Elasticsearch vs. PostgreSQL Full-Text: Search Engine Indexing Deep Dive

Every search engine needs an index. The question is: which technology builds it?

PostgreSQL Full-Text Search

Built-in since PostgreSQL 8.3. Surprisingly capable.

Pros:

Zero additional infrastructure

ACID compliance (index stays consistent with data)

Good for < 1M documents

Supports German stemming, compound word handling

tsvector/tsquery is fast for simple needs

Cons:

No distributed search

Limited faceting and aggregation

Relevance scoring is basic

No built-in synonym support

Elasticsearch

The industry standard for search.

Pros:

Distributed by design (shards, replicas)

Advanced relevance scoring (BM25, custom functions)

Real-time indexing

Faceting, aggregation, geospatial

Plugin ecosystem (synonyms, analyzers)

Cons:

Additional infrastructure (cluster management)

Memory hungry (heap size tuning required)

Eventually consistent (not ACID)

Complex query DSL learning curve

What We Chose (and Why)

We use both…