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A link references an already existing file either by means of pointing to the same blocks on disk as the original file (hard link) or a pointer that points to the original file (symbolic link). Symbolic links may cross filesystem boundaries whereas hard links may not. See ln(1). (named) pipes and (UNIX domain) sockets are methods of interprocess communication, used to exchange information between processes running on the same machine (in contrast to processes running on separate machines using the network to communicate). See pipe(2), socket(2) and associated manual pages for more in-depth information on how to use these. As for the other non-text type files... plenty... almost any file format carrying data of some sort that is not text, i.e. executable files, audio-, video- and all kinds of other data files.What are link, pipe and socket files and how to use them?
and what are non-text type of files that I dont know of?
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What? That's new to me. I still read the recommendation to give the DB access to the raw disk/SSD (if speed is not sufficient w/ the standard file method) quite often.[...] Until about 15-20 years ago, databases commonly used disks (or disk partitions) directly, without going through a file system. That usage is historic today. [...]
Iff the amount of data is so huge that you need several physical media to store it anyway, I do not see any loss of convenience. Just mirror the whole disks in a RAID-10 (e.g. graid(8) or gvinum(8)), insert a gsched(8) IO-scheduler (a geom_cksum(4) is not available yet), done. On your measurements: the performance of DB differs significantly with the use-case. In general, when latency is of primary concern, using raw disks can make a big difference.They're still recommending to use raw disk? Serious? I stand corrected. Those fools. For a small performance gain (we measured it in the last 90s, and it was a handful percent), you lose a lot of convenience. But it's a free country ... do as you please.
It's a real barrel of laughs when the ignorant Oracle DBAs insist on using ASM on top of virtual disk.They're still recommending to use raw disk? Serious? I stand corrected. Those fools. For a small performance gain (we measured it in the last 90s, and it was a handful percent), you lose a lot of convenience. But it's a free country ... do as you please.