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Cassandra

Design Cassandra tables, write efficient queries, and avoid distributed database pitfalls.

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High Signal

Design Cassandra tables, write efficient queries, and avoid distributed database pitfalls.

⬇ 0 downloads ★ 0 stars Unverified but indexed

Install for OpenClaw

Quick setup
  1. Download the package from Yavira.
  2. Extract the archive and review SKILL.md first.
  3. Import or place the package into your OpenClaw setup.

Requirements

Target platform
OpenClaw
Install method
Manual import
Extraction
Extract archive
Prerequisites
OpenClaw
Primary doc
SKILL.md

Package facts

Download mode
Yavira redirect
Package format
ZIP package
Source platform
Tencent SkillHub
What's included
SKILL.md

Validation

  • Use the Yavira download entry.
  • Review SKILL.md after the package is downloaded.
  • Confirm the extracted package contains the expected setup assets.

Install with your agent

Agent handoff

Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually.

  1. Download the package from Yavira.
  2. Extract it into a folder your agent can access.
  3. Paste one of the prompts below and point your agent at the extracted folder.
New install

I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Tell me what you changed and call out any manual steps you could not complete.

Upgrade existing

I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Summarize what changed and any follow-up checks I should run.

Trust & source

Release facts

Source
Tencent SkillHub
Verification
Indexed source record
Version
1.0.0

Documentation

ClawHub primary doc Primary doc: SKILL.md 11 sections Open source page

Data Modeling Mistakes

Design tables around queries, not entities—denormalization is mandatory, not optional One table per query pattern—Cassandra has no JOINs; duplicate data across tables Partition key determines data distribution—all rows with same partition key on same node Wide partitions kill performance—keep under 100MB; add time bucket to partition key if growing

Primary Key Traps

PRIMARY KEY (a, b, c): a is partition key, b and c are clustering columns PRIMARY KEY ((a, b), c): (a, b) together is partition key—compound partition key Clustering columns define sort order within partition—query must respect this order Can't query by clustering column without partition key—unlike SQL indexes

Query Restrictions

WHERE must include full partition key—partial partition key fails unless ALLOW FILTERING ALLOW FILTERING scans all nodes—never use in production; redesign table instead Range queries only on last clustering column used—WHERE a = ? AND b > ? works, WHERE a = ? AND c > ? doesn't IN on partition key hits multiple nodes—expensive; prefer single partition queries

Consistency Levels

QUORUM for most operations—majority of replicas; balances consistency and availability LOCAL_QUORUM for multi-datacenter—avoids cross-DC latency ONE for pure availability—may read stale data; fine for caches, bad for critical reads Write + read consistency must overlap for strong consistency—QUORUM + QUORUM safe

Tombstones (Silent Performance Killer)

DELETE creates a tombstone, not actual deletion—tombstones persist until compaction Mass deletes destroy read performance—thousands of tombstones scanned per query TTL also creates tombstones—don't use short TTLs with high write volume Check with nodetool cfstats -H table—Tombstone columns show problem

Batch Misuse

UNLOGGED BATCH is not faster—use only for atomic writes to same partition LOGGED BATCH for multi-partition atomicity—adds coordination overhead Don't batch unrelated writes—hurts coordinator; send individual async writes Batch size limit ~50KB—larger batches fail or timeout

Anti-Patterns

Secondary indexes on high-cardinality columns—scatter-gather query, slow Secondary indexes on frequently updated columns—creates tombstones SELECT *—always list columns; schema changes break queries UUID as partition key without time component—random distribution, hot spots during bulk loads

Lightweight Transactions

IF NOT EXISTS / IF column = ?—uses Paxos, 4x slower than normal write Serial consistency for LWTs—SERIAL or LOCAL_SERIAL Don't use for counters or high-frequency updates—contention kills throughput Returns [applied] boolean—must check if operation succeeded

Collections and Counters

Sets/Lists/Maps stored with row—can't exceed 64KB, no pagination List prepend is anti-pattern—creates tombstones; use append or Set Counters require dedicated table—can't mix with regular columns Counter increment is not idempotent—retry may double-count

Compaction Strategies

SizeTieredCompactionStrategy (default)—good for write-heavy, uses more disk space LeveledCompactionStrategy—better read latency, higher write amplification TimeWindowCompactionStrategy—for time-series with TTL; reduces tombstone overhead Wrong strategy for workload = degraded performance over time

Operations

nodetool repair regularly—inconsistencies accumulate without repair nodetool status shows cluster health—UN (Up Normal) is good, DN is down Schema changes propagate eventually—wait for nodetool describecluster to show agreement Rolling restarts: one node at a time, wait for UN status before next

Category context

Agent frameworks, memory systems, reasoning layers, and model-native orchestration.

Source: Tencent SkillHub

Largest current source with strong distribution and engagement signals.

Package contents

Included in package
1 Docs
  • SKILL.md Primary doc