Resolving IllegalStateException Error in HASH_JOIN Operations – Dremio Support

Summary

You may encounter the following system error during query execution involving JOIN operations:

SYSTEM ERROR: IllegalStateException
SqlOperatorImpl HASH_JOIN

This error typically occurs when a record from the build side of a hash join exceeds the size limits of an internal memory page.

Relevant Versions

All Dremio Active Versions

Troubleshooting Steps

Verify the error by reviewing the query profile or job diagnostics to confirm the error origin is related to HASH_JOIN and includes:

SYSTEM ERROR: IllegalStateException
SqlOperatorImpl HASH_JOIN
ErrorOrigin: EXECUTOR

Test disabling the memory limit setting to see if it affects behavior:

ALTER SESSION SET exec.spillable.operators.static_memory_limit.enabled = false;

Modify your queries to exclude columns with large or complex data types (e.g., wide VARCHAR, deeply nested structures, arrays, maps) — especially from the build side of the join.
Confirm whether the issue persists. If disabling the setting or modifying the data resolves the issue, it indicates you're encountering a known limitation in the Dremio execution engine.

Cause

Dremio processes join operations by loading records from the build side (the smaller input used to construct an in-memory hash table) into fixed-size memory pages.

If even a single record is too large to fit into a page — typically due to wide fields or deeply nested structures — Dremio throws an IllegalStateException, and the join operation fails. This is a hard limitation of the current execution engine.

(We have a request open to improve the error message.)

Steps to Resolve

To avoid this error, follow these best practices:

Limit the size of records on the build side of the join.
- Select only the required columns needed for the join or post-join processing.
- Avoid including wide VARCHAR, large arrays, maps, or deeply nested fields unless necessary.

Modify the query to exclude problematic fields:

SELECT col1, col2, col3
FROM table_a
JOIN (
   SELECT key, colX  -- only required fields
   FROM table_b
) AS filtered_b ON table_a.key = filtered_b.key;

Optionally, test disabling the memory limit setting at the session level:
```
ALTER SESSION SET exec.spillable.operators.static_memory_limit.enabled = false;
```
⚠️ Note: This may not resolve the issue in all cases and should be used for testing or temporary relief only.
Split large fields (e.g., by using SUBSTRING) or filter out oversized data in earlier stages of the pipeline, if possible.

(We have a request open to improve the error message.)

Next Steps

Review query logic and minimize the footprint of the build side of joins.
Consider using explicit filtering or projection before joins.

Additional Resources

https://readyset.io/blog/introducing-hash-join-algorithm