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Questions tagged [fragmentation]

An unefficient usage of disk storage in memory or hard drive.

189 questions
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Avoiding OutOfMemoryException during large, fast and frequent memory allocations in C#

Our application continuously allocates arrays for large quantities of data (say tens to hundreds of megabytes) which live for a shortish amount of time before being discarded. Done naively this can cause large object heap fragmentation, eventually…
James Thurley
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How to find out fragmented indexes and defragment them in PostgreSQL?

I've found how we can solve this problem in SQL Server here - but how can i do it in PostgreSQL?
Roman Martyshchuk
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How to see fragmentation of a specific file?

Is there a tool that would show me for a specific file on disk, how fragmented it is? (How many seeks does physical disk need to make if I were to read that file in a linear fashion)
Ghostrider
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7 answers

What is the golden rule for when to split code up into functions?

It's good to split code up into functions and classes for modularity / decoupling, but if you do it too much, you get really fragmented code which is also not good. What is the golden rule for when to split code up into functions?
Chetan
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Should I call GC.Collect immediately after using the large object heap to prevent fragmentation

My application does a good deal of binary serialization and compression of large objects. Uncompressed the serialized dataset is about 14 MB. Compressed it is arround 1.5 MB. I find that whenever I call the serialize method on my dataset my large…
Mark
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5 answers

questions about memory pool

I need some clarifications for the concept & implementation on memory pool. By memory pool on wiki, it says that also called fixed-size-blocks allocation, ... , as those implementations suffer from fragmentation because of variable block…
pepero
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How to prevent packet fragmentation for a HttpWebRequest

I am having a problem using HttpWebRequest against a HTTP daemon on an embedded device. The problem appears to be that there is enough of a delay between the http headers being written to the socket stream, and the http payload (a POST), that the…
piers7
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Android Heap Fragmentation Strategy?

I have an OpenGL Android app that uses a considerable amount of memory to set up a complex scene and this clearly causes significant heap fragmentation. Even though there are no memory leaks it is impossible to destroy and create the app without it…
chris
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How can I quickly detect and resolve SQL Server Index fragmentation for a database?

I've come across a situation where my database operations on many of my SQL Server database's tables have become very slow as more records have been added (5s for single insert to a table with 1 million records). I've estimated that this may be due…
Tommy Elliott
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RTP fragmentation vs UDP fragmentation

I don't understand why we bother fragmenting at RTP level if UDP (or IP) layer does the fragmentation. As I understand it, let's say we are on Ethernet link, the MTU is 1500 bytes. If I have to send, for example, 3880 bytes, fragmenting at IP…
xryl669
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MySQL Optimization 20 gig table

I have a 20 gig table that has a large amount of inserts and updates daily. This table is also frequently searched. I'd like to know if the MySQL indices can become fragmented and perhaps need to be rebuilt or something similar. I'm finding it…
user169743
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Reassembling fragmented UDP packet

I have a pcap of various types of traffic over 802.11 (wifi) over udf. The udp (or more precisely IP) fragments the wifi packets due to the MTU. I am currently using SharpPcap to read in and try and access the wifi traffic and am running into the…
user2731104
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Portable way to detect heap fragmentation in c++ at runtime?

I'm writing a qt-based c++ application and i need to be able to detect memory fragmentation in order to check if the current system can actually sustain the memory load: the program load a big image (15/21 megapixels are the norm) in memory and then…
Manuel
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Difference between skbuff frags and frag_list

The sk_buff has two places where it can store the next fragmentation data: skb_shinfo(head)->frag_list skb_shinfo(head)->frags[] What are the differences between these two ways to handle fragmentation?
Dien Nguyen
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Avoid memory fragmentation when memory pools are a bad idea

I am developing a C++ application, where the program run endlessly, allocating and freeing millions of strings (char*) over time. And RAM usage is a serious consideration in the program. This results in RAM usage getting higher and higher over time.…
Max Paython
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