We're thrilled to announce the official release of GreptimeDB v0.16! This version focuses on comprehensive enhancements to PromQL support and native database observability, empowering users with more robust and flexible time-series data processing capabilities.

Development Overview

From v0.15 to v0.16, the Greptime team and community contributors have achieved remarkable progress together:

Development Statistics

• 60 commits successfully merged
• 19 individual contributors participated
• 2 first-time contributors joined the project

Improvement Distribution

• 36 feature enhancements: Including PromQL integration, TQL CTE support, and observability upgrades
• 12 bug fixes: Improved system stability and robustness
• 5 code refactoring efforts: Optimized code architecture and maintainability
• 1 performance optimization: Increased execution efficiency
• 6 miscellaneous tasks: Dependency upgrades, documentation improvements, etc.

👏 Special thanks to the 19 individual contributors for their dedication and a warm welcome to the 2 new community members who joined us! We welcome more developers interested in observability database technology to join the GreptimeDB community.

Core Feature Highlights

Dashboard v0.10.6 Released

• Sidebar controls: Toggle visibility from left menu and persist tables sidebar width

• Full-screen data view: Immersive analytics experience for query results

• Log/Trace view redesign: Upgraded UI and performance for log/trace inspection

PromQL Enhancements

• Added the absent() function and other scalar functions to further improve compatibility with OLTP metrics.

Observability Upgrades

• Added Panic log recording mechanism

• HTTP API-level heap profiling (enabled via memory.enable_heap_profiling config)

• Enhanced EXPLAIN ANALYZE VERBOSE output:

  • Added region-level metrics in MergeScanExec (rows/batches/bytes processed)
  • Scanners now emit verbose logs in debug mode
  • RegionScanExec supports verbose flags

CREATE DATABASE supports WITH keyword configuration

Like CREATE TABLE, now supports configuration via WITH clause.

For example, the following SQL statement creates a database with multiple options, including an append-only mode and a custom memtable type:

CREATE DATABASE test WITH (
  ttl='30d',
  'memtable.type'='partition_tree',
  'append_mode'='true'
);

The database currently supports the following configuration options:

• ttl: Data time-to-live for all tables (cannot be set to instant)
• memtable.type: In-memory table type (time_series, partition_tree)
• append_mode: Whether tables in the database use append-only mode (true/false)
• merge_mode: Strategy for merging duplicate rows (last_row, last_non_null)
• skip_wal: Whether to disable write-ahead logging for tables in the database (true/false)
• compaction.*: Compression-related settings (e.g. compaction.type, compaction.twcs.time_window)

ALTER TABLE Column Defaults

Notably, this enhancement to the ALTER TABLE command was independently developed and contributed by @linyihai, an independent contributor from the GreptimeDB community!

Specific capabilities include:

• Set a default value for an existing column

ALTER TABLE monitor MODIFY COLUMN load_15 SET DEFAULT 0.0;

• Set a default string value

ALTER TABLE monitor MODIFY COLUMN `status` SET DEFAULT 'active';

When inserting new rows without explicitly assigning a value to this column, it will be populated with the default value.

• Remove the default value from a column

ALTER TABLE monitor MODIFY COLUMN load_15 DROP DEFAULT;

After removing the default value, the column will default to NULL; this operation is only permitted on nullable columns.

Upgrade Guide

Compatibility

• v0.16 maintains full data/config compatibility with v0.15

• Recommended for all v0.15 users

Upgrade Instructions

• For detailed upgrade steps, please refer to the Upgrade Documentation.

• For upgrades from older versions, please consult the corresponding version upgrade documentation.

Future Roadmap

As outlined in v0.15, we remain focused on:

• Feature refinement: Optimizing user experience

• Performance optimization: Improving system efficiency

• Reliability and stability enhancements: Building enterprise-grade product standards

These efforts will establish a solid foundation for GreptimeDB v1.0 release.

Once again, we extend our heartfelt gratitude to the Greptime team, contributors, and advocates! We look forward to welcoming more developers to join the GreptimeDB community and collectively advance observability database technology.