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Tim Armstrong commented on ARROW-1588: -------------------------------------- Ah ok, makes sense. I don't know to what extent this applies but our experience is that decimal operations are a lot faster on narrower 4-byte and 8-byte representations. One reason is that the 4 byte and 8 byte decimal values fit in registers and can be manipulated with normal integer operations. A more subtle reason is that implementing some operations correctly (at least in Impala's implementation) requires temporarily promoting to a wider type, e.g. 4 byte -> 8 byte or 8 byte -> 16 bytes. Emulated 128-bit and 256-bit operations are pretty slow. > [C++/Format] Harden Decimal Format > ---------------------------------- > > Key: ARROW-1588 > URL: https://issues.apache.org/jira/browse/ARROW-1588 > Project: Apache Arrow > Issue Type: Improvement > Components: C++, Format > Affects Versions: 0.7.0 > Reporter: Phillip Cloud > Assignee: Phillip Cloud > Fix For: 0.8.0 > > > We should finalize and harden the decimal format. The remaining issues are > officially writing down the choice of making every decimal value 16 bytes and > byte order. > For byte order we'll need to run some benchmarks to compare little endian vs > big endian. I plan to work on this over the next week or two. > [~jacq...@dremio.com] [~wesmckinn] If there are any additional items you'd > like to see addressed here please chime in. -- This message was sent by Atlassian JIRA (v6.4.14#64029)