SQL search_type does not support slicing. slice_max will be…

Error message

SQL search_type does not support slicing. slice_max will be ignored.

What it means

A WARN from ElasticsearchSourceSplitEnumerator.getElasticsearchSplit: the job is configured with search_type=SQL but also sets slice_max > 1. SQL-based reads cannot be sliced, so the enumerator forces sliceMax to 1 and ignores the configured parallelism hint, producing a single split per index.

Solutions

Remove slice_max (or set it to 1) since SQL reads cannot be sliced
Switch search_type to DSL (or the slicing-capable type) if you need multi-slice parallel reading
Verify effective parallelism after the change — with this warn, each index yields exactly one split

Example fix

// before
search_type = SQL
slice_max = 5
// after
search_type = DSL
slice_max = 5
// (or keep SQL and delete slice_max)

Defensive patterns

Strategy: validation

Validate before calling

// validate config before submit (pseudo-check)
if (config.search_type == "SQL" && (config.slice_max ?? 1) > 1) {
  console.log("slice_max ignored with search_type=SQL; switch to DSL for slicing");
}

Prevention

Never combine search_type=SQL with slice_max > 1
Use search_type=DSL when index-size-based slicing/parallelism is needed
Confirm actual split count in job logs after changing search types

When it happens

Trigger: Configuring an Elasticsearch source with search_type = SQL and slice_max greater than 1; the enumerator builds splits (via newSplits) and detects the combination.

Common situations: Copy-pasting config between DSL/JSON jobs that used search_type=DSL (which supports slicing) and switching to SQL without removing slice_max; users expecting parallel SQL reads for large indices.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/be50dede8c21dbba. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-elasticsearch/src/main/java/org/apache/seatunnel/connectors/seatunnel/elasticsearch/source/ElasticsearchSourceSplitEnumerator.java:166

                }
            }
        }
    }

    private List<ElasticsearchSourceSplit> getElasticsearchSplit() {
        List<ElasticsearchSourceSplit> splits = new ArrayList<>();
        for (ElasticsearchConfig elasticsearchConfig : elasticsearchConfigs) {

            String index = elasticsearchConfig.getIndex();
            List<IndexDocsCount> indexDocsCounts = esRestClient.getIndexDocsCount(index);
            indexDocsCounts =
                    indexDocsCounts.stream()
                            .filter(x -> x.getDocsCount() != null && x.getDocsCount() > 0)
                            .sorted(Comparator.comparingLong(IndexDocsCount::getDocsCount))
                            .collect(Collectors.toList());
            int sliceMax = Math.max(1, elasticsearchConfig.getSliceMax());
            if (SearchTypeEnum.SQL.equals(elasticsearchConfig.getSearchType()) && sliceMax > 1) {
                log.warn("SQL search_type does not support slicing. slice_max will be ignored.");
                sliceMax = 1;
            }
            for (IndexDocsCount indexDocsCount : indexDocsCounts) {
                String indexName = indexDocsCount.getIndex();
                for (int sliceId = 0; sliceId < sliceMax; sliceId++) {
                    ElasticsearchConfig cloneCfg = elasticsearchConfig.clone();
                    cloneCfg.setIndex(indexName);
                    cloneCfg.setSliceId(sliceId);
                    cloneCfg.setSliceMax(sliceMax);
                    String splitId = sliceMax > 1 ? indexName + "#" + sliceId : indexName;
                    splits.add(new ElasticsearchSourceSplit(splitId, cloneCfg));
                }
            }
        }
        return splits;
    }

    @Override

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