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Documentation
/ Guides
/ Performance
My Workload Is Slow
If you find that your workload in DuckDB is slow, we recommend performing the following checks. More detailed instructions are linked for each point.
- Do you have enough memory? DuckDB works best if you have 5-10 GB memory per CPU core.
- Are you using a fast disk? Network-attached disks (such as cloud block storage) cause write-intenstive andlarger than memory workloads to slow down. For running such workloads in cloud environments, it is recommended to use instance-attached storage (NVMe SSDs).
- Are you using indexes or constraints (primary key, unique, etc.)? If possible, try disabling them, which boosts load and update performance.
- Are you using the correct types? For example, use
TIMESTAMPto encode datetime values. - Are you reading from Parquet files? If so, do they have row group sizes between 100k and 1M and file sizes between 100 MB to 10 GB?
- Does the query plan look right? Study it with
EXPLAIN. - Is the workload running in parallel? Use
htopor the operating system's task manager to observe this. - Is DuckDB using too many threads? Try limiting the amount of threads.
Are you aware of other common issues? If so, please click the Report content issue link below and describe them along with their workarounds.