Checkpoints

Non-Blocking Fuzzy

It follows PostgreSQL.

Concurrency Control

Multi-version Concurrency Control (MVCC) Two-Phase Locking (Deadlock Detection)

It supports transactions on a per-server basis. Like PostgreSQL, it uses MVCC and Serializable Snapshot Isolation (SSI). It also supports explicit locking with deadlock detection.

Data Model

Relational

It follows PostgreSQL

Foreign Keys

Supported

It follows PostgreSQL.

Indexes

B+Tree Hash Table BitMap

It follows PostgreSQL, which has primary, secondary, derived, partial indexes. PostgreSQL supports B-tree, hash, GiST, SP-GiST, GIN, and BRIN indexes, and default is B-tree.

Isolation Levels

Read Uncommitted Read Committed Serializable Repeatable Read

It follows PostgreSQL, which supports Read uncommitted, Read committed, Repeatable read, Serializable. Read Committed is the default. They are implemented with MVCC. Note that PostgreSQL's Read Uncommitted is in fact Read Committed.

Joins

Nested Loop Join Hash Join Sort-Merge Join Semi Join

It follows PostgreSQL.

Logging

Logical Logging Physical Logging

It follows PostgreSQL.

Query Compilation

Not Supported

Not Supported

Query Execution

Tuple-at-a-Time Model

Query Interface

SQL PL/SQL PromQL

Since TimescaleDB is based on Postgres, it supports Postgres' SQL and PL/pgSQL interfaces. They also provide support for PromQL through a Prometheus adapter.

Storage Architecture

Disk-oriented

It follows PostgreSQL

Storage Model

N-ary Storage Model (Row/Record)

It follows PostgreSQL

Stored Procedures

Supported

It follows PostgreSQL.

System Architecture

Shared-Everything

Like Postgres, TimeScale is a shared-everything DBMS. Each table is partitioned across all space and time intervals.

Views

Virtual Views Materialized Views

It follows PostgreSQL.