[HIVE-16151] BytesBytesHashTable allocates large arrays

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Assignee: Sergey Shelukhin
• Reporter: Prasanth Jayachandran
• Created: 09/Mar/17 00:22
• Updated: 30/May/17 19:40

Description

These arrays cause GC pressure and also impose key count limitations on the table. Wrt the latter, we won't be able to get rid of it without a 64-bit hash function, but for now we can get rid of the former. If we need the latter we'd add murmur64 and probably account for it differently for resize (we don't want to blow up the hashtable by 4 bytes/key in the common case where #of keys is less than ~1.5B )