> ## Documentation Index > Fetch the complete documentation index at: https://docs.paradedb.com/llms.txt > Use this file to discover all available pages before exploring further. # Migrating from Elasticsearch > Feature comparison and migration guide for Elasticsearch users moving to ParadeDB This page is for developers who are evaluating or actively migrating from Elasticsearch (or OpenSearch) to ParadeDB. ParadeDB delivers Elastic-quality full-text search as a Postgres extension, so your data, queries, and infrastructure all live inside Postgres — no ETL pipelines, no separate cluster to manage. ## Key Differences | | Elasticsearch | ParadeDB | | ------------------- | -------------------------------------------- | ---------------------------------------------- | | **Query language** | JSON DSL | Standard SQL with search operators | | **Data model** | Denormalized documents | Normalized relational tables with JOINs | | **Transactions** | Per-document atomicity, eventual consistency | Full ACID transactions | | **Index storage** | Separate cluster | Inside Postgres (same database) | | **Schema changes** | Dynamic mapping or reindex | Defined at index creation; `REINDEX` to change | | **Updates/deletes** | Expensive (reindex internally) | Native Postgres operations | ## Migration Tips * **Start with your most common queries.** Map your highest-traffic Elasticsearch queries using the [full-text search reference](/documentation/full-text/overview). * **Use SQL JOINs instead of denormalization.** Elasticsearch requires denormalized documents, but ParadeDB supports full SQL JOINs. You can normalize your schema and simplify your data model. * **Continue to use Postgres tooling.** Backups, replication, monitoring, and CI/CD integrate with standard Postgres tools you already use. ## Feature Comparison ## Query Capabilities | Feature | Elasticsearch | ParadeDB | Notes | | --------------------------- | :-----------: | :------: | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Full-text search (BM25) | ✅ | ✅ | [Match and phrase operators](/documentation/full-text/overview) | | Fuzzy matching | ✅ | ✅ | Max edit distance of 2 via [`pdb.fuzzy()`](/documentation/full-text/fuzzy) | | Phrase matching | ✅ | ✅ | [`###` operator](/documentation/full-text/phrase) | | Phrase prefix | ✅ | ✅ | [`pdb.phrase_prefix()`](/documentation/query-builder/phrase/phrase-prefix) | | Regular expressions | ✅ | ✅ | [`pdb.regex()`](/documentation/query-builder/term/regex) | | Wildcard queries | ✅ | ✅ | Via [regex](/documentation/query-builder/term/regex) | | Boolean queries | ✅ | ✅ | Via SQL `AND`/`OR`/`NOT` or [`paradedb.boolean`](/documentation/query-builder/overview) | | Proximity search | ✅ | ✅ | [`##` operator](/documentation/full-text/proximity) | | More Like This | ✅ | ✅ | [`paradedb.more_like_this`](/documentation/query-builder/specialized/more-like-this) | | Nested queries | ✅ | ✅ | Via SQL [`JOIN`s](/documentation/joins/overview) | | Parent-child queries | ✅ | ✅ | Via SQL [`JOIN`s](/documentation/joins/overview) | | Geo queries | ✅ | ❌ | Use [PostGIS](https://postgis.net/) | | Percolator (reverse search) | ✅ | ❌ | | | Script-based scoring | ✅ | ❌ | | | Suggesters (autocomplete) | ✅ | ✅ | Via [search\_tokenizer](/documentation/tokenizers/search-tokenizer) (index with ngram, search with unicode) or [fuzzy prefix](/documentation/full-text/fuzzy#fuzzy-prefix) | ## Text Analysis | Feature | Elasticsearch | ParadeDB | Notes | | ------------------------------ | :-----------: | :------: | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Custom tokenizers | ✅ | ✅ | 12+ built-in [tokenizers](/documentation/tokenizers/overview) | | Token filters | ✅ | ✅ | 7 [filters](/documentation/token-filters/overview): [lowercase](/documentation/token-filters/lowercase), [stemmer](/documentation/token-filters/stemming), [stopwords](/documentation/token-filters/stopwords), [ascii\_folding](/documentation/token-filters/ascii-folding), [alpha\_num\_only](/documentation/token-filters/alphanumeric), [trim](/documentation/token-filters/trim), [token\_length](/documentation/token-filters/token-length) | | Character filters | ✅ | ❌ | | | Synonyms | ✅ | ⚠️ | Coming soon | | Different search-time analyzer | ✅ | ✅ | Via [search\_tokenizer](/documentation/tokenizers/search-tokenizer) or [multiple tokenizers per field](/documentation/tokenizers/multiple-per-field) | | Multi-language support | ✅ | ✅ | Chinese ([Jieba](/documentation/tokenizers/available-tokenizers/jieba)), Japanese/Korean ([Lindera](/documentation/tokenizers/available-tokenizers/lindera)), [ICU](/documentation/tokenizers/available-tokenizers/icu) | | Stemming | ✅ | ✅ | [19 languages](/documentation/token-filters/stemming) | | Stopwords | ✅ | ✅ | [29 languages](/documentation/token-filters/stopwords) | | N-gram tokenization | ✅ | ✅ | [Configurable](/documentation/tokenizers/available-tokenizers/ngrams) min/max gram size | ## Aggregations | Feature | Elasticsearch | ParadeDB | Notes | | ------------------------- | :-----------: | :------: | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Bucket aggregations | ✅ | ✅ | [terms](/documentation/aggregates/bucket/terms), [histogram](/documentation/aggregates/bucket/histogram), [date\_histogram](/documentation/aggregates/bucket/datehistogram), [range](/documentation/aggregates/bucket/range), [filters](/documentation/aggregates/bucket/filters) | | Metric aggregations | ✅ | ✅ | [avg](/documentation/aggregates/metrics/average), [sum](/documentation/aggregates/metrics/sum), [min/max](/documentation/aggregates/metrics/minmax), [count](/documentation/aggregates/metrics/count), [stats](/documentation/aggregates/metrics/stats), [percentiles](/documentation/aggregates/metrics/percentiles), [cardinality](/documentation/aggregates/metrics/cardinality), [top\_hits](/documentation/aggregates/metrics/tophits) | | Pipeline aggregations | ✅ | ✅ | Use SQL window functions (`SUM() OVER()`, `LAG()`, etc.) | | Nested aggregations | ✅ | ✅ | Use `pdb.agg()` with SQL `GROUP BY` | | ES-compatible JSON syntax | — | ✅ | [`pdb.agg()`](/documentation/aggregates/overview) accepts ES JSON directly | | SQL GROUP BY | Limited | ✅ | Full SQL aggregation support | Since `pdb.agg()` accepts Elasticsearch-compatible JSON, many of your existing aggregation queries can be migrated with minimal changes. See the [aggregates documentation](/documentation/aggregates/overview). ## Scoring and Relevance | Feature | Elasticsearch | ParadeDB | Notes | | ------------------ | :-----------: | :------: | -------------------------------------------------------------------------------------------------------------------------- | | BM25 scoring | ✅ | ✅ | [`pdb.score()`](/documentation/sorting/score) | | Custom boost | ✅ | ✅ | [`pdb.boost()`](/documentation/sorting/boost) type cast | | Constant score | ✅ | ✅ | [`pdb.const()`](/documentation/sorting/boost#constant-scoring) | | Disjunction max | ✅ | ✅ | `paradedb.disjunction_max()` | | Function score | ✅ | ❌ | Use [boost](/documentation/sorting/boost) / [const](/documentation/sorting/boost#constant-scoring) as partial alternatives | | Script scoring | ✅ | ❌ | | | Decay functions | ✅ | ❌ | | | Field value factor | ✅ | ❌ | | ## Highlighting | Feature | Elasticsearch | ParadeDB | Notes | | -------------------- | :-----------: | :------: | ---------------------------------------------------------------------------- | | Snippet highlighting | ✅ | ✅ | [`pdb.snippet()`](/documentation/full-text/highlight) | | Multiple snippets | ✅ | ✅ | [`pdb.snippets()`](/documentation/full-text/highlight#multiple-snippets) | | Custom tags | ✅ | ✅ | `start_tag`, `end_tag` parameters | | Byte offsets | ❌ | ✅ | [`pdb.snippet_positions()`](/documentation/full-text/highlight#byte-offsets) | | Fuzzy highlighting | ✅ | ❌ | | ## Index Management | Feature | Elasticsearch | ParadeDB | Notes | | ----------------- | :-----------: | :------: | ----------------------------------------------------------------------------------- | | Create index | ✅ | ✅ | [`CREATE INDEX ... USING bm25`](/documentation/indexing/create-index) | | Drop index | ✅ | ✅ | `DROP INDEX` | | Reindex | ✅ | ✅ | [`REINDEX`](/documentation/indexing/reindexing) | | Index aliases | ✅ | ✅ | Via Postgres views | | Index templates | ✅ | ❌ | | | Dynamic mapping | ✅ | ❌ | Schema defined at index creation; requires `REINDEX` to change | | Multi-field index | ✅ | ✅ | All columns included in [one index per table](/documentation/indexing/create-index) | ## Data Operations | Feature | Elasticsearch | ParadeDB | Notes | | ------------------ | :-----------: | :------: | ------------------------------------------------------------------------------------- | | ACID transactions | ❌ | ✅ | Full Postgres ACID compliance | | Real-time indexing | ⚠️ | ✅ | ES is near-real-time (requires refresh); ParadeDB provides immediate read-after-write | | JOINs | ❌ | ✅ | Full SQL [JOIN](/documentation/joins/overview) support | | UPDATE / DELETE | ⚠️ | ✅ | ES internally reindexes; Postgres handles natively | | Bulk insert | ✅ | ✅ | [`COPY` or batch `INSERT`](/documentation/performance-tuning/writes) | | SQL queries | ❌ | ✅ | Full SQL including subqueries, CTEs, window functions | ## Deployment and Operations | Feature | Elasticsearch | ParadeDB | Notes | | -------------------------- | :-----------: | :------: | -------------------------------------------------------------------------- | | Horizontal sharding | ✅ | ⚠️ | Via [Citus](/deploy/citus) for distributed workloads | | Read replicas | ✅ | ✅ | Postgres streaming replication | | Kubernetes | ✅ | ✅ | [CNPG / Helm charts](/deploy/self-hosted/kubernetes) | | Docker | ✅ | ✅ | [Official Docker image](/documentation/getting-started/install) | | Logical replication ingest | ❌ | ✅ | [Sync from existing Postgres](/deploy/logical-replication/getting-started) | | Cross-cluster search | ✅ | ❌ | | | Snapshot / restore | ✅ | ✅ | Via Postgres backup tools (pg\_dump, WAL archiving) | | Monitoring | ✅ | ✅ | pg\_stat, pganalyze, standard Postgres tools | ## Pagination | Feature | Elasticsearch | ParadeDB | Notes | | ------------------ | :-----------: | :------: | ---------------------------------------------------------------- | | `from` / `size` | ✅ | ✅ | SQL `LIMIT` / `OFFSET` | | `scroll` API | ✅ | ❌ | Use SQL cursors (`DECLARE` / `FETCH`) instead | | `search_after` | ✅ | ❌ | Use keyset pagination (`WHERE id > last_id ORDER BY id`) instead | | Top K optimization | ✅ | ✅ | [`paradedb.limit_fetch_multiplier`](/documentation/sorting/topk) |