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We've been using ClickHouse ReplacingMergeTree tables for updates without any issues...in fact, they've been more than reliable for our use case. For us, as lon

We've been using ClickHouse ReplacingMergeTree tables for updates without any issues...in fact, they've been more than reliable for our use case. For us, as long as updated data is visible within 15–30 minutes, that's acceptable. What's your ingest vs. update volume per hour and per minute?

jauntywundrkind 1y ago
There's also the new CoalescingMergeTree, that seems very useful for many classic roll-up problems, ideal for materializing a recent view of the append only log of data that is ClickHouse's natural append-only log strong point. https://clickhouse.com/blog/clickhouse-25-6-coalescingmergetree https://clickhouse.com/blog/clickhouse-25-6-coalescingmerget... https://news.ycombinator.com/item?id=44656436 https://news.ycombinator.com/item?id=44656436 For general mutable data, ClickHouse is trying super hard to get much better & doing amazing engineering. But it feels like it'll be a long time before the fortress of Postgres for OLTP is breached. https://about.gitlab.com/blog/two-sizes-fit-most-postgresql-and-clickhouse/ https://about.gitlab.com/blog/two-sizes-fit-most-postgresql-... https://news.ycombinator.com/item?id=44895954 https://news.ycombinator.com/item?id=44895954 The top submission is the end of a 4 part series. Part two is really nice on the details of how ClickHouse has focused on speeding updates: recommend a read! https://clickhouse.com/blog/updates-in-clickhouse-2-sql-style-updates https://clickhouse.com/blog/updates-in-clickhouse-2-sql-styl...
- djfobbz 1y ago
  I agree, I’ve been on CH since v20 and I thought I was the only one who noticed that they’ve been working very hard to bridge the gap between OLAP and OLTP. Sure, they’ll always be first class OLAP DB…but if you know how to get dangerous with its strengths, making it the goto datalake for your existing OLTP is pretty freaking awesome. Thanks for those shares

jauntywundrkind 1y ago

There's also the new CoalescingMergeTree, that seems very useful for many classic roll-up problems, ideal for materializing a recent view of the append only log of data that is ClickHouse's natural append-only log strong point. https://clickhouse.com/blog/clickhouse-25-6-coalescingmergetree https://clickhouse.com/blog/clickhouse-25-6-coalescingmerget... https://news.ycombinator.com/item?id=44656436 https://news.ycombinator.com/item?id=44656436 For general mutable data, ClickHouse is trying super hard to get much better & doing amazing engineering. But it feels like it'll be a long time before the fortress of Postgres for OLTP is breached. https://about.gitlab.com/blog/two-sizes-fit-most-postgresql-and-clickhouse/ https://about.gitlab.com/blog/two-sizes-fit-most-postgresql-... https://news.ycombinator.com/item?id=44895954 https://news.ycombinator.com/item?id=44895954 The top submission is the end of a 4 part series. Part two is really nice on the details of how ClickHouse has focused on speeding updates: recommend a read! https://clickhouse.com/blog/updates-in-clickhouse-2-sql-style-updates https://clickhouse.com/blog/updates-in-clickhouse-2-sql-styl...

djfobbz 1y ago
I agree, I’ve been on CH since v20 and I thought I was the only one who noticed that they’ve been working very hard to bridge the gap between OLAP and OLTP. Sure, they’ll always be first class OLAP DB…but if you know how to get dangerous with its strengths, making it the goto datalake for your existing OLTP is pretty freaking awesome. Thanks for those shares