solid-state storage & dbms
DESCRIPTION
Solid-state storage & DBMS. CIDR 2013 Manos Athanassoulis. Flash is replacing disks. Flash not a drop-in replacement for disks . But, random writes on flash Instability in performance Shorter device lifetime And flash capacity is expensive - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/1.jpg)
Solid-state storage & DBMS
CIDR 2013Manos Athanassoulis
1
![Page 2: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/2.jpg)
2
Flash is replacing disksBut, random writes on flash
– Instability in performance– Shorter device lifetime
And flash capacity is expensive
Is flash ready/suitable for secondary storage?Reverse: How can DBMS exploit flash?
Flash not a drop-in replacement for disks
![Page 3: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/3.jpg)
3
Disks all over the place• DBMS modules assumes disks
– Storage– Buffer management– Indexing– Logging
• Lower-level: – Block APIs – Storage software stack
Re-architect DBMS needed for solid-state storage
Buffers
![Page 4: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/4.jpg)
4
How to use flash in a “disk-world”?
Buffers
![Page 5: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/5.jpg)
5
How to use flash in a “disk-world”? • As a specialized write cache
– Hides update overhead
Updates
Buffers
![Page 6: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/6.jpg)
6
How to use flash in a “disk-world”? • As a specialized write cache
– Hides update overhead
• As secondary storage– Offers efficient random access
Buffers
![Page 7: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/7.jpg)
7
How to use flash in a “disk-world”? • As a specialized write cache
– Hides update overhead
• As secondary storage– Offers efficient random access
• As a “regular” cache level
Buffers
SSDBuffer
![Page 8: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/8.jpg)
Flash, solid-state, DBMS:The challenges are far from done …
8
![Page 9: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/9.jpg)
9
Flash Wall
Capacity: Density will plateau (soon)Endurance (already)
![Page 10: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/10.jpg)
10
PCM, memristor and co
More than flash:How to use persistent main memory?
![Page 11: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/11.jpg)
11
Software stack is too slow
HDD Flash PCM10
100
1000
100004000
50
17
17 17 17
Late
ncy
(μs)
Device Latency (H/W)
OS & FS Latency (S/W)
![Page 12: Solid-state storage & DBMS](https://reader035.vdocuments.site/reader035/viewer/2022062323/56816385550346895dd46e52/html5/thumbnails/12.jpg)
12
Flash Wall(s)Persistent main memory
OS & FS too slow
Thank you!
Manos Athanassoulis