[LUCENE-6199] Reduce per-field heap usage for indexed fields

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 5.2, 6.0
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Michael McCandless
• Created: 26/Jan/15 10:13
• Updated: 28/Aug/22 14:24

Description

Lucene uses a non-trivial baseline bytes of heap for each indexed
field, and I know it's abusive for an app to create 100K indexed
fields but I still think we can and should make some effort to reduce
heap usage per unique field?

E.g. in block tree we store 3 BytesRefs per field, when 3 byte[]s
would do...

Sub-Tasks

• Fix readStringStringMap api: Closed
• re-use immutable maps across fieldinfos when they are the same: Closed
• improve perf and memory of FieldInfos.fieldInfo(int): Closed