Compatibility and limitations
On this page
- Query language
- Values and indexes
- Graph data science and APOC
- Transactions and scale
- Protocol and administration
Use this guide to check your application's queries and driver compatibility when evaluating a Galactus DB release.
Query language
Supported: read/write patterns, optional matches, MERGE, list/pattern comprehensions, CASE, reduce, FOREACH, map projection, XOR, inline WHERE, aggregates including DISTINCT, EXISTS/COUNT pattern subqueries, LOAD CSV, CALL/YIELD and serial CALL IN TRANSACTIONS. See Cypher.
Remaining limits include =~ and regex APOC functions, COLLECT { ... },
quantified GQL path syntax, concurrent batched subqueries and ON ERROR batch
policies. Strings use functions such as substring; list subscript/slice syntax
does not apply to strings. PROFILE executes queries, including writes, without
per-operator timing metadata; EXPLAIN does not execute them.
Values and indexes
All six temporal types and named IANA DateTime zones are supported; the vendored zone table covers 1900–2100. Time-of-day zones remain offset-only. See temporal edge cases, including duration aliases and ignored truncation overrides. Geometry and geography now support all seven linear shape families, strict WKT/WKB/GeoJSON, predicates, overlays and centroid alongside legacy points. Computations require XY; geographic overlays generally need a common open hemisphere. Polar GeoJSON export, ellipsoidal operations and coordinate reprojection are unsupported. See spatial shapes.
Hash, range, composite, element, vector, point, spatial shape and full-text indexes are implemented. Constraints cover ordinary/group/element uniqueness, existence and node keys. Relationship property indexes and property-type constraints are absent. HNSW is approximate: exact rescoring orders only the candidates found, and cannot guarantee full-search recall. Full-text is BM25 bag-of-words with OR semantics; no phrase, fuzzy, stemming, boolean-query or highlighting support. See index selection.
Shape indexes require an explicit db.index.spatial.intersects call; spatial
WHERE clauses do not automatically select them. Cartesian envelopes prune
candidates; geographic indexes currently refine a scan. Drivers receive a
versioned map envelope for spatial shapes and can import it with spatial.fromMap.
Graph data science and APOC
Native database-scoped projections support centrality, similarity/KNN, FastRP, community algorithms including Label Propagation and Leiden, and pathfinding. Personalised PageRank, native projection estimates, budget checks and cooperative cancellation are implemented. FastRP/PageRank accept opt-in parallel execution; default concurrency is 1. Other algorithms remain serial, and KNN accepts only 1. See algorithm modes and resource controls.
No persistent graph catalogue, Cypher projections, ML pipelines, model catalogue
or remote named-job cancellation. Unsupported configuration keys raise errors.
Seeds and community IDs are implementation-specific; compare documented semantics
and partitions. Results, including .stream, are materialised in the query result.
APOC includes scalar functions, traversal, exact metadata scans, dynamic create/merge, mergeNodes and selected JSON/Cypher interchange. It has no plugin loader, periodic background jobs, general refactor suite or JSONPath. Files and plain HTTP are supported import sources; HTTPS is not. File export effects are not rolled back with graph mutations. See APOC and imports.
Transactions and scale
Concurrent read statements share the database gate. Write execution is exclusive; readers wait for an open writer. Read-mode sessions overlap but do not capture a repeatable-read snapshot at BEGIN. There is no full MVCC or concurrent write execution. Group commit shares syncs between concurrent clients; it does not parallelise mutation execution. See transactions.
Hybrid mode bounds decoded base-property caching, while topology, adjacency, property locations and derived indexes remain in RAM. This is not a fully paged database. Hybrid checkpoints incrementally compact stale values, but structural history remains until a logical dump/restore. Resident checkpoints write the whole graph. One process must own each durable directory; the built-in duplicate open guard covers handles in one process, not other OS processes.
Protocol and administration
The server speaks Bolt 4.4 with a single-node routing table, not a replicated
cluster. The native 0.1 drivers negotiate 4.4 and use direct connections; they do
not implement routing, pooling, managed retries or lazy cursors. They buffer
records and support explicit transactions and native type mapping. See
driver setup and limits. Other clients must negotiate 4.4. Some DBMS listing procedures return
empty compatibility rows. db.indexes() and db.constraints() are incomplete
legacy catalogues; use SHOW statements for schema audits.
Basic HELLO authentication is mandatory. Users, roles and whole-database grants persist in the protected system database. System administration privileges are separate; label and property restrictions remain deferred. Server passwords use Argon2id. There is no native TLS. See authentication. Explorer connects remotely over Bolt.