Michael Smith has posted comments on this change. ( http://gerrit.cloudera.org:8080/24504 )
Change subject: IMPALA-15101: Add UUID primitive type to Impala ...................................................................... Patch Set 4: Code-Review+1 (1 comment) > Patch Set 4: > > (1 comment) > > > https://gerrit.cloudera.org/c/24567/ looks somewhat related, and > > leverages a StringSubtype on column types to touch less code. Could > > we do something similar here? > > I wouldn't recommend this as: > 1. IMPALA-15158’s StringValSubtype pattern fits types that piggy-back on > TYPE_STRING , heap allocated StringValue, same as BINARY/GEOMETRY while in > case of UUID we store 16 raw bytes inline in the tuple slot (like CHAR). > 2. Folding UUID into string + subtype would mean either carrying 36-char heap > strings or 16-byte heap blobs and both add per-value allocation and make > compare/order/hash/aggregates complex. > 3. We’d still need format-specific read logic (Parquet FIXED_LEN_BYTE_ARRAY, > ORC BINARY + iceberg attribute, Avro FIXED(16)), so the line diff savings > wouldn't be worth letting go of cheap `memcmp` ordering, no allocation on > scan/join/agg. > 4. As Zoltan mentioned in the previous commit, having it in inline slots > makes the read/write path simpler too with `memcpy` and no allocation/free. Makes sense, thanks for looking into it. http://gerrit.cloudera.org:8080/#/c/24504/3/be/src/runtime/types.h File be/src/runtime/types.h: http://gerrit.cloudera.org:8080/#/c/24504/3/be/src/runtime/types.h@149 PS3, Line 149: static ColumnType CreateBinaryType() { > Passing TYPE_UUID in the constructor would require dropping the safeguard o Ack -- To view, visit http://gerrit.cloudera.org:8080/24504 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Iefc73aefe73b6144c929ec37b0cb333007cf8bfe Gerrit-Change-Number: 24504 Gerrit-PatchSet: 4 Gerrit-Owner: Arnab Karmakar <[email protected]> Gerrit-Reviewer: Arnab Karmakar <[email protected]> Gerrit-Reviewer: Csaba Ringhofer <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Michael Smith <[email protected]> Gerrit-Reviewer: Zoltan Borok-Nagy <[email protected]> Gerrit-Comment-Date: Fri, 17 Jul 2026 18:45:27 +0000 Gerrit-HasComments: Yes
