> For loads with over 20k rows/s and people pushing changes, you may need a full-time person to handle the cluster and take a look at the crazy queries people are going to write.
I think this was a benefit of DBA culture in previous eras. Not that the DBAs were specifically necessary to write good queries (often they'd need to work with application teams to guide them towards schemas/behavior that worked well) or to maintain the database (managed DB offerings obsolete a lot of this work), but because they functioned as gatekeepers and rate-limiters of what queries and schemas could exist.
In that mode, DBAs functioned a bit like a human/process version of a thin microservice wrapping database access functionality. A big benefit was that the rate of change of queries/schema changes/access patterns was controlled and had a higher probability of being reviewed and thought about by humans before it went live. This also resulted in an increased end-database-user culture of trying to make existing schemas/query patterns work before jumping straight to bespoke access patterns. That culture's not what you want as e.g. a startup or pro-rapid-big-refactors shop, but it is what you want when your DB reliability needs or query rate/dataset size are high.
I don't think it's a given that a gatekeeper team is worth the overhead and cost; that's situational. I do think that the code version of that team (aforementioned microservice that wraps DB accesses/schema changes and nothing else) is usually not worth the cost. In my experience, that pretty much always reduces reliability and free performance gains that come from using direct DB clients from user code.
Most startups can just scale your traditional separation of compute & storage here though. You’d be shocked how well duckdb against s3 scales for 99.9% of use cases
It's one thing to be able to scale database compute/storage; it's another thing to be able to partition it. It's extremely common for bad queries/access patterns to cause noisy-neighbor effects on other simultaneous accesses to the database, to the extreme of knocking the whole database over with timeouts/OOMs/etc.
Scaling out DB compute can only help with that to a (expensive) point; eventually, you end up wanting to either prevent the bad queries from being added to the system (DBA culture) or ensure that the bad query runs on database infrastructure that doesn't affect other queries. That's why partitioning DB compute (and storage: noisy-neighbor effects from a bad query at the storage layer don't require storage to be running e.g. a BookKeeper or whatever on a server; they can manifest as hot S3 keys or cloud object/block store rate limiting events as well) is a necessary capability if your plan for dealing with a culture of "anyone can add any access pattern they want" is to scale the DB.
Instead we're... listen to this... we're going to take a software developer right. Just a normal developer right. We're going to make them be the database expert right. And the cloud expert. And we're going to put them on call. We're going to have them debug linux logs, and optimize our AWS costs. They'll be there for client escalation work. And big sales calls. From time to time we'll even have them do front end work.
I think a DBA/ops/infrastructure person as an imposed bottleneck is a useful capability in some environments.
But I won't follow you as far as "expecting developers to have expertise in how and where their software runs is unreasonable".
Like, yeah, it sucks that added DevOps responsibilities etc. don't come with adjusted compensation/time allocation expectations. I'm with you there.
But it's simultaneously true that a ton of "just regular developer" people are significant liabilities because they don't understand anything about the environment where their software runs. That liability manifests operationally (if someone's just running integration tests on Windows for their Java business logic changes and don't have any familiarity with e.g. the Linux, container, or cloud environments where their code runs, they're going to be useless when their code breaks in production and operations staff needs context), and it also makes them less effective when writing code--this culture of "developers should just live in business logic and not have to context-switch or fill their brains with other levels of the stack" is what leads to full table scans, lack of awareness of memory use, N+1 query hell, looping microservice dependencies, misunderstanding of what HTTP fields are set on requests that are mutated by load balancers, mistaken assumptions about how many instances of code can run and what concurrency/thread/coroutine behaviors are present, and so on. Those are very common problems, and it's incumbent on even ordinary developers to gain familiarity with how and where their code runs in order to write and maintain that code effectively.
If your code runs on Linux in Kubernetes, all of your developers should know how to read Linux system logs, check database sessions/queries issued by parts of the application, ls/grep/cat/strace/ps their way around, interpret k8s/application dashboards, check logs both in log storage and as they're emitted from a process, exec into a container, restart pods, check deployment liveness, etc. Even if they don't have permission to do those things in production.
That was true in 2005 when they deployed their code to IIS on Windows Server/MSSQL, too--just with different operational specifics.
That's a low bar that's still often unmet, and all sorts of teams suffer from that failure. Those skills can be trained, kept up to date, and hired for; I don't think there's a great excuse for not expecting them.
Apologies my comment was very tongue and cheek. I understand what you're getting at with regards to dedicated DB style teams being a potential bottleneck and not effective for every organization, as for example most orgs get by fine with a simple RDS instance with minimal management and optimization.
What I'm calling out practically is a de-specialization in roles and the trade-offs it imposes.
For example, the "jack of all trades master of one" that was already propagating under the guise of "Full stack engineer" or "DevOps" is further exasperated when those consolidated roles are also delegating critical knowledge acquisition to LLMs.
Further, as we consolidate roles and delegate knowledge acquisition to llms, we're also paying people less, giving less job security, lowering the general quality of life not just for developers, but for operations staff and users, and generally promoting total consolidation within big tech.
No apology needed; I understand what you're getting at, and I broadly agree. It's a spectrum between "extremely easy-to-hire people that operate in such a narrow niche that they're an operational liability with limited capabilities" and "expect everyone to be an expert at every level of the stack". The right point on that spectrum is different depending on context, but I do think that a majority of software shops would be better served by moving their required skillset more towards the generalist end of that spectrum, because the default is often far too niche (driven by poor tradeoffs and short-termism in service of growth/hiring, usually).
I wanna re-emphasize that this is not a new problem. It's not because of DevOps culture or cloud complexity or scale or whatever. Very limited-specialty people were always operational liabilities and had limited positive impact on feature delivery once you accounted for the help they needed to do anything that spanned multiple levels of the stack. There are just more engineers working on more systems with tighter timeline expectations now, so it seems like the complexity incumbent on the engineering role went up in general. It didn't (it went up in some situations and down in some situations), we just started noticing operational pain more often.
I definitely do agree that there's widespread ignorance of the velocity and difficulty-of-work tradeoffs that arise from requiring a wider range of specialties from engineers, and a similarly widespread failure to adjust compensation and timeline expectations accordingly.
Do any two teams actually operate it in anything like the same way though?
What I saw of it, especially some years ago, was it was highly particular, and everyone had their own odd habits built around running it, ingestion, querying, everything, to the point I suspect there are a non trivial number of companies using it where it is actually the core operational expertise of the company, despite them all appearing to be in totally different domains.
I'm aware; unfortunately that then leads to "must have a vendor approval" and a lot more process. If it were RDS, then it'd just be provision and done.
Where does ClickHouse fit between ElasticSearch, Pinot, TrinoDB, or just plain Spark? These are very different tools but I’m curious to know if any one has already compared them and can share some thoughts regarding their maintainability, QPS, latency, etc...
I would put it closest to Pinot though pinot makes different architectural choices about storage as a difference that stands out to me. Then i’d rank trino as a second closest in only some ways. Spark the furthest for sure.
It's defensive language for sure, i don't know how much it adds of protection in reality, but i nonethelesss sympathize with the author if he feels the need to protect himself that way or signaling the risk he takes.
When replaying customer queries against the next version, how do you compare results for queries using now() or approximate aggregates? Curious how you separate expected differences from actual regressions.
As an aside, I was stuck when turning on the Fulham v Crystal Palace game last week to find that Fulham have ClickHouse on their shirts this year, and Palace have Temporal AI. Talk about my worlds colliding.
I think this was a benefit of DBA culture in previous eras. Not that the DBAs were specifically necessary to write good queries (often they'd need to work with application teams to guide them towards schemas/behavior that worked well) or to maintain the database (managed DB offerings obsolete a lot of this work), but because they functioned as gatekeepers and rate-limiters of what queries and schemas could exist.
In that mode, DBAs functioned a bit like a human/process version of a thin microservice wrapping database access functionality. A big benefit was that the rate of change of queries/schema changes/access patterns was controlled and had a higher probability of being reviewed and thought about by humans before it went live. This also resulted in an increased end-database-user culture of trying to make existing schemas/query patterns work before jumping straight to bespoke access patterns. That culture's not what you want as e.g. a startup or pro-rapid-big-refactors shop, but it is what you want when your DB reliability needs or query rate/dataset size are high.
I don't think it's a given that a gatekeeper team is worth the overhead and cost; that's situational. I do think that the code version of that team (aforementioned microservice that wraps DB accesses/schema changes and nothing else) is usually not worth the cost. In my experience, that pretty much always reduces reliability and free performance gains that come from using direct DB clients from user code.
Scaling out DB compute can only help with that to a (expensive) point; eventually, you end up wanting to either prevent the bad queries from being added to the system (DBA culture) or ensure that the bad query runs on database infrastructure that doesn't affect other queries. That's why partitioning DB compute (and storage: noisy-neighbor effects from a bad query at the storage layer don't require storage to be running e.g. a BookKeeper or whatever on a server; they can manifest as hot S3 keys or cloud object/block store rate limiting events as well) is a necessary capability if your plan for dealing with a culture of "anyone can add any access pattern they want" is to scale the DB.
And get this. We pay them the exact same.
But I won't follow you as far as "expecting developers to have expertise in how and where their software runs is unreasonable".
Like, yeah, it sucks that added DevOps responsibilities etc. don't come with adjusted compensation/time allocation expectations. I'm with you there.
But it's simultaneously true that a ton of "just regular developer" people are significant liabilities because they don't understand anything about the environment where their software runs. That liability manifests operationally (if someone's just running integration tests on Windows for their Java business logic changes and don't have any familiarity with e.g. the Linux, container, or cloud environments where their code runs, they're going to be useless when their code breaks in production and operations staff needs context), and it also makes them less effective when writing code--this culture of "developers should just live in business logic and not have to context-switch or fill their brains with other levels of the stack" is what leads to full table scans, lack of awareness of memory use, N+1 query hell, looping microservice dependencies, misunderstanding of what HTTP fields are set on requests that are mutated by load balancers, mistaken assumptions about how many instances of code can run and what concurrency/thread/coroutine behaviors are present, and so on. Those are very common problems, and it's incumbent on even ordinary developers to gain familiarity with how and where their code runs in order to write and maintain that code effectively.
If your code runs on Linux in Kubernetes, all of your developers should know how to read Linux system logs, check database sessions/queries issued by parts of the application, ls/grep/cat/strace/ps their way around, interpret k8s/application dashboards, check logs both in log storage and as they're emitted from a process, exec into a container, restart pods, check deployment liveness, etc. Even if they don't have permission to do those things in production.
That was true in 2005 when they deployed their code to IIS on Windows Server/MSSQL, too--just with different operational specifics.
That's a low bar that's still often unmet, and all sorts of teams suffer from that failure. Those skills can be trained, kept up to date, and hired for; I don't think there's a great excuse for not expecting them.
What I'm calling out practically is a de-specialization in roles and the trade-offs it imposes.
For example, the "jack of all trades master of one" that was already propagating under the guise of "Full stack engineer" or "DevOps" is further exasperated when those consolidated roles are also delegating critical knowledge acquisition to LLMs.
Further, as we consolidate roles and delegate knowledge acquisition to llms, we're also paying people less, giving less job security, lowering the general quality of life not just for developers, but for operations staff and users, and generally promoting total consolidation within big tech.
I wanna re-emphasize that this is not a new problem. It's not because of DevOps culture or cloud complexity or scale or whatever. Very limited-specialty people were always operational liabilities and had limited positive impact on feature delivery once you accounted for the help they needed to do anything that spanned multiple levels of the stack. There are just more engineers working on more systems with tighter timeline expectations now, so it seems like the complexity incumbent on the engineering role went up in general. It didn't (it went up in some situations and down in some situations), we just started noticing operational pain more often.
I definitely do agree that there's widespread ignorance of the velocity and difficulty-of-work tradeoffs that arise from requiring a wider range of specialties from engineers, and a similarly widespread failure to adjust compensation and timeline expectations accordingly.
(note: the first part was originally published April 2025 according to the date tooltip)
What I saw of it, especially some years ago, was it was highly particular, and everyone had their own odd habits built around running it, ingestion, querying, everything, to the point I suspect there are a non trivial number of companies using it where it is actually the core operational expertise of the company, despite them all appearing to be in totally different domains.
But given the majority of use-cases of CH, AWS can be quite expensive.
Very true. Reading about "too many parts" gave me flashbacks.
(previously owned ingestion into CH at PostHog, no longer)