ER ERMIA: IA: Fast t Mem emor ory-Op Optimi mized Da - PowerPoint PPT Presentation

ER ERMIA: IA: Fast t Mem emor ory-Op Optimi mized Da Database se System em for or He Heter erogen eneo eous Wo Workloads Authors: Kangnyeon Kim, Tianzheng Wang, Ryan Johnson, Ippokratis Pandis Presented by: Fengjian Pan Some slides contains material from the original authors’ slides.

GAP SILO: Lightweight OCC Read version Writes wins over read Fence Read Data Fence No, abort Commit Time Same Read Version Yes, commit Version?

ERMIA Key Principles • Latch-free indirection arrays • Provide low overhead multi-versioning. • Snapshot-isolation(SI) • Fairness between read and write • Early detection of doomed transaction • Serial Safety Net(SSN) • Provide serializability on top of SI.

Snapshot-Isolation(SI) Read Is V1 older than transaction? && V1 is not No, check next one dirty Yes, read V1 V2 V3 New Old

Snapshot-Isolation(SI) Write Yes, abort Read and write never block each other Is V1 Dirty? No, append a new version V1 V2 V3 New Old

Serial Safety Net(SSN)

Benchmarks

Conclusion • The ERMIA provides • Reasonable performance on traditional workflow. • Better performance on read-most workflow compare to using lightweight OCC.