This document describes Schema Training Mode in Solr, which allows users to train a schema by learning from data without indexing it. The mode suggests the most suitable field type, whether fields are single or multi-valued, and can point out type anomalies. It is useful for multi-tenant search platforms, indexing from multiple sources, getting started with Solr, and understanding one's data. The mode provides APIs to start and stop training and get the trained schema.

1. Schema Training Mode.
How to Train Your Schema?
Related JIRAS: (SOLR-11741, SOLR-6939)

2. WHAT IS SCHEMA?
A mapping between the fieldName and it’s Type.
SOLR needs a schema to define what type each field
belongs to. Internally it maps these types to Lucene
Types.
FieldName title price id
FieldType String Float String

3. SCHEMA LESS SOLR?
SOLR can’t function properly without a schema.
So, it comes with a Schema-less Mode that builds an
schema in the background as you index.
However, It has it’s own problems.…

4. Indexing Document in SchemaLess Mode
Doc 1:
{“title”:“Fantastic Beasts”, “price”:200,“distID”:”2017-01-07”}
Doc 2:
{“title”:“Train Your Dragon”, “price”:22.3, “distID”:”112-uuiw-0”}
Fails With Errors:
Float not supported for fieldType Long!!
String not supported for fieldType Date!!
FieldNames title price distId
TypesInferred String Long Date

5. WHAT IF…
We could train our schema based on the data that we
have?

6. INTRODUCING…
Schema Training Mode
A set of APIs that lets you create a schema by
learning from your data, without indexing it.

7. WHAT CAN IT DO?
Learn from the document stream, and suggest the
following for every field:-
The Most Suitable FieldType
SingleValued or MultiValued
Point-out possible ‘type-anomalies’ in a document
stream.

8. WHO NEEDS IT
Multi Tenant Search Platforms
Indexing Documents from Multiple Sources
Getting an Idea of Your Data
Getting started with SOLR

9. SCHEMA-TRAINING API’S
1. Get A Training ID:
POST: /schema/train/start
Response: <NewTrainingID>
2. Start Training:
POST: /schema/train/<trainingID> -d [{f1:v1, f2:v2…}]
3. Get The Schema Trained So Far:
GET: /schema/train/<trainingID>/trainedSchema
Response: {Generated Schema}
4. Stop The Training:
DELETE: /schema/train/<trainingID>

10. FIELD-HIERARCHY-TREE
String
Double
Long
BooleanDate
Level

11. FIELD-HIERARCHY-TREE

12. TO DO…
Replay the data internally to index it.
Learn from the queries and suggest:
Most suitable field types (string field vs. text field)
DocValues: true vs. false
Stored: true vs. false
Default search fields (qf)

13. QUESTIONS?