ClickHouse TTL: Merge-Driven Retention, Not a Cron Job
TTL in ClickHouse is evaluated per-part during background merges, not by a cron job. Learn how to compile a 30-day drop policy, verify with system.ttl, and avoid common pitfalls.
Loading…
ReadMeFeed / Community knowledge
#data-retention
Real questions. Useful conversations. Find the people who know your stack.
ClickHouse TTL: Auto‑Purge Old Data Without Housekeeping Scripts
ClickHouse’s TTL clause automatically purges old rows from MergeTree tables, eliminating manual cleanup scripts. Learn how to set it up, monitor it, and avoid common pitfalls in this concise guide.
Designing a Kafka Topic with Log Compaction: Requirements, Minimal Setup, Boundaries, Checks, and Failure Modes
Learn how to size partitions, set compaction triggers, and monitor lag so that Kafka log compaction retains only the latest value per key without unexpected latency or storage spikes.
apachekafkaAutomating Elasticsearch Index Management with ILM: Rollover, Shrink, and Delete
Learn how to configure Elasticsearch Index Lifecycle Management to automate rollover, shrink, and deletion of indices. Follow a step‑by‑step guide, verify with APIs, and recover if something goes wrong.
elasticsearchMongoDB TTL Indexes: Let the Database Delete Your Expired Data (With Caveats)
MongoDB TTL indexes delete expired documents for you — no cron job required. Here's how they work, a working configuration, and the operational caveats that matter before you rely on them.
mongodbManaging Storage Costs with InfluxDB Retention Policies
Learn how to implement and manage InfluxDB Retention Policies to automate data expiration, control disk usage, and balance historical data needs against storage costs.
Let MongoDB Delete Your Expired Data: TTL Indexes as an Engineering Decision
MongoDB TTL indexes delete expired sessions, tokens, and logs for you — no cron job required. Here's how they work, where they fall short, and how to verify them.
Setting Up ClickHouse TTL Policies to Expire Old Data Automatically
How to configure ClickHouse TTL expressions on MergeTree tables to delete or relocate aged data, verify expiration through system tables, and recover from a misfiring policy.
clickhouseArchitecting Long-Term Retention with Apache Pulsar Tiered Storage
Learn how to implement Apache Pulsar Tiered Storage to decouple data retention from compute costs while maintaining transparent data access via object stores.