump/g10r25_ora_12065.trc [oracle@vrh8 ~]$ grep "sga heap"  /s01/admin/G10R25/udump/g10r25_ora_12065.trc HEAP DUMP heap name="sga heap"  desc=0x60000058 HEAP DUMP heap name="sga heap(1,0)"  desc=0x600360b0 HEAP DUMP heap name="sga heap(2,0)"  desc=0x6003f8d8 SQL> show parameter sga_target NAME                                 TYPE                             VALUE ------------------------------------ -------------------------------- ------------------------------ sga_target                           big integer                      0 SQL> alter system set sga_target=1000M scope=spfile; System altered. SQL> startup force; ORACLE instance started. Total System Global Area 1048576000 bytes Fixed Size                  2101544 bytes Variable Size             738201304 bytes Database Buffers          301989888 bytes Redo Buffers                6283264 bytes Database mounted. Database opened. SQL> alter system set sga_target=1000M scope=spfile; System altered. SQL> startup force; ORACLE instance started. Total System Global Area 1048576000 bytes Fixed Size                  2101544 bytes Variable Size             738201304 bytes Database Buffers          301989888 bytes Redo Buffers                6283264 bytes Database mounted. Database opened. SQL> SQL> SQL> oradebug setmypid; Statement processed. SQL> oradebug dump heapdump 2; Statement processed. SQL>  oradebug tracefile_name /s01/admin/G10R25/udump/g10r25_ora_12148.trc SQL> SQL> Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options [oracle@vrh8 dbs]$ grep "sga heap"  /s01/admin/G10R25/udump/g10r25_ora_12148.trc HEAP DUMP heap name="sga heap"  desc=0x60000058 HEAP DUMP heap name="sga heap(1,0)"  desc=0x60036690 HEAP DUMP heap name="sga heap(1,1)"  desc=0x60037ee8 HEAP DUMP heap name="sga heap(1,2)"  desc=0x60039740 HEAP DUMP heap name="sga heap(1,3)"  desc=0x6003af98 HEAP DUMP heap name="sga heap(2,0)"  desc=0x6003feb8 HEAP DUMP heap name="sga heap(2,1)"  desc=0x60041710 HEAP DUMP heap name="sga heap(2,2)"  desc=0x60042f68 _enable_shared_pool_durations:?????????10g????shared pool duration??,?????sga_target?0?????false; ???10.2.0.5??cursor_space_for_time???true??????false,???10.2.0.5??cursor_space_for_time????? SQL> alter system set "_enable_shared_pool_durations"=false scope=spfile; System altered. SQL> SQL> startup force; ORACLE instance started. Total System Global Area 1048576000 bytes Fixed Size                  2101544 bytes Variable Size             738201304 bytes Database Buffers          301989888 bytes Redo Buffers                6283264 bytes Database mounted. Database opened. SQL> oradebug setmypid; Statement processed. SQL> oradebug dump heapdump 2; Statement processed. SQL> oradebug tracefile_name /s01/admin/G10R25/udump/g10r25_ora_12233.trc SQL> SQL> Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options\ [oracle@vrh8 dbs]$ grep "sga heap"   /s01/admin/G10R25/udump/g10r25_ora_12233.trc HEAP DUMP heap name="sga heap"  desc=0x60000058 HEAP DUMP heap name="sga heap(1,0)"  desc=0x60036690 HEAP DUMP heap name="sga heap(2,0)"  desc=0x6003feb8 ??:1._kghdsidx_count ??? shared pool subpool???, _kghdsidx_count???????7 ??? 7? shared pool subpool 2.??????? subpool???4? sub partition ?: sga heap(1,0) sga heap(1,1) sga heap(1,2) sga heap(1,3) ????? cpu??? ?????_kghdsidx_count, ???? ?10g ?AUTO SGA ??? shared pool duration???, duration ??4?: Session duration Instance duration (never freed) Execution duration (freed fastest) Free memory ??? shared pool duration???? ?10gR1?Shared Pool?shrink??????????,?????????????Buffer Cache???????????granule,????Buffer Cache?granule????granule header?Metadata(???buffer header??RAC??Lock Elements)????,?????????????????????shared pool????????duration(?????)?chunk??????granule?,????????????granule??10gR2????Buffer Cache Granule????????granule header?buffer?Metadata(buffer header?LE)????,??shared pool???duration?chunk????????granule,??????buffer cache?shared pool??????????????10gr2?streams pool?????????(???????streams pool duration????) reference : http://www.oracledatabase12g.com/archives/understanding-automatic-sga-memory-management.html

  Read the article

• Architecture Best Practice (MVC): Repository Returns Object & Object Member Accessed Directly or Repository Returns Object Member

  - by coderabbi

  Architecturally speaking, which is the preferable approach (and why)? $validation_date = $users_repository->getUser($user_id)->validation_date; Seems to violate Law of Demeter by accessing member of object returned by method call Seems to violate Encapsulation by accessing object member directly $validation_date = $users_repository->getUserValidationDate($user_id); Seems to violate Single Responsibility Principle as $users_repository no longer just returns User objects

  Read the article

• Java heap space

  - by java_mouse

  In Java/JVM, why do we call the memory place where Java creates objects as "Heap"? Does it use the Heap Data Structure to create/remove/maintain the objects? As I read in the documentation of Heap data structure, the algorithm compares the objects with existing nodes and places them in such a way that Parent object is "greater" than the children. ( Or "lesser" in case of min heap). So in JVM, how are the objects compared against each other before placing them in the heap?

  Read the article

• When would you want two references to the same object?

  - by HCBPshenanigans

  In Java specifically, but likely in other languages as well; When would it be useful to have two references to the same object? Example: Dog a = new Dog(); Dob b = a; Is there a situation where this would be useful? Why would this be a preferred solution to using a whenever you want to interact with the object represented by a? Edit: Can I just say that all of your dog related examples are Delightful!

  Read the article

• How to safely copy an object?

  - by Prog

  This question is going to be a little long. Please bear with me. Something that happened in a project of mine made me think about how to safely copy objects. I'll present the situation I had and then ask a question. There was a class SomeClass: class SomeClass{ Thing[] things; public SomeClass(Thing[] things){ this.things = things; } // irrelevant stuff omitted public SomeClass copy(){ return new SomeClass(things); } } There was another class Processor that takes SomeClass objects, copies them (via someClassInstance.copy()), manipulates the copy's state, and returns the copy. Here it is: class Processor{ public SomeClass processObject(SomeClass object){ SomeClass copy = object.copy(); manipulateTheCopy(copy); return copy; } // irrelevant stuff omitted } I ran this, and it had bugs. I looked into these bugs, and it turned out that the manipulations Processor does on copy actually affect not only the copy, but also the original SomeClass object that was passed into processObject. I found out that it was because the original and the copy shared state - because the original passed it's field things into the copy when creating it. This made me realize that copying objects is harder than simply instantiating them with the same fields as the original. For the two objects to be completely disconnected, without any shared state, each of the fields passed to the copy also has to be copied. And if that object contains other objects - they have to be copied too. And so on. So basically, in order to be able to actually copy an object, each class in the system must have a copy() method, that also invokes copy() on all of it's fields, and so on. So for example, for copy() in SomeClass to work, it needs to look like this: public SomeClass copy(){ Thing[] copyThings = new Thing[things.length]; for(int i=0; i<things.length; i++) copyThings[i] = things[i].copy(); return new SomeClass(copyThings); } And if Thing has object fields of it's own, than it's own copy() method must be appropriate: class Thing{ Apple apple; Pencil pencil; int number; public Thing(Apple apple, Pencil pencil, int number){ this.apple = apple; this.pencil = pencil; this.number = number; } public Thing copy(){ // 'number' is a primitve. return new Thing(apple.getCopy(), pencil.getCopy(), number); } } And so on. Of course, instead of all classes having a copy() method, the copying mechanism can happen in all of the getters and the constructors of classes (unless places where it isn't suitable, for example when the field points to an external object, not to an object that 'is part' of this object). Still, that means that in order to be able to safely copy an object - most classes would have to have copying mechanisms in their getters. My question is divided into two parts: How frequently do you need to get a copy of an object? Is this a regular issue? Is the technique described common and/or reasonable? Or is there a better way to make safe copies of objects? Or is there an easier way to safely copy objects, without them sharing any state?

  Read the article

• Should an object know its own ID?

  - by xenoterracide

  obj.id seems fairly common and also seems to fall within the range of something an object could know about itself. I find myself asking why should my object know its own id? It doesn't seem to have a reason to have it? One of the main reason for it existing is retrieve it, and so my repositories need to know it, and thus use it for database interaction. I also once encountered a problem where I wanted to serialize an object to JSON for a RESTful API where the id did not seem to fit in the payload, but only the URI and including it in the object made that more difficult. Should an object know it's own id? why or why not?

  Read the article

• Object oriented design importance

  - by user5507

  I started studying Object Oriented Design and Modelling using the this book by James Rumbaugh. It uses a tool called Object Modeling Technique (OMT). I have certain newbie questions. I searched the net, but couldn't get answers The book is pretty old. Don't know why the school told me to learn this. I know OMT is a predecessor of the Unified Modeling Language (UML). So its a waste? Whether the concepts change very much when we move from OMT to UML? I know OMT has Object, Dynamic and Functional Model. Wikipedia says UML is compatible with OMT and UML is a model too. As per wikipedia the UML models are Static and Dynamic and they are represented by different diagrams like class, object, activity, sequence..... I couldn't find the equivalence of this in OMT. I read that there are many object oriented development methods like OMT, Booch,.... Which one is used by Industry ? Where could I get a comparison of different Object oriented development methods?

  Read the article

• JVM process resident set size "equals" max heap size, not current heap size

  - by Volune

  After a few reading about jvm memory (here, here, here, others I forgot...), I am expecting the resident set size of my java process to be roughly equal to the current heap space capacity. That's not what the numbers are saying, it seems to be roughly equal to the max heap space capacity: Resident set size: # echo 0 $(cat /proc/1/smaps | grep Rss | awk '{print $2}' | sed 's#^#+#') | bc 11507912 # ps -C java -O rss | gawk '{ count ++; sum += $2 }; END {count --; print "Number of processes =",count; print "Memory usage per process =",sum/1024/count, "MB"; print "Total memory usage =", sum/1024, "MB" ;};' Number of processes = 1 Memory usage per process = 11237.8 MB Total memory usage = 11237.8 MB Java heap # jmap -heap 1 Attaching to process ID 1, please wait... Debugger attached successfully. Server compiler detected. JVM version is 24.55-b03 using thread-local object allocation. Garbage-First (G1) GC with 18 thread(s) Heap Configuration: MinHeapFreeRatio = 10 MaxHeapFreeRatio = 20 MaxHeapSize = 10737418240 (10240.0MB) NewSize = 1363144 (1.2999954223632812MB) MaxNewSize = 17592186044415 MB OldSize = 5452592 (5.1999969482421875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 20971520 (20.0MB) MaxPermSize = 85983232 (82.0MB) G1HeapRegionSize = 2097152 (2.0MB) Heap Usage: G1 Heap: regions = 2560 capacity = 5368709120 (5120.0MB) used = 1672045416 (1594.586769104004MB) free = 3696663704 (3525.413230895996MB) 31.144272834062576% used G1 Young Generation: Eden Space: regions = 627 capacity = 3279945728 (3128.0MB) used = 1314914304 (1254.0MB) free = 1965031424 (1874.0MB) 40.089514066496164% used Survivor Space: regions = 49 capacity = 102760448 (98.0MB) used = 102760448 (98.0MB) free = 0 (0.0MB) 100.0% used G1 Old Generation: regions = 147 capacity = 1986002944 (1894.0MB) used = 252273512 (240.5867691040039MB) free = 1733729432 (1653.413230895996MB) 12.702574926293766% used Perm Generation: capacity = 39845888 (38.0MB) used = 38884120 (37.082786560058594MB) free = 961768 (0.9172134399414062MB) 97.58628042120682% used 14654 interned Strings occupying 2188928 bytes. Are my expectations wrong? What should I expect? I need the heap space to be able to grow during spikes (to avoid very slow Full GC), but I would like to have the resident set size as low as possible the rest of the time, to benefit the other processes running on the server. Is there a better way to achieve that? Linux 3.13.0-32-generic x86_64 java version "1.7.0_55" Running in Docker version 1.1.2 Java is running elasticsearch 1.2.0: /usr/bin/java -Xms5g -Xmx10g -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20 -Xss256k -Djava.awt.headless=true -XX:+UseG1GC -XX:MaxGCPauseMillis=350 -XX:InitiatingHeapOccupancyPercent=45 -XX:+AggressiveOpts -XX:+UseCompressedOops -XX:-OmitStackTraceInFastThrow -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintClassHistogram -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCApplicationConcurrentTime -Xloggc:/opt/elasticsearch/logs/gc.log -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/opt elasticsearch/logs/heapdump.hprof -XX:ErrorFile=/opt/elasticsearch/logs/hs_err.log -Des.logger.port=99999 -Des.logger.host=999.999.999.999 -Delasticsearch -Des.foreground=yes -Des.path.home=/opt/elasticsearch -cp :/opt/elasticsearch/lib/elasticsearch-1.2.0.jar:/opt/elasticsearch/lib/*:/opt/elasticsearch/lib/sigar/* org.elasticsearch.bootstrap.Elasticsearch There actually are 5 elasticsearch nodes, each in a different docker container. All have about the same memory usage. Some stats about the index: size: 9.71Gi (19.4Gi) docs: 3,925,398 (4,052,694)

  Read the article

• SQL Table stored as a Heap - the dangers within

  - by MikeD

  Nearly all of the time I create a table, I include a primary key, and often that PK is implemented as a clustered index. Those two don't always have to go together, but in my world they almost always do. On a recent project, I was working on a data warehouse and a set of SSIS packages to import data from an OLTP database into my data warehouse. The data I was importing from the business database into the warehouse was mostly new rows, sometimes updates to existing rows, and sometimes deletes. I decided to use the MERGE statement to implement the insert, update or delete in the data warehouse, I found it quite performant to have a stored procedure that extracted all the new, updated, and deleted rows from the source database and dump it into a working table in my data warehouse, then run a stored proc in the warehouse that was the MERGE statement that took the rows from the working table and updated the real fact table. Use Warehouse CREATE TABLE Integration.MergePolicy (PolicyId int, PolicyTypeKey int, Premium money, Deductible money, EffectiveDate date, Operation varchar(5)) CREATE TABLE fact.Policy (PolicyKey int identity primary key, PolicyId int, PolicyTypeKey int, Premium money, Deductible money, EffectiveDate date) CREATE PROC Integration.MergePolicy as begin begin tran Merge fact.Policy as tgtUsing Integration.MergePolicy as SrcOn (tgt.PolicyId = Src.PolicyId) When not matched by Target then Insert (PolicyId, PolicyTypeKey, Premium, Deductible, EffectiveDate)values (src.PolicyId, src.PolicyTypeKey, src.Premium, src.Deductible, src.EffectiveDate) When matched and src.Operation = 'U' then Update set PolicyTypeKey = src.PolicyTypeKey,Premium = src.Premium,Deductible = src.Deductible,EffectiveDate = src.EffectiveDate When matched and src.Operation = 'D' then Delete ;delete from Integration.WorkPolicy commit end Notice that my worktable (Integration.MergePolicy) doesn't have any primary key or clustered index. I didn't think this would be a problem, since it was relatively small table and was empty after each time I ran the stored proc. For one of the work tables, during the initial loads of the warehouse, it was getting about 1.5 million rows inserted, processed, then deleted. Also, because of a bug in the extraction process, the same 1.5 million rows (plus a few hundred more each time) was getting inserted, processed, and deleted. This was being sone on a fairly hefty server that was otherwise unused, and no one was paying any attention to the time it was taking. This week I received a backup of this database and loaded it on my laptop to troubleshoot the problem, and of course it took a good ten minutes or more to run the process. However, what seemed strange to me was that after I fixed the problem and happened to run the merge sproc when the work table was completely empty, it still took almost ten minutes to complete. I immediately looked back at the MERGE statement to see if I had some sort of outer join that meant it would be scanning the target table (which had about 2 million rows in it), then turned on the execution plan output to see what was happening under the hood. Running the stored procedure again took a long time, and the plan output didn't show me much - 55% on the MERGE statement, and 45% on the DELETE statement, and table scans on the work table in both places. I was surprised at the relative cost of the DELETE statement, because there were really 0 rows to delete, but I was expecting to see the table scans. (I was beginning now to suspect that my problem was because the work table was being stored as a heap.) Then I turned on STATS_IO and ran the sproc again. The output was quite interesting.Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.Table 'Policy'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.Table 'MergePolicy'. Scan count 1, logical reads 433276, physical reads 60, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. I've reproduced the above from memory, the details aren't exact, but the essential bit was the very high number of logical reads on the table stored as a heap. Even just doing a SELECT Count(*) from Integration.MergePolicy incurred that sort of output, even though the result was always 0. I suppose I should research more on the allocation and deallocation of pages to tables stored as a heap, but I haven't, and my original assumption that a table stored as a heap with no rows would only need to read one page to answer any query was definitely proven wrong. It's likely that some sort of physical defragmentation of the table may have cleaned that up, but it seemed that the easiest answer was to put a clustered index on the table. After doing so, the execution plan showed a cluster index scan, and the IO stats showed only a single page read. (I aborted my first attempt at adding a clustered index on the table because it was taking too long - instead I ran TRUNCATE TABLE Integration.MergePolicy first and added the clustered index, both of which took very little time). I suspect I may not have noticed this if I had used TRUNCATE TABLE Integration.MergePolicy instead of DELETE FROM Integration.MergePolicy, since I'm guessing that the truncate operation does some rather quick releasing of pages allocated to the heap table. In the future, I will likely be much more careful to have a clustered index on every table I use, even the working tables. Mike  

  Read the article

• find second smallest element in Fibonacci Heap

  - by Longeyes

  I need to describe an algorithm that finds the second smallest element in a Fibonacci-Heap using the Operations: Insert, ExtractMin, DecreaseKey and GetMin. The last one is an algorithm previously implemented to find and return the smallest element of the heap. I thought I'd start by extracting the minimum, which results in its children becoming roots. I could then use GetMin to find the second smallest element. But it seems to me that I'm overlooking other cases because I don't know when to use Insert and DecreaseKey, and the way the question is phrased seems to suggest I should need them.

  Read the article

• Why are two different concepts both called "heap"?

  - by Andrey Fedorov

  Why are the runtime heap used for dynamic memory allocation in C-style languages and the data structure both called "the heap"? Is there some relation?

  Read the article

• Taking Object Oriented development to the next level

  - by Songo

  Can you mention some advanced OO topics or concepts that one should be aware of? I have been a developer for 2 years now and currently aiming for a certain company that requires a web developer with a minimum experience of 3 years. I imagine the interview will have the basic object oriented topics like (Abstraction, Polymorphism, Inheritance, Design patterns, UML, Databases and ORMs, SOLID principles, DRY principle, ...etc) I have these topics covered, but what I'm looking forward to is bringing up topics such as Efferent Coupling, Afferent Coupling, Instability, The law of Demeter, ...etc. Till few days ago I never knew such concepts existed (maybe because I'm a communication engineer basically not a CS graduate.) Can you please recommend some more advanced topics concerning object oriented programming?

  Read the article

• How to use the client object model with SharePoint2010

  - by ybbest

  In SharePoint2010, you can use client object model to communicate with SharePoint server. Today, I’d like to show you how to achieve this by using the c# console application. You can download the solution here. 1. Create a Console application in visual studio and add the following references to the project. 2. Insert your code as below ClientContext context = new ClientContext("http://demo2010a"); Web currentWeb = context.Web; context.Load(currentWeb, web =&gt; web.Title); context.ExecuteQuery(); Console.WriteLine(currentWeb.Title); Console.ReadLine(); 3. Run your code then you will get the web title displayed as shown below Note: If you got the following errors, you need to change your target framework from .Net Framework 4 client profile to .Net Framework 4 as shown below: Change from TO

  Read the article

• Object behaviour or separate class?

  - by Andrew Stephens

  When it comes to OO database access you see two common approaches - the first is to provide a class (say "Customer") with methods such as Retrieve(), Update(), Delete(), etc. The other is to keep the Customer class fairly lightweight (essentially just properties) and perform the database access elsewhere, e.g. using a repository. This choice of approaches doesn't just apply to database access, it can crop up in many different OOD scenarios. So I was wondering if one way is preferable over the other (although I suspect the answer will be "it depends")! Another dev on our team argues that to be truly OO the class should be "self-contained", i.e. providing all the methods necessary to manipulate and interact with that object. I personally prefer the repository approach - I don't like bloating the Customer class with all that functionality, and I feel it results in cleaner code having it elsewhere, but I can't help thinking I'm seriously violating core OO concepts! And what about memory implications? If I retrieve thousands of Customer objects I'm assuming those with the data access methods will take up a lot more memory than the property-only objects?

  Read the article

• Is the heap actually a heap?

  - by ElectricDialect

  In .NET (and Java as far as I know), the area where objects are dynamically allocated is referred to as the managed heap. However, most documentation that describes how the managed heap works depicts it as a linear data structure, such as a linked list or stack. So, is the managed heap actually a heap, or is it implemented with some other data structure? If it actually does not use a heap data structure, is seems like a significant failure of terminology to overload the meaning of this word. If it is in fact a heap data structure, what is the value that satisfies the heap property: the size of the allocated memory region?

  Read the article

• Detect application heap size in Android

  - by hgpc

  How do you detect the application heap size available to an Android app? I heard there's a function that does this in later versions of the SDK. In any case, I'm looking for solution that works for 1.5 and upwards.

  Read the article

• Any enlightenment for understanding Object Oriented Programming? [closed]

  - by ????

  I studied computer science near the end of 1980s, and wasn't taught OOP that formally. With Pascal or C, when I understand the top-down design of functions, and the idea of black box, then everything just seem to make sense, as if there is a "oh I get it!" -- some kind of totally getting it and enlightenment feeling. But with OOP, all I know was the mechanics: the class, instance, method, inheritance, polymorphism, encapsulation. It was like, I knew all the "this is how it is", but never had the feeling of "I totally get it", the enlightened feeling. Would somebody be able to describe it, or point to a chapter in some book or paper which talks about OOP so that the reader can feel: "I totally get it!" on OOP?

  Read the article

• (1 2 3 . #<void>)- heapsort

  - by superguay

  Hello everybody: I tried to implement a "pairing heap" with all the regular operations (merge, delete-min etc.), then I've been requested to write a function that would sort a list using my newly constructed heap implementation. Unfortunately it seems that someting goes wrong... Here's the relevant code: (define (heap-merge h1 h2) (cond ((heap-empty? h1) h2) ((heap-empty? h2) h1) (else (let ((min1 (heap-get-min h1)) (min2 (heap-get-min h2))) (if ((heap-get-less h1) min1 min2) (make-pairing-heap (heap-get-less h1) min1 (cons h2 (heap-get-subheaps h1))) (make-pairing-heap (heap-get-less h1) min2 (cons h1 (heap-get-subheaps h2)))))))) (define (heap-insert element h) (heap-merge (make-pairing-heap (heap-get-less h) element '()) h)) (define (heap-delete-min h) (define (merge-in-pairs less? subheaps) (cond ((null? subheaps) (make-heap less?)) ((null? (cdr subheaps)) (car subheaps)) (else (heap-merge (heap-merge (car subheaps) (cadr subheaps)) (merge-in-pairs less? (cddr subheaps)))))) (if (heap-empty? h) (error "expected pairing-heap for first argument, got an empty heap ") (merge-in-pairs (heap-get-less h) (heap-get-subheaps h)))) (define (heapsort l less?) (let aux ((h (accumulate heap-insert (make-heap less?) l))) (if (not (heap-empty? h)) (cons (heap-get-min h) (aux (heap-delete-min h)))))) And these are some selectors that may help you to understand the code: (define (make-pairing-heap less? min subheaps) (cons less? (cons min subheaps))) (define (make-heap less?) (cons less? '())) (define (heap-get-less h) (car h)) (define (heap-empty? h) (if (null? (cdr h)) #t #f)) Now lets get to the problem: When i run 'heapsort' it returns the sorted list with "void", as you can see: (heapsort (list 1 2 3) <) (1 2 3 . #)..HOW CAN I FIX IT? Regards, Superguay

  Read the article

• Generic object to object mapping with parametrized constructor

  - by Rody van Sambeek

  I have a data access layer which returns an IDataRecord. I have a WCF service that serves DataContracts (dto's). These DataContracts are initiated by a parametrized constructor containing the IDataRecord as follows: [DataContract] public class DataContractItem { [DataMember] public int ID; [DataMember] public string Title; public DataContractItem(IDataRecord record) { this.ID = Convert.ToInt32(record["ID"]); this.Title = record["title"].ToString(); } } Unfortanately I can't change the DAL, so I'm obliged to work with the IDataRecord as input. But in generat this works very well. The mappings are pretty simple most of the time, sometimes they are a bit more complex, but no rocket science. However, now I'd like to be able to use generics to instantiate the different DataContracts to simplify the WCF service methods. I want to be able to do something like: public T DoSomething<T>(IDataRecord record) { ... return new T(record); } So I'd tried to following solutions: Use a generic typed interface with a constructor. doesn't work: ofcourse we can't define a constructor in an interface Use a static method to instantiate the DataContract and create a typed interface containing this static method. doesn't work: ofcourse we can't define a static method in an interface Use a generic typed interface containing the new() constraint doesn't work: new() constraint cannot contain a parameter (the IDataRecord) Using a factory object to perform the mapping based on the DataContract Type. does work, but: not very clean, because I now have a switch statement with all mappings in one file. I can't find a real clean solution for this. Can somebody shed a light on this for me? The project is too small for any complex mapping techniques and too large for a "switch-based" factory implementation.

  Read the article

• How can a 1Gb Java heap on a 64bit machine use 3Gb of VIRT space?

  - by Graeme Moss

  I run the same process on a 32bit machine as on a 64bit machine with the same memory VM settings (-Xms1024m -Xmx1024m) and similar VM version (1.6.0_05 vs 1.6.0_16). However the virtual space used by the 64bit machine (as shown in top under "VIRT") is almost three times as big as that in 32bit! I know 64bit VMs will use a little more memory for the larger references, but how can it be three times as big? Am I reading VIRT in top incorrectly? Full data shown below, showing top and then the result of jmap -heap, first for 64bit, then for 32bit. Note the VIRT for 64bit is 3319m for 32bit is 1220m. * 64bit * PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 22534 agent 20 0 3319m 163m 14m S 4.7 2.0 0:04.28 java $ jmap -heap 22534 Attaching to process ID 22534, please wait... Debugger attached successfully. Server compiler detected. JVM version is 10.0-b19 using thread-local object allocation. Parallel GC with 4 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 1073741824 (1024.0MB) NewSize = 2686976 (2.5625MB) MaxNewSize = -65536 (-0.0625MB) OldSize = 5439488 (5.1875MB) NewRatio = 2 SurvivorRatio = 8 PermSize = 21757952 (20.75MB) MaxPermSize = 88080384 (84.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 268500992 (256.0625MB) used = 247066968 (235.62142181396484MB) free = 21434024 (20.441078186035156MB) 92.01715277089181% used From Space: capacity = 44695552 (42.625MB) used = 0 (0.0MB) free = 44695552 (42.625MB) 0.0% used To Space: capacity = 44695552 (42.625MB) used = 0 (0.0MB) free = 44695552 (42.625MB) 0.0% used PS Old Generation capacity = 715849728 (682.6875MB) used = 0 (0.0MB) free = 715849728 (682.6875MB) 0.0% used PS Perm Generation capacity = 21757952 (20.75MB) used = 16153928 (15.405586242675781MB) free = 5604024 (5.344413757324219MB) 74.24378912132907% used * 32bit * PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 30168 agent 20 0 1220m 175m 12m S 0.0 2.2 0:13.43 java $ jmap -heap 30168 Attaching to process ID 30168, please wait... Debugger attached successfully. Server compiler detected. JVM version is 14.2-b01 using thread-local object allocation. Parallel GC with 8 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 1073741824 (1024.0MB) NewSize = 1048576 (1.0MB) MaxNewSize = 4294901760 (4095.9375MB) OldSize = 4194304 (4.0MB) NewRatio = 8 SurvivorRatio = 8 PermSize = 16777216 (16.0MB) MaxPermSize = 67108864 (64.0MB) Heap Usage: PS Young Generation Eden Space: capacity = 89522176 (85.375MB) used = 80626352 (76.89128112792969MB) free = 8895824 (8.483718872070312MB) 90.0629940005033% used From Space: capacity = 14876672 (14.1875MB) used = 14876216 (14.187065124511719MB) free = 456 (4.3487548828125E-4MB) 99.99693479832048% used To Space: capacity = 14876672 (14.1875MB) used = 0 (0.0MB) free = 14876672 (14.1875MB) 0.0% used PS Old Generation capacity = 954466304 (910.25MB) used = 10598496 (10.107513427734375MB) free = 943867808 (900.1424865722656MB) 1.1104107034039412% used PS Perm Generation capacity = 16777216 (16.0MB) used = 11366448 (10.839889526367188MB) free = 5410768 (5.1601104736328125MB) 67.74930953979492% used

  Read the article

• operator "new" returning a non-local heap pointer for only one class ?

  - by KaluSingh Gabbar

  Language : C++ Platform : Windows Server 2003 I have an exe calling a DLL, in which when I allocate (new) the memory for class A (which is in DLL) it returns me a non-local heap pointer. I try to new other classes which are in DLL and "new" returns a valid heap pointer for them, its only Class A which is not being allocated properly. I am on windows and validating the heap by this function call : _CrtIsValidHeapPointer ( (const void *) pPtr ) I am seriously confused why this only happens with new-ing Class A and no other class ? (All Native Code)

  Read the article

• Can a loosely typed language be considered true object oriented?

  - by user61852

  Can a loosely typed programming language like PHP be really considered object oriented? I mean, the methods don't have returning types and method parameters has no declared type either. Doesn't class design require methods to have a return type? Don't methods signatures have specifically-typed parameters? How can OOP techniques help you code in PHP if you always have to check the types of parameters received because the language doesn't enforce types? Please, if I'm wrong, explain it to me. When you design things using UML, then code classes in PHP with no return-typed methods and no-type parameters... Is the code really compliant with the UML design? You spend time designing the architecture of your software, then the compiler doesn't force the programmer to follow your design while coding, letting he/she assign any object variable to any other variable with no "type-mismatch" warning.

  Read the article

• C++ min heap with user-defined type.

  - by bsg

  Hi, I am trying to implement a min heap in c++ for a struct type that I created. I created a vector of the type, but it crashed when I used make_heap on it, which is understandable because it doesn't know how to compare the items in the heap. How do I create a min-heap (that is, the top element is always the smallest one in the heap) for a struct type? The struct is below: struct DOC{ int docid; double rank; }; I want to compare the DOC structures using the rank member. How would I do this? I tried using a priority queue with a comparator class, but that also crashed, and it also seems silly to use a data structure which uses a heap as its underlying basis when what I really need is a heap anyway. Thank you very much, bsg

  Read the article

• Good practices for large scale development/delivery of software

  - by centic

  What practices do you apply when working with large teams on multiple versions of a software or multiple competing projects? What are best practices that can be used to still get the right things done first? Is there information available how big IT companies do development and management of some of their large projects, e.g. things like Oracle Database, WebSphere Application Server, Microsoft Windows, ....?

  Read the article

• A balanced binary search tree which is also a heap

  - by saeedn

  I'm looking for a data structure where each element in it has two keys. With one of them the structure is a BST and looking at the other one, data structure is a heap. With a little search, I found a structure called Treap. It uses the heap property with a random distribution on heap keys to make the BST balanced! What I want is a Balanced BST, which can be also a heap. The BST in Treap could be unbalanced if I insert elements with heap Key in the order of my choice. Is there such a data structure?

  Read the article

1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >